VOLUTIONARY PRINCIPLES OF THOUGHT By: RICHARD J.KOSCIEJEW

EVOLUTIONARY PRINCIPLES OF THOUGHT
Presented by: RICHARD J.KOSCIEJEW
The history of science reveals that scientific knowledge and method did not emerge as full-blown from the minds of the ancient Greek any more than language and culture emerged fully formed in the minds of ‘Homo sapient’. ‘ Scientific knowledge is an extension of ordinary language into grater levels of abstraction and precision through reliance upon geometric and numerical relationships. We speculate that the seeds of the scientific imagination were planted in ancient Greece, as opposed to Chinese or Babylonian culture, partly because the social, political and an economic climate in Greece was more open to the pursuit of knowledge with marginal cultural utility. Another important factor was that the special character of Homeric religion allowed the Greeks to invent a conceptual framework that would prove useful in future scientific investigation. But it was only after this inheritance from Greek philosophy was wedded to some essential features of Judeo-Christian beliefs about the origin of the cosmos that the paradigm for classical physics emerged.
 The philosophical debate that had led to conclusions useful to the architects of classical physics can be briefly summarized, such when Thale’s fellow Milesian Anaximander claimed that the first substance, although indeterminate, manifested itself in a conflict of oppositions between hot and cold, moist and dry. The idea of nature as a self-regulating balance of forces was subsequently elaborated upon by Heraclitus (d. after 480 BC), who asserted that the fundamental substance is strife between opposites, which is itself the unity of the whole. It is, said Heraclitus, the tension between opposites that keeps the whole from simply ‘passing away.’
 Parmenides of Elea (B.c. 515 BC) argued in turn that the unifying substance is unique and static being. This led to a conclusion about the relationship between ordinary language and external reality that was later incorporated into the view of the relationship between mathematical language and physical reality. Since thinking or naming involves the presence of something, said Parmenides, thought and language must be dependent upon the existence of objects outside the human intellect. Presuming a one-to-one correspondence between word and idea and actual existing things, Parmenides concluded that our ability to think or speak of a thing at various times implies that it exists at all times. Hence the indivisible One does not change, and all perceived change is an illusion.
 These assumptions emerged in roughly the form in which they would be used by the creators of classical physics in the thought of the atomists. Leucippus : l. 450-420 BC and Democritus ©. 460-c. 370 BC ). They reconciled the two dominant and seemingly antithetical concepts of the fundamental character of being-Becoming ( Heraclitus ) and unchanging Being (Parmenides)-in a remarkable simple and direct way. Being, they said, is present in the invariable substance of the atoms that, through blending and separation, make up the thing of changing or becoming worlds.
 The last remaining feature of what would become the paradigm for the first scientific revolution in the seventeenth century is attributed to Pythagoras (Bc. 570 Bc). Like Parmenides, Pythagoras also held that the perceived world is illusory and that there is an exact correspondence between ideas and aspects of external reality. Pythagoras, however, had a different conception of the character of the idea that showed this correspondence. The truth about the fundamental character of the unified and unifying substance, which could be uncovered through reason and contemplation, is, he claimed, mathematical in form.
 Pythagoras established and was the cental figure in a school of philosophy, religion and mathematics; He was apparently viewed by his followers as semi-divine. For his followers the regular solids ( symmetrical three-dimensional forms in which all sides are the same regular polygons ) and whole numbers became revered essences of sacred ideas. In contrast with ordinary language, the language of mathematics and geometric forms seemed closed, precise and pure. Providing one understood the axioms and notations, and the meaning conveyed was invariant from one mind to another. The Pythagoreans felt that the language empowered the mind to leap beyond the confusion of sense experience into the realm of immutable and eternal essences. This mystical insight made Pythagoras the figure from antiquity most revered by the creators of classical physics, and it continues to have great appeal for contemporary physicists as they struggle with the epistemological implications of the quantum mechanical description of nature.
 Yet, least of mention, progress was made in mathematics, and to a lesser extent in physics, from the time of classical Greek philosophy to the seventeenth century in Europe. In Baghdad, for example, from about A.D. 750 to A.D. 1000, substantial advancement was made in medicine and chemistry, and the relics of Greek science were translated into Arabic, digested, and preserved. Eventually these relics reentered Europe via the Arabic kingdom of Spain and Sicily, and the work of figures like Aristotle universities of France, Italy, and England during the Middle Ages.
 For much of this period the Church provided the institutions, like the reaching orders, needed for the rehabilitation of philosophy. But the social, political and an intellectual climate in Europe was not ripe for a revolution in scientific thought until the seventeenth century. Until later in time, lest as far into the nineteenth century, the works of the new class of intellectuals we called scientists, whom of which were more avocations than vocation, and the word scientist do not appear in English until around 1840.
 Copernicus (1473-1543 ) would have been described by his contemporaries as an administrator, a diplomat, an avid student of economics and classical literature, and most notable, a highly honoured and placed church dignitaries. Although we named a revolution after him, his devoutly conservative man did not set out to create one. The placement of the Sun at the centre of the universe, which seemed right and necessary to Copernicus, was not a result of making careful astronomical observations. In fact, he made very few observations in the course of developing his theory, and then only to ascertain if his prior conclusions seemed correct. The Copernican system was also not any more useful in making astrological calculations than the accepted model and was, in some ways, much more difficult to implement. What, then, was his motivation for creating the model and his reasons for presuming that the model was correct?
 Copernicus felt that the placement of the Sun at the centre of the universe made sense because he viewed the Sun as the symbol of the presence of a supremely intelligent and intelligible God in a man-centred world. He was apparently led to this conclusion in part because the Pythagoreans believed that fire exists at the centre of the cosmos, and Copernicus identified this fire with the fireball of the Sun. the only support that Copernicus could offer for the greater efficacy of his model was that it represented a simpler and more mathematical harmonious model of the sort that the Creator would obviously prefer. The language used by Copernicus in ‘The Revolution of Heavenly Orbs,’ illustrates the religious dimension of his scientific thought: ‘In the midst of all the sun reposes, unmoving. Who, indeed, in this most beautiful temple would place the light-giver in any other part than from where it can illumine all other parts?’
 The belief that the mind of God as Divine Architect permeates the working of nature was the guiding principle of the scientific thought of Johannes Kepler ( or Keppler, 1571-1630 ). For this reason, most modern physicists would probably feel some discomfort in reading Kepler’s original manuscripts. Physics and metaphysics, astronomy and astrology, geometry and theology commingle with an intensity that might offend those who practice science in the modern sense of that word. Physical laws, wrote Kepler, ‘lie within the power of understanding of the human mind; God wanted us to perceive them when he created us of His own image, in order . . . that we may take part in His own thoughts. Our knowledge of numbers and quantities is the same as that of God’s, at least insofar as we can understand something of it in this mortal life.’
 Believing, like Newton after him, in the literal truth of the words of the Bible, Kepler concluded that the word of God is also transcribed in the immediacy of observable nature. Kepler’s discovery that the motions of the planets around the Sun were elliptical, as opposed perfecting circles, may have made the universe seem a less perfect creation of God on ordinary language. For Kepler, however, the new model placed the Sun, which he also viewed as the emblem of a divine agency, more at the centre of mathematically harmonious universes than the Copernican system allowed. Communing with the perfect mind of God requires as Kepler put it ‘knowledge of numbers and quantity.’
 Since Galileo did not use, or even refer to, the planetary laws of Kepler when those laws would have made his defence of the heliocentric universe more credible, his attachment to the god-like circle was probably a more deeply rooted aesthetic and religious ideal. But it was Galileo, even more than Newton, who was responsible for formulating the scientific idealism that quantum mechanics now force us to abandon. In ‘Dialogue Concerning the Two Great Systems of the World,’ Galileo said about the following about the followers of Pythagoras: ‘I know perfectly well that the Pythagoreans had the highest esteem for the science of number and that Plato himself admired the human intellect and believed that it participates in divinity solely because it is able to understand the nature of numbers. And I myself am inclined to make the same judgement.’
 This article of faith-mathematical and geometrical ideas mirror precisely the essences of physical reality was the basis for the first scientific law of this new science, a constant describing the acceleration of bodies in free fall, could not be confirmed by experiment. The experiments conducted by Galileo in which balls of different sizes and weights were rolled simultaneously down an inclined plane did not, as he frankly admitted, their precise results. And since a vacuum pumps had not yet been invented, there was simply no way that Galileo could subject his law to rigorous experimental proof in the seventeenth century. Galileo believed in the absolute validity of this law in the absence of experimental proof because he also believed that movement could be subjected absolutely to the law of number. What Galileo asserted, as the French historian of science Alexander Koyré put it, was ‘that the real are in its essence, geometrical and, consequently, subject to rigorous determination and measurement.’
 The popular image of Isaac Newton (1642-1727) is that of a supremely rational and dispassionate empirical thinker. Newton, like Einstein, had the ability to concentrate unswervingly on complex theoretical problems until they yielded a solution. But what most consumed his restless intellect were not the laws of physics. In addition to believing, like Galileo that the essences of physical reality could be read in the language of mathematics, Newton also believed, with perhaps even greater intensity than Kepler, in the literal truths of the Bible.
 For Newton the mathematical languages of physics and the language of biblical literature were equally valid sources of communion with the eternal writings in the extant documents alone consist of more than a million words in his own hand, and some of his speculations seem quite bizarre by contemporary standards. The Earth, said Newton, will still be inhabited after the day of judgement, and heaven, or the New Jerusalem, must be large enough to accommodate both the quick and the dead. Newton then put his mathematical genius to work and determined the dimensions required to house the population, his rather precise estimate was ‘the cube root of 12,000 furlongs.’
 The pint is, that during the first scientific revolution the marriage between mathematical idea and physical reality, or between mind and nature via mathematical theory, was viewed as a sacred union. In our more secular age, the correspondence takes on the appearance of an unexamined article of faith or, to borrow a phrase from William James (1842-1910), ‘an altar to an unknown god.’ Heinrich Hertz, the famous nineteenth-century German physicist, nicely described what there is about the practice of physics that tends to inculcate this belief: ‘One cannot escape the feeling that these mathematical formulae have an independent existence and intelligence of their own that they are wiser than we, wiser than their discoveries. That we get more out of them than was originally put into them.’
 While Hertz made this statement without having to contend with the implications of quantum mechanics, the feeling, the described remains the most enticing and exciting aspects of physics. That elegant mathematical formulae provide a framework for understanding the origins and transformations of a cosmos of enormous age and dimensions are a staggering discovery for bidding physicists. Professors of physics do not, of course, tell their students that the study of physical laws in an act of communion with thee perfect mind of God or that these laws have an independent existence outside the minds that discover them. The business of becoming a physicist typically begins, however, with the study of classical or Newtonian dynamics, and this training provides considerable covert reinforcement of the feeling that Hertz described.
 Perhaps, the best way to examine the legacy of the dialogue between science and religion in the debate over the implications of quantum non-locality is to examine the source of Einstein’s objections tp quantum epistemology in more personal terms. Einstein apparently lost faith in the God portrayed in biblical literature in early adolescence. But, as appropriated, . . . the ‘Autobiographical Notes’ give to suggest that there were aspects that carry over into his understanding of the foundation for scientific knowledge, . . . ‘Thus I came despite the fact that I was the son of an entirely irreligious [Jewish] Breeden heritage, which is deeply held of its religiosity, which, however, found an abrupt end at the age of 12. Though the reading of popular scientific books I soon reached the conviction that much in the stories of the Bible could not be true. The consequence waw a positively frantic [ orgy ] of freethinking coupled with the impression that youth is intentionally being deceived by the stat through lies that it was a crushing impression. Suspicion against every kind of authority grew out of this experience. . . . It was clear to me that the religious paradise of youth, which was thus lost, was a first attempt ti free myself from the chains of the ‘merely personal’. . . . The mental grasp of this extra-personal world within the frame of the given possibilities swam as highest aim half consciously and half unconsciously before the mind’s eye.’
 What is more, was, suggested Einstein, belief in the word of God as it is revealed in biblical literature that allowed him to dwell in a ‘religious paradise of youth’ and to shield himself from the harsh realities of social and political life. In an effort to recover that inner sense of security that was lost after exposure to scientific knowledge, or to become free once again of the ‘merely personal’, he committed himself to understanding the ‘extra-personal world within the frame of given possibilities’, or as seems obvious, to the study of physics. Although the existence of God as described in the Bible may have been in doubt, the qualities of mind that the architects of classical physics associated with this God were not. This is clear in the comments from which Einstein uses of mathematics, . . . ‘Nature is the realization of the simplest conceivable mathematical ideas. I am convinced that we can discover, by means of purely mathematical construction, those concepts and those lawful connections between them that furnish the key to the understanding of natural phenomena. Experience remains, of course, the sole criteria of physical utility of a mathematical construction. But the creative principle resides in mathematics. In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed.’
 This article of faith, first articulated by Kepler, that ‘nature is the realization of the simplest conceivable mathematical ideas’ allowed for Einstein to posit the first major law of modern physics much as it allows Galileo to posit the first major law of classical physics. During which time, when the special and then the general theories of relativity had not been confirmed by experiment and many established physicists viewed them as at least minor heresies, Einstein remained entirely confident of their predictions. Ilse Rosenthal-Schneider, who visited Einstein shortly after Eddington’s eclipse expedition confirmed a prediction of the general theory ( 1919 ), described Einstein’s response to this news: When I was giving expression to my joy that the results coincided with his calculations, he said quite unmoved, ‘But I knew the theory was correct,’ and when I asked, what if there had been no confirmation of his prediction, he countered: ‘Then I would have been sorry for the dear Lord  -the theory is correct.’
 Einstein was not given to making sarcastic or sardonic comments, particularly on matters of religion. These unguarded responses testify to his profound conviction that the language of mathematics allows the human mind access to immaterial and immutable truths existing outside of the mind that conceived them. Although Einstein’s belief was far more secular than Galileo’s, it retained the same essential ingredients.
 What continued in the twenty-three-year-long debate between Einstein and Bohr, least of mention? The primary article drawing upon its faith that contends with those opposing to the merits or limits of a physical theory, at the heart of this debate was the fundamental question, ‘What is the relationship between the mathematical forms in the human mind called physical theory and physical reality?’ Einstein did not believe in a God who spoke in tongues of flame from the mountaintop in ordinary language, and he could not sustain belief in the anthropomorphic God of the West. There is also no suggestion that he embraced ontological monism, or the conception of Being featured in Eastern religious systems, like Taoism, Hinduism, and Buddhism. The closest that Einstein apparently came to affirming the existence of the ‘extra-personal’ in the universe was a ‘cosmic religious feeling’, which he closely associated with the classical view of scientific epistemology.
 The doctrine that Einstein fought to preserve seemed the natural inheritance of physics until the advent of quantum mechanics. Although the mind that constructs reality might be evolving fictions that are not necessarily true or necessary in social and political life, there was, Einstein felt, a way of knowing, purged of deceptions and lies. He was convinced that knowledge of physical reality in physical theory mirrors the preexistent and immutable realm of physical laws. And as Einstein consistently made clear, this knowledge mitigates loneliness and inculcates a sense of order and reason in a cosmos that might appear otherwise bereft of meaning and purpose.
 What most disturbed Einstein about quantum mechanics was the fact that this physical theory might not, in experiment or even in principle, mirrors precisely the structure of physical reality. There is, for all the reasons we seem attested of, in that an inherent uncertainty in measurement made, . . . a quantum mechanical process reflects of a pursuit that quantum theory in itself and its contributive dynamic functionalities that there lay the attribution of a completeness of a quantum mechanical theory. Einstein’s fearing that it would force us to recognize that this inherent uncertainty applied to all of physics, and, therefore, the ontological bridge between mathematical theory and physical reality -does not exist. And this would mean, as Bohr was among the first to realize, that we must profoundly revive the epistemological foundations of modern science.
 The world view of classical physics allowed the physicist to assume that communion with the essences of physical reality via mathematical laws and associated theories was possible, but it made no other provisions for the knowing mind. In our new situation, the status of the knowing mind seems quite different. Modern physics distributively contributed its view toward the universe as an unbroken, undissectable and undivided dynamic whole. ‘There can hardly be a sharper contrast,’ said Melic Capek, ‘than that between the everlasting atoms of classical physics and the vanishing ‘particles’ of modern physics as Stapp put it: ‘Each atom turns out to be nothing but the potentialities in the behaviour pattern of others. What we find, therefore, are not elementary space-time realities, but rather a web of relationships in which no part can stand alone, every part derives its meaning and existence only from its place within the whole’’
 The characteristics of particles and quanta are not isolatable, given particle-wave dualism and the incessant exchange of quanta within matter-energy fields. Matter cannot be dissected from the omnipresent sea of energy, nor can we in theory or in fact observe matter from the outside. As Heisenberg put it decades ago, ‘the cosmos appears to be a complicated tissue of events, in which connection of different kinds alternate or overlay or combine and thereby determine the texture of the whole. This means that a pure reductionist approach to understanding physical reality, which was the goal of classical physics, is no longer appropriate.
 While the formalism of quantum physics predicts that correlations between particles over space-like separated regions are possible, it can say nothing about what this strange new relationship between parts ( quanta ) and whole ( cosmos ) was by means an outside formalism. This does not, however, prevent us from considering the implications in philosophical terms, as the philosopher of science Errol Harris noted in thinking about the special character of wholeness in modern physics, a unity without internal content is a blank or empty set and is not recognizable as a whole. A collection of merely externally related parts does not constitute a whole in that the parts will not be ‘mutually adaptive and complementary to one and another.’
 Wholeness requires a complementary relationship between unity and differences and is governed by a principle of organization determining the interrelationship between parts. This organizing principle must be universal to a genuine whole and implicit in all parts that constitute the whole, even though the whole is exemplified only in its parts. This principle of order, Harris continued, ‘is nothing really in and of itself. It is the way parts are organized and not another constituent addition to those that constitute the totality.’
 In a genuine whole, the relationship between the constituent parts must be ‘internal or immanent’ in the parts, as opposed to a mere spurious whole in which parts appear to disclose wholeness due to relationships that are external to the parts. The collection of parts that would allegedly constitute the whole in classical physics is an example of a spurious whole. Parts constitute a genuine whole when the universal principle of order is inside the parts and thereby adjusts each to all that they interlock and become mutually complementary. This not only describes the character of the whole revealed in both relativity theory and quantum mechanics. It is also consistent with the manner in which we have begun to understand the relation between parts and whole in modern biology.
 Modern physics also reveals, claims Harris, a complementary relationship between the differences between parts that constituted contentual representations that the universal ordering principle that is immanent in each of the parts. While the whole cannot be finally disclosed in the analysis of the parts, the study of the differences between parts provides insights into the dynamic structure of the whole present in each of the parts. The part can never, nonetheless, be finally isolated from the web of relationships that disclose the interconnections with the whole, and any attempt to do so results in ambiguity.
 Much of the ambiguity in attempted to explain the character of wholes in both physics and biology derives from the assumption that order exists between or outside parts. But order in complementary relationships between differences and sameness in any physical event is never external to that event  -the connections are immanent in the event. From this perspective, the addition of non-locality to this picture of the dynamic whole is not surprising. The relationship between part, as quantum event apparent in observation or measurement, and the undissectable whole, revealed but not described by the instantaneous, and the undissectable whole, revealed but described by the instantaneous correlations between measurements in space-like separated regions, is another extension of the part-whole complementarity to modern physics.
 If the universe is a seamlessly interactive system that evolves to a higher level of complexity, and if the lawful regularities of this universe are emergent properties of this system, we can assume that the cosmos is a singular point of significance as a whole that evinces of the ‘progressive principal order’ of complementary relations its parts. Given that this whole exists in some sense within all parts ( quanta ), one can then argue that it operates in self-reflective fashion and is the ground for all emergent complexities. Since human consciousness evinces self-reflective awareness in the human brain and since this brain, like all physical phenomena can be viewed as an emergent property of the whole, it is reasonable to conclude, in philosophical terms at least, that the universe is conscious.
 But since the actual character of this seamless whole cannot be represented or reduced to its parts, it lies, quite literally beyond all human representations or descriptions. If one chooses to believe that the universe be a self-reflective and self-organizing whole, this lends no support whatsoever to conceptions of design, meaning, purpose, intent, or plan associated with any mytho-religious or cultural heritage. However, If one does not accept this view of the universe, there is nothing in the scientific descriptions of nature that can be used to refute this position. On the other hand, it is no longer possible to argue that a profound sense of unity with the whole, which has long been understood as the foundation of religious experience, which can be dismissed, undermined or invalidated with appeals to scientific knowledge.
 While we have consistently tried to distinguish between scientific knowledge and philosophical speculation based on this knowledge  -there is no empirically valid causal linkage between the former and the latter. Those who wish to dismiss the speculative assumptions as its basis to be drawn the obvious freedom of which id firmly grounded in scientific theory and experiments there is, however, in the scientific description of nature, the belief in radical Cartesian division between mind and world sanctioned by classical physics. Seemingly clear, that this separation between mind and world was a macro-level illusion fostered by limited awarenesses of the actual character of physical reality and by mathematical idealization that were extended beyond the realm of their applicability.
 Thus, the grounds for objecting to quantum theory, the lack of a one-to-one correspondence between every element of the physical theory and the physical reality it describes, may seem justifiable and reasonable in strictly scientific terms. After all, the completeness of all previous physical theories was measured against the criterion with enormous success. Since it was this success that gave physics the reputation of being able to disclose physical reality with magnificent exactitude, perhaps a more comprehensive quantum theory will emerge to insist on these requirements.
 All indications are, however, that no future theory can circumvent quantum indeterminancy, and the success of quantum theory in co-ordinating our experience with nature is eloquent testimony to this conclusion. As Bohr realized, the fact that we live in a quantum universe in which the quantum of action is a given or an unavoidable reality requires a very different criterion for determining the completeness or physical theory. The new measure for a complete physical theory is that it unambiguously confirms our ability to co-ordinate more experience with physical reality.
 If a theory does so and continues to do so, which is certainly the case with quantum physics, then the theory must be deemed complete. Quantum physics not only works exceedingly well, it is, in these terms, the most accurate physical theory that has ever existed. When we consider that this physics allows us to predict and measure quantities like the magnetic moment of electrons to the fifteenth decimal place, we realize that accuracy per se is not the real issue. The real issue, as Bohr rightly intuited, is that this complete physical theory effectively undermines the privileged relationship in classical physics between ‘theory’ and ‘physical reality’.
 If the universe is a seamlessly interactive system that evolves to higher levels of complex and complicating regularities of which ae lawfully emergent in property of systems, we can assume that the cosmos is a single significant whole that evinces progressive order in complementary relations to its parts. Given that this whole exists in some sense within all parts ( quanta ), one can then argue that in operates in self-reflective fashion and is the ground from all emergent plexuities. Since human consciousness evinces self-reflective awareness in te human brain ( well protected between the cranium walls ) and since this brain, like all physical phenomena, can b viewed as an emergent property of the whole, it is unreasonable to conclude, in philosophical terms at least, that the universe is conscious.
 Nevertheless, since the actual character of this seamless whole cannot be represented or reduced to its parts, it lies, quite laterally, beyond all human representation or descriptions. If one chooses to believe that the universe be a self-reflective and self-organizing whole, this lends no support whatsoever to conceptual representation of design, meaning, purpose, intent, or plan associated with mytho-religious or cultural heritage. However, if one does not accept this view of the universe, there is noting in the scientific description of nature that can be used to refute this position. On the other hand, it is no longer possible to argue that a profound sense of unity with the whole, which has long been understood as foundation of religious experiences, but can be dismissed, undermined, or invalidated with appeals to scientific knowledge.
 While we have consistently tried to distinguish between scientific knowledge and philosophical speculation based on this of what is obtainable, let us be quite clear on one point - there is no empirically valid causal linkage between the former and the latter. Those who wish to dismiss the speculative base on which is obviously free to do as done. However, there is another conclusion to be drawn, in that is firmly grounded in scientific theory and experiment there is no basis in the scientific descriptions of nature for believing in the radical Cartesian division between mind and world sanctioned by classical physics. Clearly, his radical separation between mind and world was a macro-level illusion fostered by limited awareness of the actual character of physical reality nd by mathematical idealizations extended beyond the realms of their applicability.
 Nevertheless, the philosophical implications might prove in themselves as a criterial motive in debative consideration to how our proposed new understanding of the relationship between parts and wholes in physical reality might affect the manner in which we deal with some major real-world problems. This will issue to demonstrate why a timely resolution of these problems is critically dependent on a renewed dialogue between members of the cultures of human-social scientists and scientist-engineers. We will also argue that the resolution of these problems could be dependent on a renewed dialogue between science and religion.
 As many scholars have demonstrated, the classical paradigm in physics has greatly influenced and conditioned our understanding and management of human systems in economic and political realities. Virtually all models of these realities treat human systems as if they consist of atomized units or parts that interact with one another in terms of laws or forces external to or between the parts. These systems are also viewed as hermetic or closed and, thus, its discreteness, separateness and distinction.
 Consider, for example, how the classical paradigm influenced or thinking about economic reality. In the eighteenth and nineteenth centuries, the founders of classical economics  -figures like Adam Smith, David Ricardo, and Thomas Malthus conceived of the economy as a closed system in which intersections between parts (consumer, produces, distributors, etc.) are controlled by forces external to the parts (supply and demand). The central legitimating principle of free market economics, formulated by Adam Smith, is that lawful or law-like forces external to the individual units function as an invisible hand. This invisible hand, said Smith, frees the units to pursue their best interests, moves the economy forward, and in general legislates the behaviour of parts in the best vantages of the whole. (The resemblance between the invisible hand and Newton’s universal law of gravity and between the relations of parts and wholes in classical economics and classical physics should be transparent.)
 After roughly 1830, economists shifted the focus to the properties of the invisible hand in the interactions between pats using mathematical models. Within these models, the behaviour of pats in the economy is assumed to be analogous to the awful interactions between pats in classical mechanics. It is, therefore, not surprising that differential calculus was employed to represent economic change in a virtual world in terms of small or marginal shifts in consumption or production. The assumption was that the mathematical description of marginal shifts n the complex web of exchanges between parts (atomized units and quantities) and whole (closed economy) could reveal the lawful, or law-like, machinations of the closed economic system.
 These models later became one of the fundamentals for microeconomics. Microeconomics seek to describe interactions between parts in exact quantifiable measures-such as marginal cost, marginal revenue, marginal utility, and growth of total revenue as indexed against individual units of output. In analogy with classical mechanics, the quantities are viewed as initial conditions that can serve to explain subsequent interactions between parts in the closed system in something like deterministic terms. The combination of classical macro-analysis with micro-analysis resulted in what Thorstein Veblen in 1900 termed neoclassical economics-the model for understanding economic reality that is widely used today
 Beginning in the 1939s, the challenge became to subsume the understanding of the interactions between parts in closed economic systems with more sophisticated mathematical models using devices like linear programming, game theory, and new statistical techniques. In spite of the growing mathematical sophistication, these models are based on the same assumptions from classical physics featured in previous neoclassical economic theory-with one exception. They also appeal to the assumption that systems exist in equilibrium or in perturbations from equilibria, and they seek to describe the state of the closed economic system in these terms.
 One could argue that the fact that our economic models are  assumptions from classical mechanics is not a problem by appealing to the two-domain distinction between micro-level macro-level processes expatiated upon earlier. Since classical mechanic serves us well in our dealings with macro-level phenomena in situations where the speed of light is so large and the quantum of action is so small as to be safely ignored for practical purposes, economic theories based on assumptions from classical mechanics should serve us well in dealing with the macro-level behaviour of economic systems.
 The obvious problem, . . . acceded peripherally,  . . . nature is relucent to operate in accordance with these assumptions, in that the biosphere, the interaction between parts be intimately related to the hole, no collection of arts is isolated from the whole, and the ability of the whole to regulate the relative abundance of atmospheric gases suggests that the whole of the biota appear to display emergent properties that are more than the sum of its parts. What the current ecological crisis reveals in the abstract virtual world of neoclassical economic theory. The real economies are all human activities associated with the production, distribution, and exchange of tangible goods and commodities and the consumption and use of natural resources, such as arable land and water. Although expanding economic systems in the really economy ae obviously embedded in a web of relationships with the entire biosphere, our measure of healthy economic systems disguises this fact very nicely. Consider, for example, the healthy economic system written in 1996 by Frederick Hu, head of the competitive research team for the World Economic Forum - short of military conquest, economic growth is the only viable means for a country to sustain increases in natural living standards . . . An economy is internationally competitive if it performs strongly in three general areas: Abundant productive inputs from capital, labour, infrastructure and technology, optimal economic policies such as low taxes, little interference, free trade and sound market institutions. Such as the rule of law and protection of property rights.
 The prescription for medium-term growth of economies ion countries like Russia, Brazil, and China may seem utterly pragmatic and quite sound. But the virtual economy described is a closed and hermetically sealed system in which the invisible hand of economic forces allegedly results in a health growth economy if impediments to its operation are removed or minimized. It is, of course, often trued that such prescriptions can have the desired results in terms of increases in living standards, and Russia, Brazil and China are seeking to implement them in various ways.
 In the real economy, however, these systems are clearly not closed or hermetically sealed: Russia uses carbon-based fuels in production facilities that produce large amounts of carbon dioxide and other gases that contribute to global warming: Brazil is in the process of destroying a rain forest that is critical to species diversity and the maintenance of a relative abundance of atmospheric gases that regulate Earth temperature, and China is seeking to build a first-world economy based on highly polluting old-world industrial plants that burn soft coal. Not to forget, . . . the victual economic systems that the world now seems to regard as the best example of the benefits that can be derived form the workings of the invisible hand, that of the United States, operates in the real economy as one of the primary contributors to the ecological crisis.





















 In ‘Consilience,’ Edward O. Wilson makes to comment, the case that effective and timely solutions to the problem threatening human survival is critically dependent on something like a global revolution in ethical thought and behaviour. But his view of the basis for this revolution is quite different from our own. Wilson claimed that since the foundations for moral reasoning evolved in what he termed ‘gene-culture’ evolution, the rules of ethical behaviour re emergent aspects of our genetic inheritance. Based on the assumptions that the behaviour of contemporary hunter-gatherers resembles that of our hunter-gatherers forebears in the Palaeolithic Era, he drew on accounts of Bushman hunter-gatherers living in the centre Kalahari in an effort to demonstrate that ethical behaviour is associated with instincts like bonding, cooperation, and altruism.
 Wilson argued that these instincts evolved in our hunter-gatherer accessorial descendabilities, whereby genetic mutation and the ethical behaviour associated with these genetically based instincts provided a survival advantage. He then claimed that since these genes were passed on to subsequent generations of our dependable characteristics, which eventually became pervasive in the human genome, the ethical dimension of human nature has a genetic foundation. When we fully understand the ‘innate epigenetic rules of moral reasoning,’ it seems probable that the rules will probably turn out to be an ensemble of many algorithms whose interlocking activities guide the mind across a landscape of nuances moods and choices.
 Any reasonable attempt to lay a firm foundation beneath the quagmire of human ethics in all of its myriad and often contradictory formulations is admirable, and Wilson’s attempt is more admirable than most. In our view, however, there is little or no prospect that I will prove successful for a number of reasons. Wile te probability for us to discover some linkage between genes and behaviour, seems that the lightened path of human ethical behaviour and ranging advantages of this behaviour is far too complex, not o mention, inconsistently been reduced to a given set classification of ‘epigenetic ruled of moral reasoning.’
 Also, moral codes may derive in part from instincts that confer a survival advantage, but when we are t examine these codes, it also seems clear that they are primarily cultural products. This explains why ethical systems are constructed in a bewildering variety of ways in different cultural contexts and why they often sanction or legitimate quite different thoughts and behaviours. Let us not forget that rules f ethical behaviours are quite malleable and have been used to sacredly legitimate human activities such as slavery, colonial conquest, genocide and terrorism. As Cardinal Newman cryptically put it, ‘Oh how we hate one another for the love of God.’
 According to Wilson, the ‘human mind evolved to believe in the gods’ and people ‘need a sacred narrative’ to his view are merely human constructs and, therefore, there is no basis for dialogue between the world views of science and religion. ‘Science for its part, will test relentlessly every assumption about the human condition and in time uncover the bedrock of the moral and religiously sentient. The eventual result of the competition between the two world view, is believed, as I, will be the secularization of the human epic and of religion itself.
 Wilson obviously has a right to his opinions, and many will agree with him for their own good reasons, but what is most interesting about his thoughtful attempted to posit a more universal basis for human ethics in that it s based on classical assumptions about the character of both physical and biological realities. While Wilson does not argue that human’s behaviour is genetically determined in the strict sense, however, he does allege that there is a causal linkage between genes and behaviour that largely condition this behaviour, he appears to be a firm believer in classical assumption that reductionism can uncover the lawful essences that principally govern the physical aspects attributed to reality, including those associated with the alleged ‘epigenetic rules of moral reasoning.’
 Once, again, Wilson’s view is apparently nothing that cannot be reduced to scientific understandings or fully disclosed in scientific terms, and this apparency of hope for the future of humanity is that the triumph of scientific thought and method will allow us to achieve the Enlightenments ideal of disclosing the lawful regularities that govern or regulate all aspects of human experience. Hence, science will uncover the ‘bedrock of moral and religious sentiment, and the entire human epic will be mapped in the secular space of scientific formalism.’ The intent is not to denigrate Wilson’s attentive efforts to posit a more universal basis for the human condition, but is to demonstrate that any attempt to understand or improve upon the behaviour based on appeals to outmoded classical assumptions is unrealistic and outmoded. If the human mind did, in fact, evolve in something like deterministic fashion in gene-culture evolution -and if there were, in fact, innate mechanisms in mind that are both lawful and benevolent. Wilson’s program for uncovering these mechanisms could have merit. But for all th reasons that have been posited, classical determinism cannot explain the human condition and its evolutionary principle that govern in their functional dynamics, as Darwinian evolution should be modified to accommodate the complementary relationships between cultural and biological principles that governing evaluations do indeed have in them a strong, and firm grip upon genetical mutations that have attributively been the distribution in the contribution of human interactions with themselves in the finding to self-realizations and undivided wholeness.
 Equally important, the classical assumption that the only privileged or valid knowledge is scientific is one of the primary sources of the stark division between the two cultures of humanistic and scientists-engineers, in this view, Wilson is quite correct in assuming that a timely end to the two culture war and a renewer dialogue between members of these cultures is now critically important to human survival. It is also clear, however, that dreams of reason based on the classical paradigm will only serve to perpetuate the two-culture war. Since these dreams are also remnants of an old scientific word view that no longer applies in theory in fact, to the actual character of physical reality, as reality is a probable service to frustrate the solution for which in found of a real world problem.
 However, there is a renewed basis for dialogue between the two cultures, it is believed as quite different from that described by Wilson. Since classical epistemology has been displaced, or is the process of being displaced, by the new epistemology of science, the truths of science can no longer be viewed as transcendent ad absolute in the classical sense. The universe more closely resembles a giant organism than a giant machine, and it also displays emergent properties that serve to perpetuate the existence of the whole in both physics and biology that cannot be explained in terms of unrestricted determinism, simple causality, first causes, linear movements and initial conditions. Perhaps the first and most important precondition for renewed dialogue between the two cultural conflicting realizations as Einstein explicated upon its topic as, that a human being is a ‘part of the whole.’  It is this spared awareness that allows for the freedom, or existential choice of self-decision of choosing our free-will and the power to differentiate a direct cars to free ourselves of the ‘optical illusion’of our present conception of self as a ‘part limited in space and time’ and to widen ‘our circle of compassion to embrace al living creatures and the whole of nature in its beauty.’ Yet, one cannot, of course, merely reason oneself into an acceptance of this view, nonetheless, the inherent perceptions of the world are reason that the capacity for what Einstein termed ‘cosmic religious feedings.’ Perhaps, our enabling capability for that which is within us to have the obtainable ability to enabling of ours is to experience the self-realization, that of its realness is to sense its proven existence of a sense of elementarily leaving to some sorted conquering sense of universal consciousness, in so given to  arise the existence of the universe, which really makes an essential difference to the existence or its penetrative spark of awakening indebtednesses of reciprocality?
 Those who have this capacity will hopefully be able to communicate their enhanced scientific understanding of the relations among all aspects, and in part that is our self and the whole that are the universe in ordinary language wit enormous emotional appeal. The task lies before the poets of this renewing reality have nicely been described by Jonas Salk, which ‘man has come to the threshold of a state of consciousness, regarding his nature and his relationship to the Cosmos, in terms that reflects ‘reality.’ By using the processes of Nature and metaphor, to describe the forces by which it operates upon and within Man, we come as close to describing ‘reality’ as we can within te limits of our comprehension. Men will be very uneven in their capacity or such understanding, which, naturally, differs for different ages and cultures, and develops and changes over the course of time. For these reasons it will always be necessary to use metaphorical and mythical provisions as comprehensive guides to living. In this way. Man’s afforded efforts by the imagination and intellect can be playing the vital roles embarking upon the survival and his endurable evolution.
 It is time, if not, only, concluded  from evidence in its  suggestive conditional relation, for which the religious imagination and the religious experience to engage upon the complementary truths of science in fitting that silence with meaning, as having to antiquate a continual emphasis, least of mention, that does not mean that those who do not believe in the existence of God or Being, should refrain in any sense from assessing the impletions of the new truths of science. Understanding these implications does not necessitate any ontology, and is in no way diminished by the lack of any ontology. And one is free to recognize a basis for a dialogue between science and religion for the same reason that one is free to deny that this basis exists  -there is nothing in our current scientific world view that can prove the existence of God or Being and nothing that legitimate any anthropomorphic conceptions of the nature of God or Being. The question of belief in some ontology yet remains in what it has always been  -a question, and the physical universe on the most basic level remains what it always been a riddle. And the ultimate answer to the question and the ultimate meaning of the riddle is, and probably always will be, a matter of personal choice and conviction.
 The present time is clearly a time of a major paradigm shift, but consider the last great paradigm shift, the one that resulted in the Newtonian framework. This previous paradigm shift was profoundly problematic for the human spirit, it led to the conviction that we are strangers, freaks of nature, conscious beings in a universe that is almost entirely unconscious, and that, since the universe its strictly deterministic, even the free will we feel in regard to the movements of our bodies is an illusion. Yet it was probably necessary for the Western mind to go through the acceptance of such a paradigm.
 The overwhelming success of Newtonian physics led most scientists and most philosophers of the Enlightenment to rely on it exclusively. As far as the quest for knowledge about reality was concerned, they regarded all of the other mode’s of expressing human experience, such as accounts of numinous emergences, poetry, art, and so on, as irrelevant. This reliance on science as the only way to the truth about the universe s clearly obsoletes. Science has to give up the illusion of its self-sufficiency and self-sufficiency of human reason. It needs to unite with other modes of knowing, n particular with contemplation, and help each of us move to higher levels of being and toward the Experience of Oneness.
 If this is indeed the direction of the emerging world-view, then the paradigm shifts we are presently going through will prove to e nourishing to the human spirit and in correspondences with its deepest conscious or unconscious yearning  -the yearning to emerge out of Plato’s shadows and into the light of luminosity.
EVOLVING PRINCIPLES OF THOUGHT
                               
BOOK FOUR
SYSTEMATIC DELINEATION
Finding to a theory that magnifies the role of decisions, or free selection from among equally possible alternatives, in order to show that what appears to be objective or fixed by nature is in fact an artefact of human convention, similar to conventions of etiquette, or grammar, or law. Thus one might suppose that moral rules owe more to social convention than to anything imposed from outside, or have  supposedly inexorable necessities are in fact the shadow of our linguistic conventions. The disadvantage of conventionalism is that it must show that alternative, equally workable conventions could have been adopted, and it is often easy to believe that, for example, if we hold that some ethical norm such as respect for promises or property is conventional, we ought to be able to show that human needs would have been equally well satisfied by a system involving a different norm, and this may be hard to establish.
 A convention also suggested by Paul Grice (1913-88) directing participants in conversation to pay heed to an accepted purpose or direction of the exchange. Contributions made without paying this attention are liable to be rejected for other reasons than straightforward falsity: Something rue but unhelpful or inappropriate may meet with puzzlement or rejection. We can nevertheless, infer from the fact that it would be inappropriate to say something in some circumstance that what would be aid, were we to say it, would be false. This inference was frequently and in ordinary language philosophy, it being argued, for example, that since we do not normally say ‘there sees to be a barn there’ when there is unmistakably a barn there, it is false that on such occasions there seems to be a barn there.
 There are two main views on the nature of theories. According to the ‘received view’ theories are partially interpreted axiomatic systems, according to the semantic view, a theory is a collection of models (Suppe, 1974). However, a natural language comes ready interpreted, and the semantic problem is no that of the specification but of understanding the relationship between terms of various categories (names, descriptions, predicates, adverbs . . .) and their meanings. An influential proposal is that this relationship is best understood by attempting to provide a ‘truth definition’ for the language, which will involve giving terms and structure of different kinds have on the truth-condition of sentences containing them.
 The axiomatic method . . . as, . . . a proposition lid down as one from which we may begin, an assertion that we have taken as fundamental, at least for the branch of enquiry in hand. The axiomatic method is that of defining as a set of such propositions, and the ‘proof procedures’ or finding of how a proof ever gets started. Suppose I have as premises (1) p and (2) p ➞ q. Can I infer q? Only, it seems, if I am sure of, (3) (p & p ➞q) ➞q. Can I then infer q? Only, it seems, if I am sure that (4) (p & p ➞ q) ➞ q) ➞ q. For each new axiom (N) needing a further axiom (N + 1) telling me that the set so far implies q, and the regress never stops. The usual solution is to treat a system as containing not only axioms, but also rules of reference, allowing movement fro the axiom. The rule ‘modus ponens’ allow us to pass from the first two premises to 'q'. Charles Dodgson Lutwidge (1832-98) better known as Lewis Carroll’s puzzle shows that it is essential to distinguish two theoretical categories, although there may be choice about which to put in which category.
 This type of theory (axiomatic) usually emerges as a body of (supposes) truths that are not nearly organized, making the theory difficult to survey or study a whole. The axiomatic method is an idea for organizing a theory (Hilbert 1970): one tries to select from among the supposed truths a small number from which all others can be seen to be deductively inferable. This makes the theory rather more tractable since, in a sense, all the truths are contained in those few. In a theory so organized, the few truths from which all others are deductively inferred are called axioms. In that, just as algebraic and differential equations, which were used to study mathematical and physical processes, could they be made mathematical objects, so axiomatic theories, like algebraic and differential equations, which are means of representing physical processes and mathematical structures, could be made objects of mathematical investigation.
 In the traditional (as in Leibniz, 1704), many philosophers had the conviction that all truths, or all truths about a particular domain, followed from a few principles. These principles were taken to be either metaphysically prior or epistemologically prior or in the fist sense, they were taken to be entities of such a nature that what exists is ‘caused’ by them. When the principles were taken as epistemologically prior, that is, as axioms, they were taken to be epistemologically privileged either, e.g., self-evident, not needing to be demonstrated or (again, inclusive ‘or’) to be such that all truths do follow from them (by deductive inferences). Gödel (1984) showed that treating axiomatic theories as themselves mathematical objects, that mathematics, and even a small part of mathematics, elementary number theory, could not be axiomatized, that, more precisely, any class of axioms that in such that we could effectively decide, of any proposition, whether or not it was in the class, would be too small to capture all of the truths.
 The use of a model to test for the consistency of an axiomatized system is older than modern logic. Descartes’s algebraic interpretation of Euclidean geometry provides a way of showing that if the theory of real numbers is consistent, so is the geometry. Similar mapping had been used by mathematicians in the 19th century for example to show that if Euclidean geometry is consistent, so are various non-Euclidean geometries. Model theory is the general study of this kind of procedure: The study of interpretations of formal system. Proof theory studies relations of deductibility as defined purely syntactically, that is, without reference to the intended interpretation of the calculus. More formally, a deductively valid argument starting from true premises, that yields the conclusion between formulae of a system. But once the notion of an interpretation is in place we can ask whether a formal system meets certain conditions. In particular, can it lead us from sentences that are true under some interpretation to ones that are false under the same interpretation? And if a sentence is true under all interpretations, is it also a theorem of the system? We can define a notion of validity (a formula is valid if it is true in all interpretations) and semantic consequence (a formula, written
{A1 . . . An} ⊨ B, if it is true in all interpretations in which they are true) The central questions for a calculus will be whether all and only its theorems are valid, and whether {A1 . . . An} ⊨ B, if and only if {A1. . . . An} ⊢ B. These are the questions of the soundness and completeness of a formal system. For the propositional calculus this turns into the question of whether the proof theory delivers as theorems all and only tautologies. There are many axiomatizations of the propositional calculus that are consistent an complete. Gödel proved in 1929 that first-order predicate calculus is complete: any formula that is true under every interpretation is a theorem of the calculus.
 The propositional calculus or logical calculus whose expressions are character representation sentences or propositions, and constants representing operations on those propositions to produce others of higher complexity. The operations include conjunction, disjunction, material implication and negation (although these need not be primitive). Propositional logic was partially anticipated by the Stoics but researched maturity only with the work of Frége, Russell, and Wittgenstein.
 The concept introduced by Frége of a function taking a number of names as arguments, and delivering one proposition as the value. The idea is that ‘χ love’s y’ is a propositional function, which yields the proposition ‘John loves Mary’ from those two arguments (in that order). A propositional function is therefore roughly equivalent to a property or relation. In Principia Mathematica, Russell and Whitehead take propositional functions to be the fundamental function, since the theory of descriptions could be taken as showing that other expressions denoting functions are incomplete symbols.
 Keeping in mind, the two classical truth-values that a statement, proposition, or sentence can take. It is supposed in classical (two-valued) logic, that each statement has one of these values, and none has both. A statement is then false if and only if it is not true. The basis of this scheme is that to each statement there corresponds a determinate truth condition, or way the world must be for it to be true, and otherwise false. Statements may be felicitous or infelicitous in other dimensions (polite, misleading, apposite, witty, etc.) but truth is the central normative governing assertion. Considerations of vagueness may introduce greys into a black-and-white scheme. For the issue of whether falsity is the only way of failing to be true.
 Formally, it is nonetheless, that any suppressed premise or background framework of thought necessary to make an argument valid, or a position tenable. More formally, a presupposition has been defined as a proposition whose truth is necessary for either the truth or the falsity of another statement. Thus, if ‘p’ presupposes ‘q’, ‘q’ must be true for p to be either true or false. In the theory of knowledge of Robin George Collingwood (1889-1943), any propositions capable of truth or falsity stand on a bed of ‘absolute presuppositions’ which are not properly capable of truth or falsity, since a system of thought will contain no way of approaching such a question. It was suggested by Peter Strawson (1919-), in opposition to Russell’s theory of ‘definite’ descriptions, that ‘there exists a King of France’ is a presupposition of ‘the King of France is bald’, the latter being neither true, nor false, if there is no King of France. It is, however, a little unclear whether the idea is that no statement at all is made in such a case, or whether a statement i can made, but fails of being one a true and oppose of either true ids false. The former option preserves classical logic, since we can still say that every statement is either true or false, but the latter does not, since in classical logic the law of ‘bivalence’ holds, and ensures that nothing at all is presupposed for any proposition to be true or false. The introduction of presupposition therefore means that either a third truth-value is found, ‘intermediate’ between truth and falsity, or classical logic is preserved, but it is impossible to tell whether a particular sentence expresses a proposition that is a candidate for truth ad falsity, without knowing more than the formation rules of the language. Each suggestion carries costs, and there is some consensus that at least where definite descriptions are involved, examples like the one given are equally well handed by regarding the overall sentence false when the existence claim fails.
 A proposition may be true or false it is said to take the truth-value true, and if the latter the truth-value false. The idea behind the term is the analogy between assigning a propositional variable one or other of these values, as a formula of the propositional calculus, and assigning an object as the value of many other variable. Logics with intermediate values are called many-valued logics. Then, a truth-function of a number of propositions or sentences is a function of them that has a definite truth-value, depends only on the truth-values of the constituents. Thus (p & q) is a combination whose truth-value is true when ‘p’ is true and ‘q’ is true, and false otherwise, ¬ p is a truth-function of ‘p’, false when ‘p’ is true and true when ‘p’ is false. The way in which the value of the whole is determined by the combinations of values of constituents is presented in a truth table.
 In whatever manner, truths of fact cannot be reduced to any identity and our only way of knowing them is a posteriori, by reference to the facts of the empirical world.
 A proposition is knowable a priori if it can be known without experience of the specific course of events in the actual world. It may, however, be allowed that some experience is required to acquire the concepts involved in an a priori proposition. Some thing is knowable only a posteriori if it can be known a priori. The distinction given one of the fundamental problem areas of epistemology. The category of a priori propositions is highly controversial, since it is not clear how pure thought, unaided by experience, can give rise to any knowledge at all, and it has always been a concern of empiricism to deny that it can. The two great areas in which it seems to be so are logic and mathematics, so empiricists have commonly tried to show either that these are not areas of real, substantive knowledge, or that in spite of appearances their knowledge that we have in these areas is actually dependent on experience. The former line tries to show sense trivial or analytic, or matters of notation conventions of language. The latter approach is particularly y associated with Quine, who denies any significant slit between propositions traditionally thought of as a priori, and other deeply entrenched beliefs that occur in our overall view of the world.
 Another contested category is that of a priori concepts, supposed to be concepts that cannot be ‘derived’ from experience, but which are presupposed in any mode of thought about the world, time, substance, causation, number, and self are candidates. The need for such concept s, and the nature of the substantive a prior  knowledge to which they give rise, is the central concern of Kant ‘s Critique of Pure Reason.
 Likewise, since their denial does not involve a contradiction, there is merely contingent: Their could have been in other ways a hold of the actual world, but not every possible one. Some examples are ‘Caesar crossed the Rubicon’ and ‘Leibniz was born in Leipzig’, as well as propositions expressing correct scientific generalizations. In Leibniz’s view truths of fact rest on the principle of sufficient reason, which is a reason why it is so. This reason is that the actual world (by which he means the total collection of things past, present and future) is better than any other possible world and therefore created by God. The foundation of his thought is the conviction that to each individual there corresponds a complete notion, knowable only to God, from which is deducible all the properties possessed by the individual at each moment in its history. It is contingent that God actualizes te individual that meets such a concept, but his doing so is explicable by the principle of ‘sufficient reason’, whereby God had to actualize just that possibility in order for this to be the best of all possible worlds. This thesis is subsequently lampooned by Voltaire (1694-1778), in whom of which was prepared to take refuge in ignorance, as the nature of the soul, or the way to reconcile evil with divine providence.
 In defending the principle of sufficient reason sometimes described as the principle that nothing can be so without there being a reason why it is so. But the reason has to be of a particularly potent kind: eventually it has to ground contingent facts in necessities, and in particular in the reason an omnipotent and perfect being would have for actualizing one possibility than another. Among the consequences of the principle is Leibniz’s relational doctrine of space, since if space were an infinite box there could be no reason for the world to be at one point in rather than another, and God placing it at any point violate the principle. In Abelard’s (1079-1142), as in Leibniz, the principle eventually forces te recognition that the actual world is the best of all possibilities, since anything else would be inconsistent with the creative power that actualizes possibilities.
 If truth consists in concept containment, then it seems that all truths are analytic and hence necessary; and if they are all necessary, surely they are all truths of reason. In that not every truth can be reduced to an identity in a finite number of steps; in some instances revealing the connection between subject and predicate concepts would require an infinite analysis, while this may entail that we cannot prove such proposition as a prior, it does not appear to show that proposition could have been false. Intuitively, it seems a better ground for supposing that it is a necessary truth of a special sort. A related question arises from the idea that truths of fact depend on God’s decision to create the best world: If it is part of the concept of this world that it is best, how could its existence be other than necessary? An accountable and responsively answered explanation would be so, that any relational question that brakes the norm lay eyes on its existence in the manner other than hypothetical necessities, i.e., it follows from God’s decision to create the world, but God had the power to create this world, but God is necessary, so how could he have decided to do anything else? Leibniz says much more about these matters, but it is not clear whether he offers any satisfactory solutions.
 The view that the terms in which we think of some area are sufficiently infected with error for it to be better to abandon them than to continue to try to give coherent theories of their use. Eliminativism should be distinguished from scepticism that claims that we cannot know the truth about some area; eliminativism claims rather that there are no truth there to be known, in the terms that we currently think. An eliminativist about theology simply counsels abandoning the terms or discourse of theology, and that will include abandoning worries about the extent of theological knowledge.
 Eliminativists in the philosophy of mind counsel abandoning the whole network of terms mind, consciousness, self, qualia that usher in the problems of mind and body. Sometimes the argument for doing this is that we should wait for a supposed future understanding of ourselves, based on cognitive science and better than any our current mental descriptions provide, sometimes it is supposed that physicalism shows that no mental description of ourselves could possibly be true.
 Greek scepticism centred on the value of enquiry and questioning, scepticism is now the denial that knowledge or even rational belief is possible, either about some specific subject-matter, e.g., ethics, o r in any atra whatsoever. Classically, scepticism springs from the observation that the best methods in some area seem to fall short of giving us contact with the truth, e.g., there is a gulf between appearance and reality, and in frequency cites the conflicting judgements that our methods deliver, with the result that questions of truth become undecidable.
 Sceptical tendencies emerged in the 14th-century writings of Nicholas of Autrecourt. His criticisms of any certainty beyond the immediate deliverance of the senses and basic logic, and in particular of any knowledge of either intellectual or material substances, anticipate the later scepticism of Balye and Hume. The; later distinguishes between Pyrrhonistic and excessive scepticism, which he regarded as unlivable, and the more mitigated scepticism that accepts every day or commonsense beliefs (not as the delivery of reason, but as due more to custom and habit), but is duly wary of the power of reason to give us much more. Mitigated scepticism is thus closer to the attitude fostered by ancient scepticism from Pyrrho through to Sexus Empiricus. Although the phrase ‘Cartesian scepticism’ is sometimes used, Descartes himself was not a sceptic, but in the method of doubt, uses a sceptical scenario in order to begin the process of finding a secure mark of knowledge. Descartes himself trusts a category of ‘clear and distinct’ ideas, not far removed from the phantasia kataleptiké of the Stoics.
 Scepticism should not be confused with relativism, which is a doctrine about the nature of truth, and may be motivated by trying to avoid scepticism. Nor is it identical with eliminativism, which counsels abandoning an area of thought altogether, not because we cannot know the truth, but because there are no truths capable of being framed in the terms we use.
 Descartes’s theory of knowledge starts with the quest for certainty, for an indubitable starting-point or foundation on the basis alone of which progress is possible. This is eventually found in the celebrated ‘Cogito ergo sum’: I think therefore I am. By locating the point of certainty in my own awareness of my own self, Descartes gives a first-person twist to the theory of knowledge that dominated them following centuries in spite of various counter-attacks on behalf of social and public starting-points. The metaphysical associated with this priority are the famous Cartesian dualism, or separation of mind and matter into two different but interacting substances, Descartes rigorously and rightly sees that it takes divine dispensation to certify any relationship between the two realms thus divided, and to prove the reliability of the senses invokes a ‘clear and distinct perception’ of highly dubious proofs of the existence of a benevolent deity. This has not met general acceptance: as Hume drily puts it, ‘to have recourse to the veracity of the supreme Being, in order to prove the veracity of our senses, is surely making a very unexpected circuit’.
 In his own time Descartes’s conception of the entirely separate substance of the mind was recognized to give rise to insoluble problems of the nature of the causal connection between the two. It also gives rise to the problem, insoluble in its own terms, of other minds. Descartes’s notorious denial that non-human animals are conscious is a stark illustration of the problem. In his conception of matter Descartes also gives preference to rational cogitation over anything derived from the senses. Since we can conceive of the matter of a ball of wax surviving changes to its sensible qualities, matter is not an empirical concept, but eventually an entirely geometrical one, with extension and motion as its only physical nature. Descartes’s thought, as reflected in Leibniz, that the qualities of sense experience have no resemblance to qualities of things, so that knowledge of the external world is essentially knowledge of structure rather than of filling. On this basis Descartes erects a remarkable physics. Since matter is in effect the same as extension there can be no empty space or ‘void’, since there is no empty space motion is not a question of occupying previously empty space, but is to be thought of in terms of vortices (like the motion of a liquid).
 Although the structure of Descartes’s epistemology, theories of mind, and theory of matter have been rejected many times, their relentless exposure of the hardest issues, their exemplary clarity, and even their initial plausibility, all contrives to make him the central point of reference for modern philosophy.
 The self conceived as Descartes presents it in the first two Meditations: aware only of its own thoughts, and capable of disembodied existence, neither situated in a space nor surrounded by others. This is the pure self of ‘I-ness’ that we are tempted to imagine as a simple unique thing that make up our essential identity. Descartes’s view that he could keep hold of this nugget while doubting everything else is criticized by Lichtenberg and Kant, and most subsequent philosophers of mind.
 Descartes holds that we do not have any knowledge of any empirical proposition about anything beyond the contents of our own minds. The reason, roughly put, is that there is a legitimate doubt about all such propositions because there is no way to deny justifiably that our senses are being stimulated by some cause (an evil spirit, for example) which is radically different from the objects that we normally think affect our senses.
 He also points out, that the senses (sight, hearing, touch, etc., are often unreliable, and ‘it is prudent never to trust entirely those who have deceived us even once’, he cited such instances as the straight stick that looks ben t in water, and the square tower that look round from a distance. This argument of illusion, has not, on the whole, impressed commentators, and some of Descartes’ contemporaries pointing out that since such errors come to light as a result of further sensory information, it cannot be right to cast wholesale doubt on the evidence of the senses. But Descartes regarded the argument from illusion as only the first stage in softening up process which would ‘lead the mind away from the senses’. He admits that there are some cases of sense-base  belief about which doubt would be insane, e.g., the belief that I am sitting here by the fire, wearing a winter dressing gown’.
 Descartes was to realize that there was nothing in this view of nature that could explain or provide a foundation for the mental, or from direct experience as distinctly human. In a mechanistic universe, he said, there is no privileged place or function for mind, and the separation between mind and matter is absolute. Descartes was also convinced, that the immaterial essences that gave form and structure to this universe were coded in geometrical and mathematical ideas, and this insight led him to invent algebraic geometry.
 A scientific understanding of these ideas could be derived, said Descartes, with the aid of precise deduction, and he also claimed that the contours of physical reality could be laid out in three-dimensional coordinates. Following the publication of Newton’s Principia Mathematica in 1687, reductionism and mathematical modelling became the most powerful tools of modern science. And the dream that the entire physical world could be known and mastered through the extension and refinement of mathematical theory became the central feature and guiding principle of scientific knowledge.
 Having to its  recourse of knowledge, its cental questions include the origin of knowledge, the place of experience in generating knowledge, and the place of reason in doing so, the relationship between knowledge and certainty, and between knowledge and the impossibility of error, the possibility of universal scepticism, and the changing forms of knowledge that arise from new conceptualizations of the world. All of these issues link with other central concerns of philosophy, such as the nature of truth and the natures of experience and meaning.
 Foundationalism was associated with the ancient Stoics, and in the modern era with Descartes (1596-1650). Who discovered his foundations in the ‘clear and distinct’ ideas of reason? Its main opponent is Coherentism, or the view that a body of propositions mas be known without a foundation in certainty, but by their interlocking strength, than as a crossword puzzle may be known to have been solved correctly even if each answer, taken individually, admits of uncertainty. Difficulties at this point led the logical passivists to abandon the notion of an epistemological foundation altogether, and to flirt with the coherence theory of truth. It is widely accepted that trying to make the connection between thought and experience through basic sentences depends on an untenable ‘myth of the given’.
 Still in spite of these concerns, the problem, least of mention, is of defining knowledge in terms of true beliefs plus some favoured relations between the believer and the facts that began with Plato’s view in the ‘Theaetetus,’ that knowledge is true belief, and some logos. Due of its nonsynthetic epistemology, the enterprising of studying the actual formation of knowledge by human beings, without aspiring to certify those processes as rational, or its proof against ‘scepticism’ or even apt to yield the truth. Natural epistemology would therefore blend into the psychology of learning and the study of episodes in the history of science. The scope for ‘external’ or philosophical reflection of the kind that might result in scepticism or its refutation is markedly diminished. Despite the fact that the terms of modernity are so distinguished as exponents of the approach include Aristotle, Hume, and J. S. Mills.
 The task of the philosopher of a discipline would then be to reveal the correct method and to unmask counterfeits. Although this belief lay behind much positivist philosophy of science, few philosophers now subscribe to it. It places too well a confidence in the possibility of a purely previous ‘first philosophy’, or viewpoint beyond that of the work one’s way of practitioners, from which their best efforts can be measured as good or bad. These standpoints now seem that too many philosophers to be a fanciefancy, that the more modest of tasks that are actually adopted at various historical stages of investigation into different areas with the aim not so much of criticizing but more of systematization, in the presuppositions of a particular field at a particular tie. There is still a role for local methodological disputes within the community  investigators of some phenomenon, with one approach charging that another is unsound or unscientific, but logic and philosophy will not, on the modern view, provide an independent arsenal of weapons for such battles, which indeed often come to seem more like political bids for ascendancy within a discipline.
 This is an approach to the theory of knowledge that sees an important connection between the growth of knowledge and biological evolution. An evolutionary epistemologist claims that the development of human knowledge processed through some natural selection process, the best example of which is Darwin’s theory of biological natural selection. There is a widespread misconception that evolution proceeds according to some plan or direct, but it has neither, and the role of chance ensures that its future course will be unpredictable. Random variations in individual organisms create tiny differences in their Darwinian fitness. Some individuals have more offsprings than others, and the characteristics that increased their fitness thereby become more prevalent in future generations. Once upon a time, at least a mutation occurred in a human population in tropical Africa that changed the haemoglobin molecule in a way that provided resistance to malaria. This enormous advantage caused the new gene to spread, with the unfortunate consequence that sickle-cell anaemia came to exist.
 Chance can influence the outcome at each stage: First, in the creation of genetic mutation, second, in wether the bearer lives long enough to show its effects, thirdly, in chance events that influence the individual’s actual reproductive success, and fourth, in whether a gene even if favoured in one generation, is, happenstance, eliminated in the next, and finally in the many unpredictable environmental changes that will undoubtedly occur in the history of any group of organisms. As Harvard biologist Stephen Jay Gould has so vividly expressed that process over again, the outcome would surely be different. Not only might there not be humans, there might not even be anything like mammals.
 We will often emphasis the elegance of traits shaped by natural selection, but the common idea that nature creates perfection needs to be analysed carefully. The extent to which evolution achieves perfection depends on exactly what you mean. If you mean ‘Does natural selections always take the best path for the long-term welfare of a species?’ The answer is no. That would require adaption by group selection, and this is, unlikely. If you mean ‘Does natural selection creates every adaption that would be valuable?’ The answer again, is no. For instance, some kinds of South American monkeys can grasp branches with their tails. The trick would surely also be useful to some African species, but, simply because of bad luck, none have it. Some combination of circumstances started some ancestral South American monkeys using their tails in ways that ultimately led to an ability to grab onto branches, while no such development took place in Africa. Mere usefulness of a trait does not necessitate a means in that what will understandably endure phylogenesis or evolution.
 This is an approach to the theory of knowledge that sees an important connection between the growth of knowledge and biological evolution. An evolutionary epistemologist claims that the development of human knowledge proceeds through some natural selection process, the best example of which is Darwin’s theory of biological natural selection.  The three major components of the model of natural selection are variation selection and retention. According to Darwin’s theory of natural selection, variations are not pre-designed to do certain functions. Rather, these variations that do useful functions are selected. While those that do not employ of some coordinates in that are regainfully purposed are also, not to any of a selection, as duly influenced of such a selection, that may have responsibilities for the visual aspects of a variational intentionally occurs. In the modern theory of evolution, genetic mutations provide the blind variations: Blind in the sense that variations are not influenced by the effects they would have-the likelihood of a mutation is not correlated with the benefits or liabilities that mutation would confer on the organism, the environment provides the filter of selection, and reproduction provides the retention. Fatnesses are achieved because those organisms with features that make them less adapted for survival do not survive in connection with other organisms in the environment that have features that are better adapted. Evolutionary epistemology applies this blind variation and selective retention model to the growth of scientific knowledge and to human thought processes overall.
 The parallel between biological evolution and conceptual or ‘epistemic’ evolution can be seen as either literal or analogical. The literal version of evolutionary epistemology deeds biological evolution as the main cause of the growth of knowledge. On this view, called the ‘evolution of cognitive mechanic programs’, by Bradie (1986) and the ‘Darwinian approach to epistemology’ by Ruse (1986), that growth of knowledge occurs through blind variation and selective retention because biological natural selection itself is the cause of epistemic variation and selection. The most plausible version of the literal view does not hold that all human beliefs are innate but rather than the mental mechanisms that guide the acquisitions of non-innate beliefs are themselves innately and the result of biological natural selection. Ruse, (1986) demands of a version of literal evolutionary epistemology that he links to sociolology (Rescher, 1990).
 On the analogical version of evolutionary epistemology, called the ‘evolution of theory’s program’, by Bradie (1986). The ‘Spenserians approach’ (after the nineteenth century philosopher Herbert Spencer) by Ruse (1986), the development of human knowledge is governed by a process analogous to biological natural selection, rather than by an instance of the mechanism itself. This version of evolutionary epistemology, introduced and elaborated by Donald Campbell (1974) as well as Karl Popper, sees the [partial] fit between theories and the world as explained by a mental process of trial and error known as epistemic natural selection.
 Both versions of evolutionary epistemology are usually taken to be types of naturalized epistemology, because both take some empirical facts as a starting point for their epistemological project. The literal version of evolutionary epistemology begins by accepting evolutionary theory and a materialist approach to the mind and, from these, constructs an account of knowledge and its developments. In contrast, the metaphorical version does not require the truth of biological evolution: It simply draws on biological evolution as a source for the model of natural selection. For this version of evolutionary epistemology to be true, the model of natural selection need only apply to the growth of knowledge, not to the origin and development of species. Crudely put, evolutionary epistemology of the analogical sort could still be true even if Creationism is the correct theory of the origin of species.
 Although they do not begin by assuming evolutionary theory, most analogical evolutionary epistemologists are naturalized epistemologists as well, their empirical assumptions, least of mention, implicitly come from psychology and cognitive science, not evolutionary theory. Sometimes, however, evolutionary epistemology is characterized in a seemingly non-naturalistic fashion. Campbell (1974) says that ‘if one is expanding knowledge beyond what one knows, one has no choice but to explore without the benefit of wisdom’, i.e., blindly. This, Campbell admits, makes evolutionary epistemology close to being a tautology (and so not naturalistic). Evolutionary epistemology does assert the analytic claim that when expanding one’s knowledge beyond what one knows, one must precessed to something that is already known, but, more interestingly, it also makes the synthetic claim that when expanding one’s knowledge beyond what one knows, one must proceed by blind variation and selective retention. This claim is synthetic because it can be empirically falsified. The central claim of evolutionary epistemology is synthetic, not analytic. If the central contradictory, which they are not. Campbell is right that evolutionary epistemology does have the analytic feature he mentions, but he is wrong to think that this is a distinguishing feature, since any plausible epistemology has the same analytic feature (Skagestad, 1978).
 Two extraordinary issues lie to awaken the literature that involves questions about ‘realism’, i.e., What metaphysical commitment does an evolutionary epistemologist have to make? Progress, i.e., according to evolutionary epistemology, does knowledge develop toward a goal? With respect to realism, many evolutionary epistemologists endorse that is called ‘hypothetical realism’, a view that combines a version of epistemological ‘scepticism’ and tentative acceptance of metaphysical realism. With respect to progress, the problem is that biological evolution is not goal-directed, but the growth of human knowledge seems to be. Campbell (1974) worries about the potential dis-analogy here but is willing to bite the stone of conscience and admit that epistemic evolution progress toward a goal (truth) while biologic evolution does not. Many another has argued that evolutionary epistemologists must give up the ‘truth-topic’ sense of progress because a natural selection model is in essence, is non-teleological, as an alternative, following Kuhn (1970), and embraced in the accompaniment with evolutionary epistemology.
 Among the most frequent and serious criticisms levelled against evolutionary epistemology is that the analogical version of the view is false because epistemic variation is not blind (Skagestad, 1978, 613-16, and Ruse, 1986, ch.2 (. Stein and Lipton (1990) have argued, however, that this objection fails because, while epistemic variation is not random, its constraints come from heuristics that, for the most part, are selective retention. Further, Stein and Lipton come to the conclusion that heuristics are analogous to biological pre-adaptions, evolutionary pre-biological pre-adaptions, evolutionary cursors, such as a half-wing, a precursor to a wing, which have some function other than the function of their descendable structures: The function of descendable structures, the function of their descendable character embodied to its structural foundations, is that of the guidelines of epistemic variation is, on this view, not the source of disanalogy, but the source of a more articulated account of the analology.
 Many evolutionary epistemologists try to combine the literal and the analogical versions (Bradie, 1986, and Stein and Lipton, 1990), saying that those beliefs and cognitive mechanisms, which are innate results from natural selection of the biological sort and those that are innate results from natural selection of the epistemic sort. This is reasonable as long as the two parts of this hybrid view are kept distinct. An analogical version of evolutionary epistemology with biological variation as its only source of blondeness would be a null theory: This would be the case if all our beliefs are innate or if our non-innate beliefs are not the result of blind variation. An appeal to the legitimate way to produce a hybrid version of evolutionary epistemology since doing so trivializes the theory. For similar reasons, such an appeal will not save an analogical version of evolutionary epistemology from arguments to the effect that epistemic variation is blind (Stein and Lipton, 1990).
 Although it is a new approach to theory of knowledge, evolutionary epistemology has attracted much attention, primarily because it represents a serious attempt to flesh out a naturalized epistemology by drawing on several disciplines. In science is relevant to understanding the nature and development of knowledge, then evolutionary theory is among the disciplines worth a look. Insofar as evolutionary epistemology looks there, it is an interesting and potentially fruitful epistemological programme.
 What makes a belief justified and what makes a true belief knowledge? Thinking that whether a belief deserves one of these appraisals is natural depends on what caused the depicted branch of knowledge to have the belief. In recent decades a number of epistemologists have pursued this plausible idea with a variety of specific proposals. Some causal theories of knowledge have it that a true belief that ‘p’ is knowledge just in case it has the right causal connection to the fact that ‘p’. Such a criterion can be applied only to cases where the fact that ‘p’ is a sort that can enter into causal relations, as this seems to exclude mathematically and the necessary facts and perhaps any fact expressed by a universal generalization, and proponents of this sort of criterion have usually supposed that it is limited to perceptual representations where knowledge of particular facts about subjects’ environments.
 For example, Armstrong (1973), predetermined that a  position held by a belief in the form ‘This perceived object is ‘F’ is [non-inferential] knowledge if and only if the belief is a completely reliable sign that the perceived object is ‘F’, that is, the fact that the object is ‘F’ contributed to causing the belief and its doing so depended on properties of the believer such that the laws of nature dictated that, for any subject ‘χ’ and perceived object ‘y’, if ‘χ’ has those properties and believed that ‘y’ is ‘F’, then ‘y’ is ‘F’. (Dretske (1981) offers a rather similar account, in terms of the belief’s being caused by a signal received by the perceiver that carries the information that the object is ‘F’).
 Goldman (1986) has proposed an importantly different causal criterion, namely, that a true belief is knowledge if it is produced by a type of process that is ‘globally’ and ‘locally’ reliable. Causing true beliefs is sufficiently high is globally reliable if its propensity. Local reliability has to do with whether the process would have produced a similar but false belief in certain counterfactual situations alternative to the actual situation. This way of marking off true beliefs that are knowledge does not require the fact believed to be causally related to the belief, and so it could in principle apply to knowledge of any kind of truth.
 Goldman requires the global reliability of the belief-producing process for the justification of a belief, he requires it also for knowledge because justification is required for knowledge. What he requires for knowledge, but does not require for justification is local reliability. His idea is that a justified true belief is knowledge if the type of process that produced it would not have produced it in any relevant counterfactual situation in which it is false. Its purported theory of relevant alternatives can be viewed as an attempt to provide a more satisfactory response to this tension in our thinking about knowledge. It attempts to characterize knowledge in a way that preserves both our belief that knowledge is an absolute concept and our belief that we have knowledge.
 According to the theory, we need to qualify rather than deny the absolute character of knowledge. We should view knowledge as absolute, reactive to certain standards (Dretske, 1981 and Cohen, 1988). That is to say, in order to know a proposition, our evidence need not eliminate all the alternatives to that preposition, rather for ‘us’, that we can know our evidence eliminates al the relevant alternatives, where the set of relevant alternatives (a proper subset of the set of all alternatives) is determined by some standard. Moreover, according to the relevant alternatives view, and the standards determining that of the alternatives is raised by the sceptic are not relevant. If this is correct, then the fact that our evidence cannot eliminate the sceptic’s alternative does not lead to a sceptical result. For knowledge requires only the elimination of the relevant alternatives, so the relevant alternative view preserves in both strands in our thinking about knowledge. Knowledge is an absolute concept, but because the absoluteness is relative to a standard, we can know many things.
 The interesting thesis that counts as a causal theory of justification (in the meaning of ‘causal theory’ intended here) is that: A belief is justified in case it was produced by a type of process that is ‘globally’ reliable, that is, its propensity to produce true beliefs-that can be defined (to a good approximation) As the proportion of the beliefs it produces (or would produce) that is true  is sufficiently great.
 This proposal will be adequately specified only when we are told (i) how much of the causal history of a belief counts as part of the process that produced it, (ii) which of the many types to which the process belongs is the type for purposes of assessing its reliability, and (iii) relative to why the world or worlds are the reliability of the process type to be assessed  the actual world, the closet worlds containing the case being considered, or something else? Let ‘us’ look at the answers suggested by Goldman, the leading proponent of a reliabilist account of justification.
   (1) Goldman (1979, 1986) takes the relevant belief producing process to include only the proximate causes internal to the believer. So, for instance, when recently I believed that the telephone was ringing the process that produced the belief, for purposes of assessing reliability, includes just the causal chain of neural events from the stimulus in my ear’s inward ands other concurrent brain states on which the production of the belief depended: It does not include any events’ as the telephone, or the sound waves travelling between it and my ears, or any earlier decisions I made that were responsible for my being within hearing distance of the telephone at that time. It does seem intuitively plausible of a belief depends should be restricted to internal omnes proximate to the belief. Why? Goldman does not tell ‘us’. One answer that some philosophers might give is that it is because a belief’s being justified at a given time can depend only on facts directly accessible to the believer’s awareness at that time (for, if a believer ought to holds only beliefs that are justified, she can tell at any given time what beliefs would then be justified for her). However, this cannot be Goldman’s answer because he wishes to include in the relevantly process neural events that are not directly accessible to consciousness.
   (2) Once the reliabilist has told ‘us’ how to delimit the process producing a belief, he needs to tell ‘us’ which of the many types to which it belongs is the relevant type. Coincide, for example, the process that produces your current belief that you see a book before you. One very broad type to which that process belongs would be specified by ‘coming to a belief as to something one perceives as a result of activation of the nerve endings in some of one’s sense-organs’. A constricted type, in which that unvarying processes belong would be specified by ‘coming to a belief as to what one sees as a result of activation of the nerve endings in one’s retinas’. A still narrower type would be given by inserting in the last specification a description of a particular pattern of activation of the retina’s particular cells. Which of these or other types to which the token process belongs is the relevant type for determining whether the type of process that produced your belief is reliable?
 If we select a type that is too broad, as having the same degree of justification various beliefs that intuitively seem to have different degrees of justification. Thus the broadest type we specified for your belief that you see a book before you apply also to perceptual beliefs where the object seen is far away and seen only briefly is less justified. On the other hand, is we are allowed to select a type that is as narrow as we please, then we make it out that an obviously unjustified but true belief is produced by a reliable type of process. For example, suppose I see a blurred shape through the fog far in a field and unjustifiedly, but correctly, believe that it is a sheep: If we include enough details about my retinal image is specifying te type of the visual process that produced that belief, we can specify a type is likely to have only that one instanced and is therefore 100 percent reliable. Goldman conjectures (1986) that the relevant process type is ‘the narrowest type that is casually operative’. Presumably, a feature of the process producing beliefs were causally operatives in producing it just in case some alternative feature instead, but it would not have led to that belief. (We need to say ‘some’ here rather than ‘any’, because, for example, when I see an oak or pine tree, the particular ‘like-minded’ material bodies of my retinal image are casually clearly toward the operatives in producing my belief that what is seen as a tree, even though there are alternative shapes, for example, ‘pineish’ or ‘birchness’ ones, that would have produced the same belief.)
   (3) Should the justification of a belief in a hypothetical, non-actual example turn on the reliability of the belief-producing process in the possible world of the example? That leads to the implausible result in that in a world run by a Cartesian demon-a powerful being who causes the other inhabitants of the world to have rich and coherent sets of perceptual and memory impressions that are all illusory the perceptual and memory beliefs of the other inhabitants are all unjustified, for they are produced by processes that are, in that world, quite unreliable. If we say instead that it is the reliability of the processes in the actual world that matters, we get the equally undesired result that if the actual world is a demon world then our perceptual and memory beliefs are all unjustified.
 Goldman’s solution (1986) is that the reliability of the process types is to be gauged by their performance in ‘normal’ worlds, that is, worlds consistent with ‘our general beliefs about the world  . . . ‘about the sorts of objects, events and changes that occur in it’. This gives the intuitively right results for the problem cases just considered, but indicate by inference an implausible proportion of making compensations for alternative tending toward justification. If there are people whose general beliefs about the world are very different from mine, then there may, on this account, be beliefs that I can correctly regard as justified (ones produced by processes that are reliable in what I take to be a normal world) but that they can correctly regard as not justified.
 However, these questions about the specifics are dealt with, and there are reasons for questioning the basic idea that the criterion for a belief’s being justified is its being produced by a reliable process. Thus and so, doubt about the sufficiency of the reliabilist criterion is prompted by a sort of example that Goldman himself uses for another purpose. Suppose that being in brain-state ‘B’ always causes one to believe that one is in brained-state ‘B’. Here the reliability of the belief-producing process is perfect, but ‘we can readily imagine circumstances in which a person goes into grain-state ‘B’ and therefore has the belief in question, though this belief is by no means justified’ (Goldman, 1979). Doubt about the necessity of the condition arises from the possibility that one might know that one has strong justification for a certain belief and yet that knowledge is not what actually prompts one to believe. For example, I might be well aware that, having read the weather bureau’s forecast that it will be much hotter tomorrow. I have ample reason to be confident that it will be hotter tomorrow, but I irrationally refuse to believe it until Wally tells me that he feels in his joints that it will be hotter tomorrow. Here what prompts me to believe dors not justify my belief, but my belief is nevertheless justified by my knowledge of the weather bureau’s prediction and of its evidential force: I can advert to any disavowable inference that I ought not to be holding the belief. Indeed, given my justification and that there is nothing untoward about the weather bureau’s prediction, my belief, if true, can be counted knowledge. This sorts of example raises doubt whether any causal conditions, are it a reliable process or something else, is necessary for either justification or knowledge.
 Philosophers and scientists alike, have often held that the simplicity or parsimony of a theory is one reason, all else being equal, to view it as true. This goes beyond the unproblematic idea that simpler theories are easier to work with and gave greater aesthetic appeal.
 One theory is more parsimonious than another when it postulates fewer entities, processes, changes or explanatory principles: The simplicity of a theory depends on essentially the same consecrations, though parsimony and simplicity obviously become the same. Demanding clarification of what makes one theory simpler or more parsimonious is plausible than another before the justification of these methodological maxims can be addressed.
 If we set this description problem to one side, the major normative problem is as follows: What reason is there to think that simplicity is a sign of truth? Why should we accept a simpler theory instead of its more complex rivals? Newton and Leibniz thought that the answer was to be found in a substantive fact about nature. In ‘Principia,’ Newton laid down as his first Rule of Reasoning in Philosophy that ‘nature does nothing in vain . . . ‘for Nature is pleased with simplicity and affects not the pomp of superfluous causes’. Leibniz hypothesized that the actual world obeys simple laws because God’s taste for simplicity influenced his decision about which world to actualize.
 The tragedy of the Western mind, described by Koyré, is a direct consequence of the stark Cartesian division between mind and world. We discovered the ‘certain principles of physical reality’, said Descartes, ‘not by the prejudices of the senses, but by the light of reason, and which thus possess so great evidence that we cannot doubt of their truth’. Since the real, or that which actually exists external to ourselves, was in his view only that which could be represented in the quantitative terms of mathematics, Descartes concludes that all quantitative aspects of reality could be traced to the deceitfulness of the senses.
 The most fundamental aspect of the Western intellectual tradition is the assumption that there is a fundamental division between the material and the immaterial world or between the realm of matter and the realm of pure mind or spirit. The metaphysical frame-work based on this assumption is known as ontological dualism.  As the word dual implies, the framework is predicated on an ontology, or a conception of the nature of God or Being, that assumes reality has two distinct and separable dimensions. The concept of Being as continuous, immutable, and having a prior or separate existence from the world of change dates from the ancient Greek philosopher Parmenides. The same qualities were associated with the God of the Judeo-Christian tradition, and they were considerably amplified by the role played in theology by Platonic and Neoplatonic philosophy.
 Nicolas Copernicus, Galileo, Johannes Kepler, and Isaac Newton were all inheritors of a cultural tradition in which ontological dualism was a primary article of faith. Hence the idealization of the mathematical ideal as a source of communion with God, which dates from Pythagoras, provided a metaphysical foundation for the emerging natural sciences. This explains why, the creators of classical physics believed that doing physics was a form of communion with the geometrical and mathematical form’s resident in the perfect mind of God. This view would survive in a modified form in what is now known as Einsteinian epistemology and accounts in no small part for the reluctance of many physicists to accept the epistemology associated with the Copenhagen Interpretation.
 At the beginning of the nineteenth century, Pierre-Sinon LaPlace, along with a number of other French mathematicians, advanced the view that the science of mechanics constituted a complete view of nature. Since this science, by observing its epistemology, had revealed itself to be the fundamental science, the hypothesis of God was, they concluded, entirely unnecessary.
 LaPlace is recognized for eliminating not only the theological component of classical physics but the ‘entire metaphysical component’ as well’. The epistemology of science requires, he said, that we proceed by inductive generalizations from observed facts to hypotheses that are ‘tested by observed conformity of the phenomena’. What was unique about LaPlace’s view of hypotheses was his insistence that we cannot attribute reality to them. Although concepts like force, mass, motion, cause, and laws are obviously present in classical physics, they exist in LaPlace’s view only as quantities. Physics is concerned, he argued, with quantities that we associate as a matter of convenience with concepts, and the truths about nature are only the quantities.
 As this view of hypotheses and the truths of nature as quantities were extended in the nineteenth century to a mathematical description of phenomena like heat, light, electricity, and magnetism. LaPlace’s assumptions about the actual character of scientific truths seemed correct. This progress suggested that if we could remove all thoughts about the ‘nature of’ or the ‘source of’ phenomena, the pursuit of strictly quantitative concepts would bring us to a complete description of all aspects of physical reality. Subsequently, figures like Comte, Kirchhoff, Hertz, and Poincaré developed a program for the study of nature hat was quite different from that of the original creators of classical physics.
 The seventeenth-century view of physics as a philosophy of nature or as natural philosophy was displaced by the view of physics as an autonomous science that was ‘the science of nature’. This view, which was premised on the doctrine of positivism, promised to subsume all of the nature with a mathematical analysis of entities in motion and claimed that the true understanding of nature was revealed only in the mathematical description. Since the doctrine of positivism assumes that the knowledge we call physics resides only in the mathematical formalism of physical theory, it disallows the prospect that the vision of physical reality revealed in physical theory can have any other meaning. In the history of science, the irony is that positivism, which was intended to banish metaphysical concerns from the domain of science, served to perpetuate a seventeenth-century metaphysical assumption about the relationship between physical reality and physical theory.
 Epistemology since Hume and Kant has drawn back from this theological underpinning. Indeed, the very idea that nature is simple (or uniform) has come in for a critique. The view has taken hold that a preference for simple and parsimonious hypotheses is purely methodological: It is constitutive of the attitude we call ‘scientific’ and makes no substantive assumption about the way the world is.
 A variety of otherwise diverse twentieth-century philosophers of science have attempted, in different ways, to flesh out this position. Two examples must suffice here: Hesse (1969) as, for summaries of other proposals. Popper (1959) holds that scientists should prefer highly falsifiable (improbable) theories: He tries to show that simpler theories are more falsifiable, also Quine (1966), in contrast, sees a virtue in theories that are highly probable, he argues for a general connection between simplicity and high probability.
 Both these proposals are global. They attempt to explain why simplicity should be part of the scientific method in a way that spans all scientific subject matters. No assumption about the details of any particular scientific problem serves as a premiss in Popper’s or Quine’s arguments.
 Newton and Leibniz thought that the justification of parsimony and simplicity flows from the hand of God: Popper and Quine try to justify these methodologically median of importance is without assuming anything substantive about the way the world is. In spite of these differences in approach, they have something in common. They assume that all users of parsimony and simplicity in the separate sciences can be encompassed in a single justifying argument. That recent developments in confirmation theory suggest that this assumption should be scrutinized. Good (1983) and Rosenkrantz (1977) has emphasized the role of auxiliary assumptions in mediating the connection between hypotheses and observations. Whether a hypothesis is well supported by some observations, or whether one hypothesis is better supported than another by those observations, crucially depends on empirical background assumptions about the inference problem here. The same view applies to the idea of prior probability (or, prior plausibility). In of a single hypo-physical science if chosen as an alternative to another even though they are equally supported by current observations, this must be due to an empirical background assumption.
 Principles of parsimony and simplicity mediate the epistemic connection between hypotheses and observations. Perhaps these principles are able to do this because they are surrogates for an empirical background theory. It is not that there is one background theory presupposed by every appeal to parsimony; This has the quantifier order backwards. Rather, the suggestion is that each parsimony argument is justified only to each degree that it reflects an empirical background theory about the subjective matter. On this theory is brought out into the open, but the principle of parsimony is entirely dispensable (Sober, 1988).
 This ‘local’ approach to the principles of parsimony and simplicity resurrects the idea that they make sense only if the world is one way rather than another. It rejects the idea that these maxims are purely methodological. How defensible this point of view is, will depend on detailed case studies of scientific hypothesis evaluation and on further developments in the theory of scientific inference.
 It is usually not found of one and the same that, an inference is a (perhaps very complex) act of thought by virtue of which act (1) I pass from a set of one or more propositions or statements to a proposition or statement and (2) it appears that the latter are true if the former is or are. This psychological characterization has occurred over a wider summation of literature under more lesser than inessential variations. Desiring a better characterization of inference is natural. Yet attempts to do so by constructing a fuller psychological explanation fail to comprehend the grounds on which inference will be objectively valid-A point elaborately made by Gottlob Frége. Attempts to understand the nature of inference through the device of the representation of inference by formal-logical calculations or derivations better (1) leave ‘us’ puzzled about the relation of formal-logical derivations to the informal inferences they are supposedly to represent or reconstruct, and (2) leaves ‘us’ worried about the sense of such formal derivations. Are these derivations inference? Are not informal inferences needed in order to apply the rules governing the constructions of formal derivations (inferring that this operation is an application of that formal rule)? These are concerns cultivated by, for example, Wittgenstein.
 Coming up with an adequate characterization of inference-and even working out what would count as a very adequate characterization here  is demandingly by no means nearly some resolved philosophical problem.
 The rule of inference, as for raised by Lewis Carroll, the Zeno-like problem of how a ‘proof’ ever gets started. Suppose I have as premises (i) ‘p’ and (ii) p ➝ q. Can I infer ‘q’? Only, it seems, if I am sure of (iii) (p & p ➝q) ➝ q. Can I then infer ‘q’? Only, it seems, if I am sure that (iv) (p & p ➝ q & (p & p ➝ q) ➝ q) ➝ q. For each new axiom (N) I need a further axiom (N + 1) telling me that the set so far implies ‘q’, and the regress never stops. The usual solution is to treat a system as containing not only axioms, but also rules of inference, allowing movement from the axioms. The rule ‘modus ponens’ allow ‘us’ to pass from the first premise to ‘q’. Carroll’s puzzle shows that distinguishing two theoretical categories is essential, although there may be choice about which theses to put in which category.
 Traditionally, a proposition that is not a ‘conditional’, as with the ‘affirmative’ and ‘negative’, modern opinion is wary of the distinction, since what appears categorical may vary with the choice of a primitive vocabulary and notation. Apparently categorical propositions may also turn out to be disguised conditionals: ‘X’ is intelligent (categorical?) Equivalent, if ‘X’ is given a range of tasks, she does them better than many people (conditional?). The problem is not merely one of classification, since deep metaphysical questions arise when facts that seem to be categorical and therefore solid, come to seem by contrast conditional, or purely hypothetical or potential.
 Its condition of some classified necessity is so proven sufficient that if ‘p’ is a necessary condition of ‘q’, then ‘q’ cannot be true unless ‘p’; is true? If ‘p’ is a sufficient condition, thus steering well is a necessary condition of driving in a satisfactory manner, but it is not sufficient, for one can steer well but drive badly for other reasons. Confusion may result if the distinction is not heeded. For example, the statement that ‘A’ causes ‘B’ may be interpreted to mean that ‘A’ is itself a sufficient condition for ‘B’, or that it is only a necessary condition fort ‘B’, or perhaps a necessary parts of a total sufficient condition. Lists of conditions to be met for satisfying some administrative or legal requirement frequently attempt to give individually necessary and jointly sufficient sets of conditions.
 What is more, that if any proposition of the form ‘if p then q’. The condition hypothesized, ‘p’. Is called the antecedent of the conditionals, and ‘q’, the consequent? Various kinds of conditional have been distinguished.  Its weakest is that of ‘material implication’, merely telling that either ‘not-p’, or ‘q’. Stronger conditionals include elements of ‘modality’, corresponding to the thought that ‘if p is truer then q must be true’. Ordinary language is very flexible in its use of the conditional form, and there is controversy whether conditionals are better treated semantically,  yielding differently finds of conditionals with different meanings, or pragmatically, in which case there should be one basic meaning with surface differences arising from other implicatures.
 It follows from the definition of ‘strict implication’ that a necessary proposition is strictly implied by any proposition, and that an impossible proposition strictly implies any proposition. If strict implication corresponds to ‘q follows from p’, then this means that a necessary proposition follows from anything at all, and anything at all follows from an impossible proposition. This is a problem if we wish to distinguish between valid and invalid arguments with necessary conclusions or impossible premises.
 The Humean problem of induction is that if we would suppose that there is some property ‘A’ concerning and observational or an experimental situation, and that out of a large number of observed instances of ‘A’, some fraction m/n (possibly equal to 1) has also been instances of some logically independent property ‘B’. Suppose further that the background proportionate circumstances not specified in these descriptions has been varied to a substantial degree and that there is no collateral information available concerning the frequency of ‘B’s’ among ‘A’s or concerning causal or nomologically connections between instances of ‘A’ and instances of ‘B’.
 In this situation, an ‘enumerative’ or ‘instantial’ induction inference would move rights from the premise, that m/n of observed ‘A’s’ are ‘B’s’ to the conclusion that approximately m/n of all ‘A’s’ are ‘B’s. (The usual probability qualification will be assumed to apply to the inference, rather than being part of the conclusion.) Here the class of ‘A’s’ should be taken to include not only unobserved ‘A’s’ and future ‘A’s’, but also possible or hypothetical ‘A’s’ (an alternative conclusion would concern the probability or likelihood of the adjacently observed ‘A’ being a ‘B’).
 The traditional or Humean problem of induction, often referred to simply as ‘the problem of induction’, is the problem of whether and why inferences that fit this schema should be considered rationally acceptable or justified from an epistemic or cognitive standpoint, i.e., whether and why reasoning in this way is likely to lead to true claims about the world. Is there any sort of argument or rationale that can be offered for thinking that conclusions reached in this way are likely to be true in the corresponding premisses is true  ‒or even that their chances of truth are significantly enhanced?
 Hume’s discussion of this issue deals explicitly only with cases where all observed ‘A’s’ are ‘B’s’ and his argument applies just as well to the more general case. His conclusion is entirely negative and sceptical: Inductive inferences are not rationally justified, but are instead the result of an essentially a-rational process, custom or habit. Hume (1711-76) challenges the proponent of induction to supply a cogent line of reasoning that leads from an inductive premise to the corresponding conclusion and offers an extremely influential argument in the form of a dilemma (a few times referred to as ‘Hume’s fork’), that either our actions are determined, in which case we are not responsible for them, or they are the result of random events, under which case we are also not responsible for them.
 Such reasoning would, he argues, have to be either deductively demonstrative reasoning in the concerning relations of ideas or ‘experimental’, i.e., empirical, that reasoning concerning matters of fact or existence. It cannot be the former, because all demonstrative reasoning relies on the avoidance of contradiction, and it is not a contradiction to suppose that ‘the course of nature may change’, that an order that was observed in the past and not of its continuing against the future: But it cannot be, as the latter, since any empirical argument would appeal to the success of such reasoning about an experience, and the justifiability of generalizing from experience are precisely what is at issue-so that any such appeal would be question-begging. Hence, Hume concludes that there can be no such reasoning (1748).
 An alternative version of the problem may be obtained by formulating it with reference to the so-called Principle of Induction, which says roughly that the future will resemble the past or, somewhat better, that unobserved cases will resemble observed cases. An inductive argument may be viewed as enthymematic, with this principle serving as a supposed premiss, in which case the issue is obviously how such a premiss can be justified. Hume’s argument is then that no such justification is possible: The principle cannot be justified a prior because having possession of been true in experiences without obviously begging the question is not contradictory to have possession of been true in experiences without obviously begging the question.
 The predominant recent responses to the problem of induction, at least in the analytic tradition, in effect accept the main conclusion of Hume’s argument, namely, that inductive inferences cannot be justified in the sense of showing that the conclusion of such an inference is likely to be true if the premise is true, and thus attempt to find another sort of justification for induction. Such responses fall into two main categories: (i) Pragmatic justifications or ‘vindications’ of induction, mainly developed by Hans Reichenbach (1891-1953), and (ii) ordinary language justifications of induction, whose most important proponent is Frederick, Peter Strawson (1919-). In contrast, some philosophers still attempt to reject Hume’s dilemma by arguing either (iii) That, contrary to appearances, induction can be inductively justified without vicious circularity, or (iv) that an anticipatory justification of induction is possible after all. In that:
   (1) Reichenbach’s view is that induction is best regarded, not as a form of inference, but rather as a ‘method’ for arriving at posits regarding, i.e., the proportion of ‘A’s’ remain additionally of ‘B’s’. Such a posit is not a claim asserted to be true, but is instead an intellectual wager analogous to a bet made by a gambler. Understood in this way, the inductive method says that one should posit that the observed proportion is, within some measure of an approximation, the true proportion and then continually correct that initial posit as new information comes in.
 The gambler’s bet is normally an ‘appraised posit’, i.e., he knows the chances or odds that the outcome on which he bets will actually occur. In contrast, the inductive bet is a ‘blind posit’: We do not know the chances that it will succeed or even that success is that it will succeed or even that success is possible. What we are gambling on when we make such a bet is the value of a certain proportion in the independent world, which Reichenbach construes as the limit of the observed proportion as the number of cases increases to infinity. Nevertheless, we have no way of knowing that there are even such a limit, and no way of knowing that the proportion of ‘A’s’ are in addition of ‘B’s’ converges in the end on some stable value than varying at random. If we cannot know that this limit exists, then we obviously cannot know that we have any definite chance of finding it.
 What we can know, according to Reichenbach, is that ‘if’ there is a truth of this sort to be found, the inductive method will eventually find it’. That this is so is an analytic consequence of Reichenbach’s account of what it is for such a limit to exist. The only way that the inductive method of making an initial posit and then refining it in light of new observations can fail eventually to arrive at the true proportion is if the series of observed proportions never converges on any stable value, which means that there is no truth to be found pertaining the proportion of ‘A’s additionally constitute ‘B’s’. Thus, induction is justified, not by showing that it will succeed or indeed, that it has any definite likelihood of success, but only by showing that it will succeed if success is possible. Reichenbach’s claim is that no more than this can be established for any method, and hence that induction gives ‘us’ our best chance for success, our best gamble in a situation where there is no alternative to gambling.
 This pragmatic response to the problem of induction faces several serious problems. First, there are indefinitely many other ‘methods’ for arriving at posits for which the same sort of defence can be given-methods that yield the same results as the inductive method over time but differ arbitrarily before long. Despite the efforts of others, it is unclear that there is any satisfactory way to exclude such alternatives, in order to avoid the result that any arbitrarily chosen short-term posit is just as reasonable as the inductive posit. Second, even if there is a truth of the requisite sort to be found, the inductive method is only guaranteed to find it or even to come within any specifiable distance of it in the indefinite long run. All the same, any actual application of inductive results always takes place in the presence to the future eventful states in making the relevance of the pragmatic justification to actual practice uncertainly. Third, and most important, it needs to be emphasized that Reichenbach’s response to the problem simply accepts the claim of the Humean sceptic that an inductive premise never provides the slightest reason for thinking that the corresponding inductive conclusion is true. Reichenbach himself is quite candid on this point, but this does not alleviate the intuitive implausibility of saying that we have no more reason for thinking that our scientific and commonsense conclusions that result in the induction of it ‘ . . .  is true’ than, to use Reichenbach’s own analogy (1949), a blind man wandering in the mountains who feels an apparent trail with his stick has for thinking that following it will lead him to safety.
 An approach to induction resembling Reichenbach’s claiming in that those particular inductive conclusions are posits or conjectures, than the conclusions of cogent inferences, is offered by Popper. However, Popper’s view is even more overtly sceptical: It amounts to saying that all that can ever be said in favour of the truth of an inductive claim is that the claim has been tested and not yet been shown to be false.
   (2) The ordinary language response to the problem of induction has been advocated by many philosophers, none the less, Strawson claims that the question whether induction is justified or reasonable makes sense only if it tacitly involves the demand that inductive reasoning meet the standards appropriate to deductive reasoning, i.e., that the inductive conclusions are shown to follow deductively from the inductive assumption. Such a demand cannot, of course, be met, but only because it is illegitimate: Inductive and deductive reasons are simply fundamentally different kinds of reasoning, each possessing its own autonomous standards, and there is no reason to demand or expect that one of these kinds meet the standards of the other. Whereas, if induction is assessed by inductive standards, the only ones that are appropriate, then it is obviously justified.
 The problem here is to understand to what this allegedly obvious justification of an induction amount. In his main discussion of the point (1952), Strawson claims that it is an analytic true statement that believing it a conclusion for which there is strong evidence is reasonable and an analytic truth that inductive evidence of the sort captured by the schema presented earlier constitutes strong evidence for the corresponding inductive conclusion, thus, apparently yielding the analytic conclusion that believing it a conclusion for which there is inductive evidence is reasonable. Nevertheless, he also admits, indeed insists, that the claim that inductive conclusions will be true in the future is contingent, empirical, and may turn out to be false (1952). Thus, the notion of reasonable belief and the correlative notion of strong evidence must apparently be understood in ways that have nothing to do with likelihood of truth, presumably by appeal to the standard of reasonableness and strength of evidence that are accepted by the community and are embodied in ordinary usage.
 Understood in this way, Strawson’s response to the problem of inductive reasoning does not speak to the central issue raised by Humean scepticism: The issue of whether the conclusions of inductive arguments are likely to be true. It amounts to saying merely that if we reason in this way, we can correctly call ourselves ‘reasonable’ and our evidence ‘strong’, according to our accepted community standards. Nevertheless, to the undersealing of issue of wether following these standards is a good way to find the truth, the ordinary language response appears to have nothing to say.
   (3) The main attempts to show that induction can be justified inductively have concentrated on showing that such as a defence can avoid circularity. Skyrms (1975) formulate, perhaps the clearest version of this general strategy. The basic idea is to distinguish different levels of inductive argument: A first level in which induction is applied to things other than arguments: A second level in which it is applied to arguments at the first level, arguing that they have been observed to succeed so far and hence are likely to succeed in general: A third level in which it is applied in the same way to arguments at the second level, and so on. Circularity is allegedly avoided by treating each of these levels as autonomous and justifying the argument at each level by appeal to an argument at the next level.
 One problem with this sort of move is that even if circularity is avoided, the movement to higher and higher levels will clearly eventually fail simply for lack of evidence: A level will reach at which there have been enough successful inductive arguments to provide a basis for inductive justification at the next higher level, and if this is so, then the whole series of justifications collapses. A more fundamental difficulty is that the epistemological significance of the distinction between levels is obscure. If the issue is whether reasoning in accord with the original schema offered above ever provides a good reason for thinking that the conclusion is likely to be true, then it still seems question-begging, even if not flatly circular, to answer this question by appeal to anther argument of the same form.
   (4) The idea that induction can be justified on a pure priori basis is in one way the most natural response of all: It alone treats an inductive argument as an independently cogent piece of reasoning whose conclusion can be seen rationally to follow, although perhaps only with probability from its premise. Such an approach has, however, only rarely been advocated (Russell, 19132 and BonJour, 1986), and is widely thought to be clearly and demonstrably hopeless.
 Many on the reasons for this pessimistic view depend on general epistemological theses about the possible or nature of anticipatory cognition. Thus if, as Quine alleges, there is no a prior justification of any kind, then obviously a prior justification for induction is ruled out. Or if, as more moderate empiricists have in claiming some preexistent knowledge should be analytic, then again a prevenient justification for induction seems to be precluded, since the claim that if an inductive premise ids truer, then the conclusion is likely to be true does not fit the standard conceptions of ‘analyticity’. A consideration of these matters is beyond the scope of the present spoken exchange.
 There are, however, two more specific and quite influential reasons for thinking that an early approach is impossible that can be briefly considered, first, there is the assumption, originating in Hume, but since adopted by very many of others, that a move forward in  the defence of induction would have to involve ‘turning induction into deduction’, i.e., showing, per impossible, that the inductive conclusion follows deductively from the premise, so that it is a formal contradiction to accept the latter and deny the former. However, it is unclear why a prior approach need be committed to anything this strong. It would be enough if it could be argued that it is deductively unlikely that such a premise is true and corresponding conclusion false.
 Second, Reichenbach defends his view that pragmatic justification is the best that is possible by pointing out that a completely chaotic world in which there is simply not true conclusion to be found as to the proportion of ‘A’s’ in addition that occurs of, but B’s’ is neither impossible nor unlikely from a purely a prior standpoint, the suggestion being that therefore there can be no a prior reason for thinking that such a conclusion is true. Nevertheless, there is still a substring wayin laying that a chaotic world is a prior neither impossible nor unlikely without any further evidence does not show that such a world os not a prior unlikely and a world containing such-and-such regularity might anticipatorially be somewhat likely in relation to an occurrence of a long-run patten of evidence in which a certain stable proportion of observed ‘A’s’ are ‘B’s’ ~. An occurrence, it might be claimed, that would be highly unlikely in a chaotic world (BonJour, 1986).
 Goodman’s ‘new riddle of induction’ purports that we suppose that before some specific time ’t’ (perhaps the year 2000) we observe a larger number of emeralds (property A) and find them all to be green (property B). We proceed to reason inductively and conclude that all emeralds are green Goodman points out, however, that we could have drawn a quite different conclusion from the same evidence. If we define the term ‘grue’ to mean ‘green if examined before ’t’ and blue examined after t ʹ, then all of our observed emeralds will also be gruing.  A parallel inductive argument will yield the conclusion that all emeralds are gruing, and hence that all those examined after the year 2000 will be blue. Presumably the first of these concisions is genuinely supported by our observations and the second is not.  Nevertheless, the problem is to say why this is so and to impose some further restriction upon inductive reasoning that will permit the first argument and exclude the second.
 The obvious alternative suggestion is that ‘grue.  Similar predicates do not correspond to genuine, purely qualitative properties in the way that ‘green’ and ‘blueness’ does, and that this is why inductive arguments involving them are unacceptable. Goodman, however, claims to be unable to make clear sense of this suggestion, pointing out that the relations of formal desirability are perfectly symmetrical: Grue’ may be defined in terms if, ‘green’ and ‘blue’, but ‘green’ an equally well be defined in terms of ‘grue’ and ‘green’ (blue if examined before ‘t’ and green if examined after ‘t’).
 The ‘grued, paradoxes’ demonstrate the importance of categorization, in that sometimes it is itemized as ‘gruing’, if examined of a presence to the future, before future time ‘t’ and ‘green’, or not so examined and ‘blue’. Even though all emeralds in our evidence class grue, we ought must infer that all emeralds are gruing. For ‘grue’ is unprojectible, and cannot transmit credibility form known to unknown cases. Only projectable predicates are right for induction. Goodman considers entrenchment the key to projectibility having a long history of successful protection, ‘grue’ is entrenched, lacking such a history, ‘grue’ is not. A hypothesis is projectable, Goodman suggests, only if its predicates (or suitable related ones) are much better entrenched than its rivalrous past successes that do not assume future ones. Induction remains a risky business. The rationale for favouring entrenched predicates is pragmatic. Of the possible projections from our evidence class, the one that fits with past practices enables ‘us’ to utilize our cognitive resources best. Its prospects of being true are worse than its competitors’ and its cognitive utility is greater.
 So, to a better understanding of induction we should then term is most widely used for any process of reasoning that takes ‘us’ from empirical premises to empirical conclusions supported by the premises, but not deductively entailed by them. Inductive arguments are therefore kinds of applicative arguments, in which something beyond the content of the premise is inferred as probable or supported by them. Induction is, however, commonly distinguished from arguments to theoretical explanations, which share this applicative character, by being confined to inferences in which he conclusion involves the same properties or relations as the premises. The central example is induction by simple enumeration, where from premises telling that Fa, Fb, Fc . . . ‘where a, b, c’s, are all of some kind ‘G’, it is inferred that G’s from outside the sample, such as future G’s, will be ‘F’, or perhaps that all G’s are ‘F’. In this, which and the other persons deceive them, children may infer that everyone is a deceiver: Different, but similar inferences of a property by some object to the same object’s future possession of the same property, or from the constancy of some law-like pattern in events and states of affairs ti its future constancy. All objects we know of attract each other with a force inversely proportional to the square of the distance between them, so perhaps they all do so, and will always do so.
 The rational basis of any inference was challenged by Hume, who believed that induction presupposed belie in the uniformity of nature, but that this belief has no defence in reason, and merely reflected a habit or custom of the mind. Hume was not therefore sceptical about the role of reason in either explaining it or justifying it. Trying to answer Hume and to show that there is something rationally compelling about the inference referred to as the problem of induction. It is widely recognized that any rational defence of induction will have to partition well-behaved properties for which the inference is plausible (often called projectable properties) from badly behaved ones, for which it is not. It is also recognized that actual inductive habits are more complex than those of similar enumeration, and that both common sense and science pay attention to such giving factors as variations within the sample giving ‘us’ the evidence, the application of ancillary beliefs about the order of nature, and so on.
 Nevertheless, the fundamental problem remains that ant experience condition by application show ‘us’ only events occurring within a very restricted part of a vast spatial and temporal order about which we then come to believe things.
 Uncompounded by its belonging of a confirmation theory finding of the measure to which evidence supports a theory fully formalized confirmation theory would dictate the degree of confidence that a rational investigator might have in a theory, given some-body of evidence. The grandfather of confirmation theory is Gottfried Leibniz (1646-1718), who believed that a logically transparent language of science would be able to resolve all disputes. In the 20th century a fully formal confirmation theory was a main goal of the logical positivist, since without it the central concept of verification by empirical evidence itself remains distressingly unscientific. The principal developments were due to Rudolf Carnap (1891-1970), culminating in his ‘Logical Foundations of Probability’ (1950). Carnap’s idea was that the measure necessitated would be the proportion of logically possible states of affairs in which the theory and the evidence both hold, compared ti the number in which the evidence itself holds that the probability of a preposition, relative to some evidence, is a proportion of the range of possibilities under which the proposition is true, compared to the total range of possibilities left by the evidence. The difficulty with the theory lies in identifying sets of possibilities so that they admit of measurement. It therefore demands that we can put a measure on the ‘range’ of possibilities consistent with theory and evidence, compared with the range consistent with the evidence alone.
 Among the obstacles the enterprise meets, is the fact that while evidence covers only a finite range of data, the hypotheses of science may cover an infinite range. In addition, confirmation proves to vary with the language in which the science is couched, and the Carnapian programme has difficulty in separating genuinely confirming variety of evidence from less compelling repetition of the same experiment. Confirmation also proved to be susceptible to acute paradoxes. Finally, scientific judgement seems to depend on such intangible factors as the problems facing rival theories, and most workers have come to stress instead the historically situated scene of what would appear as a plausible distinction of a scientific knowledge at a given time.
 Arose to the paradox of which when a set of apparent incontrovertible premises is given to unacceptable or contradictory conclusions. To solve a paradox will involve showing either that there is a hidden flaw in the premises, or that the reasoning is erroneous, or that the apparently unacceptable conclusion can, in fact, be tolerated. Paradoxes are therefore important in philosophy, for until one is solved it shows that there is something about our reasoning and our concepts that we do not understand. What is more, and somewhat loosely, a paradox is a compelling argument from unacceptable premises to an unacceptable conclusion: More strictly speaking, a paradox is specified to be a sentence that is true if and only if it is false. A characterized objection lesson of it would be: ‘The displayed sentence is false.’
 Seeing that this sentence is false if true is easy, and true if false, a paradox, in either of the senses distinguished, presents an important philosophical challenger. Epistemologists are especially concerned with various paradoxes having to do with knowledge and belief. In other words, for example, the Knower paradox is an argument that begins with apparently impeccable premisses about the concepts of knowledge and inference and derives an explicit contradiction. The origin of the reasoning is the ‘surprise examination paradox’: A teacher announces that there will be a surprise examination next week. A clever student argues that this is impossible. ‘The test cannot be on Friday, the last day of the week, because it would not be a surprise. We would know the day of the test on Thursday evening. This means we can also rule out Thursday. For after we learn that no test has been given by Wednesday, we would know the test is on Thursday or Friday -and would already know that it s not on Friday and would already know that it is not on Friday by the previous reasoning. The remaining days can be eliminated in the same manner’.
 This puzzle has over a dozen variants. The first was probably invented by the Swedish mathematician Lennard Ekbon in 1943. Although the first few commentators regarded the reverse elimination argument as cogent, every writer on the subject since 1950 agrees that the argument is unsound. The controversy has been over the proper diagnosis of the flaw.
 Initial analyses of the subject’s argument tried to lay the blame on a simple equivocation. Their failure led to more sophisticated diagnoses. The general format has been an assimilation to better-known paradoxes. One tradition casts the surprise examination paradox as a self-referential problem, as fundamentally akin to the Liar, the paradox of the Knower, or Gödel’s incompleteness theorem. That in of itself, says enough that Kaplan and Montague (1960) distilled the following ‘self-referential’ paradox, the Knower. Consider the sentence:
(S) The negation of this sentence is known (to be true).
Suppose that (S) is true. Then its negation is known and hence true. However, if its negation is true, then (S) must be false. Therefore (s) is false, or what is the name, the negation of (S) is true.
 This paradox and its accompanying reasoning are strongly reminiscent of the Lair Paradox that (in one version) begins by considering a sentence ‘This sentence is false’ and derives a contradiction. Versions of both arguments using axiomatic formulations of arithmetic and Gödel-numbers to achieve the effect of self-reference yields important meta-theorems about what can be expressed in such systems. Roughly these are to the effect that no predicates definable in the formalized arithmetic can have the properties we demand of truth (Tarski’s Theorem) or of knowledge (Montague, 1963).
 These meta-theorems still leave ‘us; with the problem that if we suppose that we add of these formalized languages predicates intended to express the concept of knowledge (or truth) and inference-as one mighty does if a logic of these concepts is desired. Then the sentence expressing the leading principles of the Knower Paradox will be true.
Explicitly, the assumption about knowledge and inferences are:
  (1) If sentences ‘A’ are known, then ‘a.’
  (2) (1) is known?
  (3) If ‘B’ is correctly inferred from ‘A’, and ‘A’ is known, then ‘B’ id known.
To give an absolutely explicit t derivation of the paradox by applying these principles to (S), we must add (contingent) assumptions to the effect that certain inferences have been done. Still, as we go through the argument of the Knower, these inferences are done. Even if we can somehow restrict such principles and construct a consistent formal logic of knowledge and inference, the paradoxical argument as expressed in the natural language still demands some explanation.
 The usual proposals for dealing with the Liar often have their analogues for the Knower, e.g., that there is something wrong with a self-reference or that knowledge (or truth) is properly a predicate of propositions and not of sentences. The relies that show that some of these are not adequate are often parallel to those for the Liar paradox. In addition, on e c an try here what seems to be an adequate solution for the Surprise Examination Paradox, namely the observation that ‘new knowledge can drive out knowledge’, but this does not seem to work on the Knower (Anderson, 1983).
 There are a number of paradoxes of the Liar family. The simplest example is the sentence ‘This sentence is false’, which must be false if it is true, and true if it is false. One suggestion is that the sentence fails to say anything, but sentences that fail to say anything are at least not true. In fact case, we consider to sentences ‘This sentence is not true’, which, if it fails to say anything is not true, and hence (this kind of reasoning is sometimes called the strengthened Liar). Other versions of the Liar introduce pairs of sentences, as in a slogan on the front of a T-shirt saying ‘This sentence on the back of this T-shirt is false’, and one on the back saying ‘The sentence on the front of this T-shirt is true’. It is clear that each sentence individually is well formed, and was it not for the other, might have said something true. So any attempts to dismiss the paradox by sating that the sentence involved are meaningless will face problems.
 Even so, the two approaches that have some hope of adequately dealing with this paradox is ‘hierarchy’ solutions and ‘truth-value gap’ solutions. According to the first, knowledge is structured into ‘levels’. It is argued that there be one-coherent notion expressed by the verb; knows’, but rather a whole series of notions: knows0. knows, and so on (perhaps into transfinite), stated ion terms of predicate expressing such ‘ramified’ concepts and properly restricted, (1)-(3) lead to no contradictions. The main objections to this procedure are that the meaning of these levels has not been adequately explained and that the idea of such subscripts, even implicit, in a natural language is highly counterintuitive the ‘truth-value gap’ solution takes sentences such as (S) to lack truth-value. They are neither true nor false, but they do not express propositions. This defeats a crucial step in the reasoning used in the derivation of the paradoxes. Kripler (1986) has developed this approach in connection with the Liar and Asher and Kamp (1986) has worked out some details of a parallel solution to the Knower. The principal objection is that ‘strengthened’ or ‘super’ versions of the paradoxes tend to reappear when the solution itself is stated.
 Since the paradoxical deduction uses only the properties (1)-(3) and since the argument is formally valid, any notions that satisfy these conditions will lead to a paradox. Thus, Grim (1988) notes that this may be read as ‘is known by an omniscient God’ and concludes that there is no coherent single notion of omniscience. Thomason (1980) observes that with some different conditions, analogous reasoning about belief can lead to paradoxical consequence.
 Overall, it looks as if we should conclude that knowledge and truth are ultimately intrinsically ‘stratified’ concepts. It would seem that wee must simply accept the fact that these (and similar) concepts cannot be assigned of any-one fixed, finite or infinite. Still, the meaning of this idea certainly needs further clarification.
 Its paradox arises when a set of apparently incontrovertible premises gives unacceptable or contradictory conclusions, to solve a paradox will involve showing either that there is a hidden flaw in the premises, or that the reasoning is erroneous, or that the apparently unacceptable conclusion can, in fact, be tolerated. Paradoxes are therefore important in philosophy, for until one is solved its show that there is something about our reasoning and our concepts that we do not understand. Famous families of paradoxes include the ‘semantic paradoxes’ and ‘Zeno’s paradoxes. Art the beginning of the 20th century, paradox and other set-theoretical paradoxes led to the complete overhaul of the foundations of set theory, while the ’Sorites paradox’ has lead to the investigations of the semantics of vagueness and fuzzy logics.
 It is, however, to what extent can analysis be informative? This is the question that gives a riser to what philosophers has traditionally called ‘the’ paradox of analysis. Thus, consider the following proposition:
 (1) To be an instance of knowledge is to be an instance of justified true belief not essentially grounded in any falsehood.
(1) if true, illustrates an important type of philosophical analysis. For convenience of exposition, I will assume (1) is a correct analysis. The paradox arises from the fact that if the concept of justified true belief not been essentially grounded in any falsification is the analysand of the concept of knowledge, it would seem that they are the same concept and hence that:
(2) To be an instance of knowledge is to be as an instance of.
knowledge and would have to be the same propositions as (1). But then how can (1) be informative when (2) is not? This is what is called the first paradox of analysis. Classical writings’ on analysis suggests a second paradoxical analysis (Moore, 1942).
 (3) An analysis of the concept of being a brother is that to be a
brother is to be a male sibling. If (3) is true, it would seem that the concept of being a brother would have to be the same concept as the concept of being a male sibling and tat:
 (4) An analysis of the concept of being a brother is that to be a brother is to be a brother
would also have to be true and in fact, would have to be the same proposition as (3?). Yet (3) is true and (4) is false.
 Both these paradoxes rest upon the assumptions that analysis is a relation between concepts, than one involving entity of other sorts, such as linguistic expressions, and tat in a true analysis, analysand and analysandum are the same concept. Both these assumptions are explicit in Moore, but some of Moore’s remarks hint at a solution to that of another statement of an analysis is a statement partly about the concept involved and partly about the verbal expressions used to express it. He says he thinks a solution of this sort is bound to be right, but fails to suggest one because he cannot see a way in which the analysis can be even partly about the expression (Moore, 1942).
  Elsewhere, of such ways, as a solution to the second paradox, to which is explicating (3) as:
 (5) An analysis is given by saying that the verbal expression ‘χ is a brother’ expresses the same concept as is expressed by the conjunction of the verbal expressions ‘χ is male’ when used to express the concept of being male and ‘χ is a sibling’ when used to express the concept of being a sibling. (Ackerman, 1990).
An important point about (5) is as follows. Stripped of its philosophical jargon (‘analysis’, ‘concept’, ‘χ is a  . . . ‘), (5) seems to state the sort of information generally stated in a definition of the verbal expression ‘brother’ in terms of the verbal expressions ‘male’ and ‘sibling’, where this definition is designed to draw upon listeners’ antecedent understanding of the verbal expression ‘male’ and ‘sibling’, and thus, to tell listeners what the verbal expression ‘brother’ really means, instead of merely providing the information that two verbal expressions are synonymous without specifying the meaning of either one. Thus, its solution to the second paradox seems to make the sort of analysis tat gives rise to this paradox matter of specifying the meaning of a verbal expression in terms of separate verbal expressions already understood and saying how the meanings of these separate, already-understood verbal expressions are combined. This corresponds to Moore’s intuitive requirement that an analysis should both specify the constituent concepts of the analysandum and tell how they are combined, but is this all there is to philosophical analysis?
 To answer this question, we must note that, in addition too there being two paradoxes of analysis, there is two types of analyses that are relevant here. (There are also other types of analysis, such as reformatory analysis, where the analysands are intended to improve on and replace the analysandum. But since reformatory analysis involves no commitment to conceptual identity between analysand and analysandum, reformatory analysis does not generate a paradox of analysis and so will not concern ‘us’ here.) One way to recognize the difference between the two types of analysis concerning ‘us’ here is to focus on the difference between the two paradoxes. This can be done by means of the Frége-inspired sense-individuation condition, which is the condition that two expressions have the same sense if and only if they can be interchangeably ‘salva veritate’ whenever used in propositional attitude context. If the expressions for the analysands and the analysandum in (1) met this condition, (1) and (2) would not raise the first paradox, but the second paradox arises regardless of whether the expression for the analysand and the analysandum meet this condition. The second paradox is a matter of the failure of such expressions to be interchangeable salva veritate in sentences involving such contexts as ‘an analysis is given thereof. Thus, a solution (such as the one offered) that is aimed only at such contexts can solve the second paradox. This is clearly false for the first paradox, however, which will apply to all pairs of propositions expressed by sentences in which expressions for pairs of analysands and anslysantia raising the first paradox is interchangeable. For example, consider the following proposition:
 (6) Mary knows that some cats tail.
It is possible for John to believe (6) without believing:
 (7) Mary has justified true belief, not essentially grounded in any falsehood, that some cats lack tails.
Yet this possibility clearly does not mean that the proposition that Mary knows that some casts lack tails is partly about language.
 One approach to the first paradox is to argue that, despite the apparent epistemic inequivalence of (1) and (2), the concept of justified true belief not essentially grounded in any falsehood is still identical with the concept of knowledge (Sosa, 1983). Another approach is to argue that in the sort of analysis raising the first paradox, the analysand and analysandum is concepts that are different but that bear a special epistemic relation to each other. Elsewhere, the development is such an approach and suggestion that this analysand-analysandum relation has the following facets.
 (a) The analysand and analysandum are necessarily coextensive, i.e., necessarily every instance of one is an instance of the other.
 (b) The analysand and analysandum are knowable theoretical to be coextensive.
 © The analysandum is simpler than the analysands a condition whose necessity is recognized in classical writings on analysis, such as, Langford, 1942.
 (d) The analysand do not have the analysandum as a constituent.
Condition (d) rules out circularity. But since many valuable quasi-analyses are partly circular, e.g., knowledge is justified true belief supported by known reasons not essentially grounded in any falsehood, it seems best to distinguish between full analysis, from that of (d) is a necessary condition, and partial analysis, for which it is not.
These conditions, while necessary, are clearly insufficient. The basic problem is that they apply too many pairs of concepts that do not seem closely enough related epistemologically to count as analysand and analysandum. , such as the concept of being 6 and the concept of the fourth root of 1296. Accordingly, its solution upon what actually seems epistemologically distinctive about analyses of the sort under consideration, which is a certain way they can be justified. This is by the philosophical example-and-counterexample method, which is in a general term that goes as follows. ‘J’ investigates the analysis of K’s concept ‘Q’ (where ‘K’ can but need not be identical to ‘J’ by setting ‘K’ a series of armchair thought experiments, i.e., presenting ‘K’ with a series of simple described hypothetical test cases and asking ‘K’ questions of the form ‘If such-and-such where the case would this count as a case of Q? ‘J’ then contrasts the descriptions of the cases to which; K’ answers affirmatively with the description of the cases to which ‘K’ does not, and ‘J’ generalizes upon these descriptions to arrive at the concepts (if possible not including the analysandum) and their mode of combination that constitute the analysand of K’‘s concept ‘Q’. Since ‘J’ need not be identical with ‘K’, there is no requirement that ‘K’ himself be able to perform this generalization, to recognize its result as correct, or even to understand he analysand that is its result. This is reminiscent of Walton’s observation that one can simply recognize a bird as a swallow without realizing just what feature of the bird (beak, wing configurations, etc.) form the basis of this recognition. (The philosophical significance of this way of recognizing is discussed in Walton, 1972) ‘K’ answers the questions based solely on whether the described hypothetical cases just strike him as cases of ‘Q’. ‘J’ observes certain strictures in formulating the cases and questions. He makes the cases as simple as possible, to minimize the possibility of confusion and to minimize the likelihood that ‘K’ will draw upon his philosophical theories (or quasi-philosophical, a rudimentary notion if he is unsophisticated philosophically) in answering the questions. For this conflicting result, the conflict should ‘other things being equal’ be resolved in favour of the simpler case. ‘J’ makes the series of described cases wide-ranging and varied, with the aim of having it be a complete series, where a series is complete if and only if no case that is omitted in such that, if included, it would change the analysis arrived at. ‘J’ does not, of course, use as a test-case description anything complicated and general enough to express the analysand. There is no requirement that the described hypothetical test cases be formulated only in terms of what can be observed. Moreover, using described hypothetical situations as test cases enables ‘J’ to frame the questions in such a way as to rule out extraneous background assumption to a degree, thus, even if ‘K’ correctly believes that all and only P’s are R’s, the question of whether the concepts of P, R, or both enter the analysand of his concept ‘Q’ can be investigated by asking him such questions as ‘Suppose (even if it seems preposterous to you) that you were to find out that there was a ‘P’ that was not an ‘R’. Would you still consider it a case of Q?
 Taking all this into account, the fifth necessary condition for this sort of analysand-analysandum relations is as follows:
 (e) If ‘S’ is the analysand of ‘Q’, the proposition that necessarily all and only instances of ‘S’ are instances of ‘Q’ can be justified by generalizing from intuition about the correct answers to questions of the sort indicated about a varied and wide-ranging series of simple described hypothetical situations. It so does occur of antinomy, when we are able to argue for, or demonstrate, both a proposition and its contradiction, roughly speaking, a contradiction of a proposition ‘p’ is one that can be expressed in form ‘not-p’, or, if ‘p’ can be expressed in the form ‘not-q’, then a contradiction is one that can be expressed in the form ‘q’. Thus, e.g., if ‘p is 2 + 1 = 4, then      2 + 1 ≠ 4 is the contradictory of ‘p’, for 2 + 1 ≠ 4 can be expressed in the form not (2 + 1 = 4). If ‘p’ is 2 + 1 ≠ 4, then 2 + 1-4 is a contradictory of ‘p’, since 2 + 1 ≠ 4 can be expressed in the form not (2 + 1 = 4). This is, mutually, but contradictory propositions can be expressed in the form, ‘r’, ‘not-r’. The Principle of Contradiction says that mutually contradictory propositions cannot both be true and cannot both be false. Thus, by this principle, since if ‘p’ is true, ‘not-p’ is false, no proposition ‘p’ can be at once true and false (otherwise both ‘p’ and its contradictories would be false?). In particular, for any predicate ‘p’ and object ‘χ’, it cannot be that ‘p’; is at once true of ‘χ’ and false of χ? This is the classical formulation of the principle of contradiction, but it is nonetheless, that wherein, we cannot now fault either demonstrates. We would eventually hope to be able ‘to solve the antinomy’ by managing, through careful thinking and analysis, eventually to fault either or both demonstrations.
 Many paradoxes are as an easy source of antinomies, for example, Zeno gave some famously lets say, logical-cum-mathematical arguments that might be interpreted as demonstrating that motion is impossible. But our eyes as it was, demonstrate motion (exhibit moving things) all the time. Where did Zeno go wrong? Where do our eyes go wrong? If we cannot readily answer at least one of these questions, then we are in antinomy. In the ‘Critique of Pure Reason,’ Kant gave demonstrations of the same kind -in the Zeno example they were obviously not the same kind of both, e.g., that the world has a beginning in time and space, and that the world has no beginning in time or space. He argues that both demonstrations are at fault because they proceed on the basis of ‘pure reason’ unconditioned by sense experience.
 At this point, we display attributes to the theory of experience, as it is not possible to define in an illuminating way, however, we know what experiences are through acquaintances with some of our own, e.g., visual experiences of as afterimage, a feeling of physical nausea or a tactile experience of an abrasive surface (which might be caused by an actual surface -rough or smooth, or which might be part of a dream, or the product of a vivid sensory imagination). The essential feature of experience is it feels a certain way  -that there is something that it is like to have it. We may refer to this feature of an experience as its ‘character’.
 Another core feature of the sorts of experiences with which this may be of a concern, is that they have representational ‘content’. (Unless otherwise indicated, ‘experience’ will be reserved for their ‘contentual representations’.) The most obvious cases of experiences with content are sense experiences of the kind normally involved in perception. We may describe such experiences by mentioning their sensory modalities ad their contents, e.g., a gustatory experience (modality) of chocolate ice cream (content), but do so more commonly by means of perceptual verbs combined with noun phrases specifying their contents, as in ‘Macbeth saw a dagger’. This is, however, ambiguous between the perceptual claim ‘There was a (material) dagger in the world that Macbeth perceived visually’ and ‘Macbeth had a visual experience of a dagger’ (the reading with which we are concerned, as it is afforded by our imagination, or perhaps, experiencing mentally hallucinogenic imagery).
 As in the case of other mental states and events with content, it is important to distinguish between the properties that and experience ‘represents’ and the properties that it ‘possesses’. To talk of the representational properties of an experience is to say something about its content, not to attribute those properties to the experience itself. Like every other experience, a visual; experience of a non-shaped square, of which is a mental event, and it is therefore not itself irregular or is it square, even though it represents those properties. It is, perhaps, fleeting, pleasant or unusual, even though it does not represent those properties. An experience may represent a property that it possesses, and it may even do so in virtue of a rapidly changing (complex) experience representing something as changing rapidly.  However, this is the exception and not the rule.
 Which properties can be [directly] represented in sense experience is subject to debate. Traditionalists include only properties whose presence could not be doubted by a subject having appropriate experiences, e.g., colour and shape in the case of visual experience, and apparent shape, surface texture, hardness, etc., in the case of tactile experience. This view is natural to anyone who has an egocentric, Cartesian perspective in epistemology, and who wishes for pure data in experiences to serve as logically certain foundations for knowledge, especially to the immediate objects of perceptual awareness in or of sense-data, such categorized of colour patches and shapes, which are usually supposed distinct from surfaces of physical objectivity. Qualities of sense-data are supposed to be distinct from physical qualities because their perception is more relative to conditions, more certain, and more immediate, and because sense-data is private and cannot appear other than they are they are objects that change in our perceptual field when conditions of perception change.  Physical objects remain constant.
 Others who do not think that this wish can be satisfied, and who are more impressed with the role of experience in providing animisms with ecologically significant information about the world around them, claim that sense experiences represent properties, characteristic and kinds that are much richer and much more wide-ranging than the traditional sensory qualities. We do not see only colours and shapes, they tell ‘us’, but also earth, water, men, women and fire: We do not smell only odours, but also food and filth. There is no space here to examine the factors relevantly responsible to their choice of situational alternatives. Yet, this suggests that character and content are not really distinct, and there is a close tie between them. For one thing, the relative complexity of the character of sense experience places limitations upon its possible content, e.g., a tactile experience of something touching one’s left ear is just too simple to carry the same amount of content as typically convincing to an every day, visual experience. Moreover, the content of a sense experience of a given character depends on the normal causes of appropriately similar experiences, e.g., the sort of gustatory experience that we have when eating chocolate would be not represented as chocolate unless it was normally caused by chocolate. Granting a contingent ties between the character of an experience and its possible causal origins, once, again follows that its possible content is limited by its character.
 Character and content are none the less irreducibly different, for the following reasons. (a) There are experiences that completely lack content, e.g., certain bodily pleasures. (b) Not every aspect of the character of an experience with content is relevant to that content, e.g., the unpleasantness of an aural experience of chalk squeaking on a board may have no representational significance. © Experiences in different modalities may overlap in content without a parallel overlap in character, e.g., visual and tactile experiences of circularity feel completely different. (d) The content of an experience with a given character may vary according to the background of the subject, e.g., a certain content ‘singing bird’ only after the subject has learned something about birds.
 According to the act/object analysis of experience (which is a special case of the act/object analysis of consciousness), every experience involves an object of experience even if it has no material object. Two main lines of argument may be offered in support of this view, one ‘phenomenological’ and the other ‘semantic’.
 In an outline, the phenomenological argument is as follows. Whenever we have an experience, even if nothing beyond the experience answers to it, we seem to be presented with something through the experience (which is itself diaphanous). The object of the experience is whatever is so presented to ‘us’-is that it is an individual thing, an event, or a state of affairs.
 The semantic argument is that objects of experience are required in order to make sense of certain features of our talk about experience, including, in particular, the following. (i) Simple attributions of experience, e.g., ‘Rod is experiencing an oddity that is not really square but in appearance it seems more than likely a square’, this seems to be relational. (ii) We appear to refer to objects of experience and to attribute properties to them, e.g., ‘The after-image that John experienced was certainly odd’. (iii) We appear to quantify ov er objects of experience, e.g., ‘Macbeth saw something that his wife did not see’.
 The act/object analysis faces several problems concerning the status of objects of experiences. Currently the most common view is that they are sense-data  -private mental entities that actually posses the traditional sensory qualities represented by the experiences of which they are the objects. But the very idea of an essentially private entity is suspect. Moreover, since an experience may apparently represent something as having a determinable property, e.g., redness, without representing it as having any subordinate determinate property, e.g., any specific shade of red, a sense-datum may actually have a determinate property subordinate to it. Even more disturbing is that sense-data may have contradictory properties, since experiences can have contradictory contents. A case in point is the waterfall illusion: If you stare at a waterfall for a minute and then immediately fixate on a nearby rock, you are likely to have an experience of the rock’s moving upward while it remains in the same place. The sense-data theorist must either deny that there are such experiences or admit contradictory objects.
 These problems can be avoided by treating objects of experience as properties. This, however, fails to do justice to the appearances, for experience seems not to present ‘us’ with properties embodied in individuals. The view that objects of experience is Meinongian objects accommodate this point. It is also attractive in as far as (1) it allows experiences to represent properties other than traditional sensory qualities, and (2) it allows for the identification of objects of experience and objects of perception in the case of experiences that constitute perception.
 According to the act/object analysis of experience, every experience with content involves an object of experience to which the subject is related by an act of awareness (the event of experiencing that object). This is meant to apply not only to perceptions, which have material objects (whatever is perceived), but also to experiences like hallucinations and dream experiences, which do not. Such experiences none the less appear to represent something, and their objects are supposed to be whatever it is that they represent. Act/object theorists may differ on the nature of objects of experience, which have been treated as properties. Meinongian objects (which may not exist or have any form of being), and, more commonly private mental entities with sensory qualities. (The term ‘sense-data’ is now usually applied to the latter, but has also been used as a general term for objects of sense experiences, as in the work of G. E. Moore) Act/object theorists may also differ on the relationship between objects of experience and objects of perception. In terms of perception (of which we are ‘indirectly aware’) are always distinct from objects of experience (of which we are ‘directly aware’). Meinongian, however, may treat objects of perception as existing objects of experience. But sense-datum theorists must either deny that there are such experiences or admit contradictory objects. Still, most philosophers will feel that the Meinongian’s acceptance of impossible objects is too high a price to pay for these benefits.
 A general problem for the act/object analysis is that the question of whether two subjects are experiencing one and the same thing (as opposed to having exactly similar experiences) appears to have an answer only on the assumption that the experiences concerned are perceptions with material objects. But in terms of the act/object analysis the question must have an answer even when this condition is not satisfied. (The answer is always negative on the sense-datum theory; it could be positive on other versions of the act/object analysis, depending on the facts of the case.)
 In view of the above problems, the case for the act/object analysis should be reassessed. The phenomenological argument is not, on reflection, convincing, for it is easy enough to grant that any experience appears to present ‘us’ with an object without accepting that it actually does. The semantic argument is more impressive, but is none the less answerable. The seemingly relational structure of attributions of experience is a challenge dealt with below in connection with the adverbial theory. Apparent reference to and quantification over objects of experience can be handled by analysing them as reference to experiences themselves and quantification over experiences tacitly typed according to content. Thus, ‘The after-image that John experienced was colourfully appealing’ becomes ‘John’s after-image experience was an experience of colour’, and ‘Macbeth saw something that his wife did not see’ becomes ‘Macbeth had a visual experience that his wife did not have’.
 Pure cognitivism attempts to avoid the problems facing the act/object analysis by reducing experiences to cognitive events or associated disposition, e.g., Susy’s experience of a rough surface beneath her hand might be identified with the event of her acquiring the belief that there is a rough surface beneath her hand, or, if she does not acquire this belief, with a disposition to acquire it that has somehow been blocked.
 This position has attractions. It does full justice to the cognitive contents of experience, and to the important role of experience as a source of belief acquisition. It would also help clear the way for a naturalistic theory of mind, since there seems to be some prospect of a physicalist/functionalist account of belief and other intentional states. But pure cognitivism is completely undermined by its failure to accommodate the fact that experiences have a felt character that cannot be reduced to their content, as aforementioned.
 The adverbial theory is an attempt to undermine the act/object analysis by suggesting a semantic account of attributions of experience that does not require objects of experience. Unfortunately, the oddities of explicit adverbializations of such statements have driven off potential supporters of the theory. Furthermore, the theory remains largely undeveloped, and attempted refutations have traded on this. It may, however, be founded on sound basis intuitions, and there is reason to believe that an effective development of the theory (which is merely hinting at) is possible.
 The relevant intuitions are (1) that when we say that someone is experiencing ‘an A’, or has an experience ‘of an A’, we are using this content-expression to specify the type of thing that the experience is especially apt to fit, (2) that doing this is a matter of saying something about the experience itself (and maybe about the normal causes of like experiences), and (3) that it is no-good of reasons to posit of its position to presuppose that of any involvements, is that its descriptions of an object in which the experience is. Thus the effective role of the content-expression in a statement of experience is to modify the verb it compliments, not to introduce a special type of object.
 Perhaps, the most important criticism of the adverbial theory is the ‘many property problem’, according to which the theory does not have the resources to distinguish between, e.g.,
 (1)   Frank has an experience of a brown triangle
and:
 (2)   Frank has an experience of brown and an experience of a triangle.
Which is entailed by (1) but does not entail it. The act/object analysis can easily accommodate the difference between (1) and (2) by claiming that the truth of (1) requires a single object of experience that is both brown and triangular, while that of the (2) allows for the possibility of two objects of experience, one brown and the other triangular, however, (1) is equivalent to:
 (1*)   Frank has an experience of something’s being both brown and triangular.
And (2) is equivalent to:
 (2*)   Frank has an experience of something’s being brown and an experience of something’s being triangular,
and the difference between these can be explained quite simply in terms of logical scope without invoking objects of experience. The Adverbialists may use this to answer the many-property problem by arguing that the phrase ‘a brown triangle’ in (1) does the same work as the clause ‘something’s being both brown and triangular’ in (1*). This is perfectly compatible with the view that it also has the ‘adverbial’ function of modifying the verb ‘has an experience of’, for it specifies the experience more narrowly just by giving a necessary condition for the satisfaction of the experience (the condition being that there are something both brown and triangular before Frank).
 A final position that should be mentioned is the state theory, according to which a sense experience of an ‘A’ is an occurrent, non-relational state of the kind that the subject would be in when perceiving an ‘A’. Suitably qualified, this claim is no doubt true, but its significance is subject to debate. Here it is enough to remark that the claim is compatible with both pure cognitivism and the adverbial theory, and that state theorists are probably best advised to adopt adverbials as a means of developing their intuitions.
 Yet, clarifying sense-data, if taken literally, is that which is given by the senses. But in response to the question of what exactly is so given, sense-data theories posit private showings in the consciousness of the subject. In the case of vision this would be a kind of inner picture show which itself only indirectly represents aspects of the external world that has in and of itself a worldly representation. The view has been widely rejected as implying that we really only see extremely thin coloured pictures interposed between our mind’s eye and reality. Modern approaches to perception tend to reject any conception of the eye as a camera or lense, simply responsible for producing private images, and stress the active life of the subject in and of the world, as the determinant of experience.
 Nevertheless, the argument from illusion is of itself the usually intended directive to establish that certain familiar facts about illusion disprove the theory of perception called naïevity or direct realism. There are, however, many different versions of the argument that must be distinguished carefully. Some of these distinctions centre on the content of the premises (the nature of the appeal to illusion); others centre on the interpretation of the conclusion (the kind of direct realism under attack). Let ‘us’ set about by distinguishing the importantly different versions of direct realism which one might take to be vulnerable to familiar facts about the possibility of perceptual illusion.
 A crude statement of direct realism might go as follows. In perception, we sometimes directly perceive physical objects and their properties, we do not always perceive physical objects by perceiving something ‘else’, e.g., a sense-datum. There are, however, difficulties with this formulation of the view, as for one thing a great many philosophers who are ‘not’ direct realists would admit that it is a mistake to describe people as actually ‘perceiving’ something other than a physical object. In particular, such philosophers might admit, we should never say that we perceive sense-data. To talk that way would be to suppose that we should model our understanding of our relationship to sense-data on our understanding of the ordinary use of perceptual verbs as they describe our relation to and of the physical world, and that is the last thing paradigm sense-datum theorists should want. At least, many of the philosophers who objected to direct realism would prefer to express in what they were of objecting too in terms of a technical (and philosophically controversial) concept such as ‘acquaintance’. Using such a notion, we could define direct realism this way: In ‘veridical’ experience we are directly acquainted with parts, e.g., surfaces, or constituents of physical objects. A less cautious verison of the view might drop the reference to veridical experience and claim simply that in all experience we are directly acquainted with parts or constituents of physical objects. The expressions ‘knowledge by acquaintance’ and ‘knowledge by description’, and the distinction they mark between knowing ‘things’ and knowing ‘about’ things, are generally associated with Bertrand Russell (1872-1970), that scientific philosophy required analysing many objects of belief as ‘logical constructions’ or ‘logical fictions’, and the programme of analysis that this inaugurated dominated the subsequent philosophy of logical atomism, and then of other philosophers, Russell’s ‘The Analysis of Mind,’ the mind itself is treated in a fashion reminiscent of Hume, as no more than the collection of neutral perceptions or sense-data that make up the flux of conscious experience, and that looked at another way that also was to make up the external world (neutral monism), but ‘An Inquiry into Meaning and Truth’ (1940) represents a more empirical approach to the problem. Yet, philosophers have perennially investigated this and related distinctions using varying terminology.
 Distinction in our ways of knowing things, highlighted by Russell and forming a central element in his philosophy after the discovery of the theory of ‘definite descriptions’. A thing is known by acquaintance when there is direct experience of it. It is known by description if it can only be described as a thing with such-and-such properties. In everyday parlance, I might know my spouse and children by acquaintance, but know someone as ‘the first person born at sea’ only by description. However, for a variety of reasons Russell shrinks the area of things that can be known by acquaintance until eventually only current experience, perhaps my own self, and certain universals or meanings qualify anything else is known only as the thing that has such-and-such qualities.
 Because one can interpret the relation of acquaintance or awareness as one that is not ‘epistemic’, i.e., not a kind of propositional knowledge, it is important to distinguish the above aforementioned views read as ontological theses from a view one might call ‘epistemological direct realism? In perception we are, on at least some occasions, non-inferentially justified in believing a proposition asserting the existence of a physical object. Since it is that these objects exist independently of any mind that might perceive them, and so it thereby rules out all forms of idealism and phenomenalism, which hold that there are no such independently existing objects. Its being to ‘direct’ realism rules out those views defended under the cubic of ‘critical naive realism’, or ‘representational realism’, in which there is some non-physical intermediary  -usually called a ‘sense-datum’ or a ‘sense impression’  -that must first be perceived or experienced in order to perceive the object that exists independently of this perception. Often the distinction between direct realism and other theories of perception is explained more fully in terms of what is ‘immediately’ perceived, than ‘mediately’ perceived. What relevance does illusion have for these two forms of direct realism?
 The fundamental premise of the arguments is from illusion seems to be the theses that things can appear to be other than they are. Thus, for example, straight sticks when immerged in water looks bent, a penny when viewed from certain perspective appears as an illusory spatial elliptic circularity, when something that is yellow when place under red fluorescent light looks red. In all of these cases, one version of the argument goes, it is implausible to maintain that what we are directly acquainted with is the real nature of the object in question. Indeed, it is hard to see how we can be said to be aware of the really physical object at all. In the above illusions the things we were aware of actually were bent, elliptical and red, respectively. But, by hypothesis, the really physical objects lacked these properties. Thus, we were not aware of the substantial reality of been real as a  physical objects or theory.
 So far, if the argument is relevant to any of the direct realisms distinguished above, it seems relevant only to the claim that in all sense experience we are directly acquainted with parts or constituents of physical objects. After all, even if in illusion we are not acquainted with physical objects, but their surfaces, or their constituents, why should we conclude anything about the hidden nature of our relations to the physical world in veridical experience?
 We are supposed to discover the answer to this question by noticing the similarities between illusory experience and veridical experience and by reflecting on what makes illusion possible at all. Illusion can occur because the nature of the illusory experience is determined, not just by the nature of the object perceived, but also by other conditions, both external and internal as becoming of an inner or as the outer experience. But all of our sensations are subject to these causal influences and it would be gratuitous and arbitrary to select from indefinitely of many and subtly different perceptual experiences some special ones those that get ‘us’ in touch with the ‘real’ nature of the physical world and its surrounding surfaces. Red fluorescent light affects the way thing’s look, but so does sunlight. Water reflects light, but so does air. We have no unmediated access to the external world.
 Still, why should we consider that we are aware of something other than a physical object in experience? Why should we not conclude that to be aware of a physical object is just to be appeared to by that object in a certain way? In its best-known form the adverbial theory of something proposes that the grammatical object of a statement attributing an experience to someone be analysed as an adverb. For example,
 (A) Rod is experiencing a coloured square.
Is rewritten as?
 Rod is experiencing, (coloured square)-ly
This is presented as an alternative to the act/object analysis, according to which the truth of a statement like (A) requires the existence of an object of experience corresponding to its grammatical object. A commitment to t he explicit adverbializations of statements of experience is not, however, essential to adverbialism. The core of the theory consists, rather, in the denial of objects of experience (as opposed ti objects of perception) coupled with the view that the role of the grammatical object in a statement of experience is to characterize more fully te sort of experience that is being attributed to the subject. The claim, then, is that the grammatical object is functioning as a modifier and, in particular, as a modifier of a verb. If it as a special kind of adverb at the semantic level.
 At this point, it might be profitable to move from considering the possibility of illusion to considering the possibility of hallucination. Instead of comparing paradigmatic veridical perception with illusion, let ‘us’ compare it with complete hallucination. For any experiences or sequence of experiences we take to be veridical, we can imagine qualitatively indistinguishable experiences occurring as part of a hallucination. For those who like their philosophical arguments spiced with a touch of science, we can imagine that our brains were surreptitiously removed in the night, and unbeknown to ‘us’ are being stimulated by a neurophysiologist so as to produce the very sensations that we would normally associate with a trip to the Grand Canyon. Currently permit ‘us’ into appealing of what we are aware of in this complete hallucination that is obvious that we are not awaken to the sparking awareness of physical objects, their surfaces, or their constituents. Nor can we even construe the experience as one of an object’s appearing to ‘us’ in a certain way. It is after all a complete hallucination and the objects we take to exist before ‘us’ are simply not there. But if we compare hallucinatory experience with the qualitatively indistinguishable veridical experiences, should we most conclude that it would be ‘special’ to suppose that in veridical experience we are aware of something radically different from what we are aware of in hallucinatory experience? Again, it might help to reflect on our belief that the immediate cause of hallucinatory experience and veridical experience might be the very same brain event, and it is surely implausible to suppose that the effects of this same cause are radically different  -acquaintance with physical objects in the case of veridical experience: Something else in the case of hallucinatory experience.
 This version of the argument from hallucination would seem to address straightforwardly the ontological versions of direct realism. The argument is supposed to convince ‘us’ that the ontological analysis of sensation in both veridical and hallucinatory experience should give ‘us’ the same results, but in the hallucinatory case there is no plausible physical object, constituent of a physical object, or surface of a physical object with which additional premiss we would also get an argument against epistemological direct realism. That premiss is that in a vivid hallucinatory experience we might have precisely the same justification for believing (falsely) what we do about the physical world as we do in the analogous, phenomenological indistinguishable, veridical experience. But our justification for believing that there is a table before ‘us’ in the course of a vivid hallucination of a table are surely not non-inferential in character. It certainly is not, if non-inferential justifications are supposedly a consist but yet an unproblematic access to the fact that makes true our belief  -by hypothesis the table does not exist. But if the justification that hallucinatory experiences give ‘us’ the same as the justification we get from the parallel veridical experience, then we should not describe a veridical experience as giving ‘us non-inferential justification for believing in the existence of physical objects. In both cases we should say that we believe what we do about the physical world on the basis of what we know directly about the character of our experience.
 In this brief space, I can only sketch some of the objections that might be raised against arguments from illusion and hallucination. That being said, let us begin with a criticism that accepts most of the presuppositions of the arguments. Even if the possibility of hallucination establishes that in some experience we are not acquainted with constituents of physical objects, it is not clear that it establishes that we are never acquainted with a constituent of physical objects. Suppose, for example, that we decide that in both veridical and hallucinatory experience we are acquainted with sense-data. At least some philosophers have tried to identify physical objects with ‘bundles’ of actual and possible sense-data.
 To establish inductively that sensations are signs of physical objects one would have to observe a correlation between the occurrence of certain sensations and the existence of certain physical objects. But to observe such a correlation in order to establish a connection, one would need independent access to physical objects and, by hypothesis, this one cannot have. If one further adopts the verificationist’s stance that the ability to comprehend is parasitic on the ability to confirm, one can easily be driven to Hume’s conclusion:
 Let us chance our imagination to the heavens, or to the utmost limits of the universe, we never really advance a step beyond ourselves, nor can conceivable any kind of existence, but those perceptions, which have appear̀d in that narrow compass. This is the universe of the imagination, nor have we have any idea but what is there  Reduced. (Hume, 1739-40, pp. 67-8).
If one reaches such a conclusion but wants to maintain the intelligibility and verifiability of the assertion about the physical world, one can go either the idealistic or the phenomenalistic route.
 However, hallucinatory experiences on this view is non-veridical precisely because the sense-data one is acquainted with in hallucination do not bear the appropriate relations to other actual and possible sense-data. But if such a view were plausible one could agree that one is acquainted with the same kind of a thing in veridical and non-veridical experience but insists that there is still a sense in which in veridical experience one is acquainted with constituents of a physical object?
 A different sort of objection to the argument from illusion or hallucination concerns its use in drawing conclusions we have not stressed in the above discourses. I, have in mentioning this objection, may to underscore an important feature of the argument. At least some philosophers (Hume, for example) have stressed the rejection of direct realism on the road to an argument for general scepticism with respect to the physical world. Once one abandons epistemological; direct realisms, one has an uphill battle indicating how one can legitimately make the inferences from sensation to physical objects. But philosophers who appeal to the existence of illusion and hallucination to develop an argument for scepticism can be accused of having an epistemically self-defeating argument. One could justifiably infer sceptical conclusions from the existence of illusion and hallucination only if one justifiably believed that such experiences exist, but if one is justified in believing that illusion exists, one must be justified in believing at least, some facts about the physical world (for example, that straight sticks look bent in water). The key point to stress in relying to such arguments is, that strictly speaking, the philosophers in question need only appeal to the ‘possibility’ of a vivid illusion and hallucination. Although it would have been psychologically more difficult to come up with arguments from illusion and hallucination if we did not believe that we actually had such experiences, I take it that most philosophers would argue that the possibility of such experiences is enough to establish difficulties with direct realism. Indeed, if one looks carefully at the argument from hallucination discussed earlier, one sees that it nowhere makes any claims about actual cases of hallucinatory experience.
 Another reply to the attack on epistemological direct realism focuses on the implausibility of claiming that there is any process of ‘inference’ wrapped up in our beliefs about the world and its surrounding surfaces. Even if it is possible to give a phenomenological description of the subjective character of sensation, it requires a special sort of skill that most people lack. Our perceptual beliefs about the physical world are surely direct, at least in the sense that they are unmediated by any sort of conscious inference from premisses describing something other than a physical object. The appropriate reply to this objection, however, is simply to acknowledge the relevant phenomenological fact and point out that from the perceptive of epistemologically direct realism, the philosopher is attacking a claim about the nature of our justification for believing propositions about the physical world. Such philosophers need carry out of any comment at all about the causal genesis of such beliefs.
 As mentioned that proponents of the argument from illusion and hallucination have often intended it to establish the existence of sense-data, and many philosophers have attacked the so-called sense-datum inference presupposed in some statements of the argument. When the stick looked bent, the penny looked elliptical and the yellow object looked red, the sense-datum theorist wanted to infer that there was something bent, elliptical and red, respectively. But such an inference is surely suspect. Usually, we do not infer that because something appears to have a certain property, that affairs that affecting something that has that property. When in saying that Jones looks like a doctor, I surely would not want anyone to infer that there must actually be someone there who is a doctor. In assessing this objection, it will be important to distinguish different uses words like ‘appears’ and ‘looks’. At least, sometimes to say that something looks ‘F’ way and the sense-datum inference from an F ‘appearance’ in this sense to an actual ‘F’ would be hopeless. However, it also seems that we use the ‘appears’/’looks’ terminology to describe the phenomenological character of our experience and the inference might be more plausible when the terms are used this way. Still, it does seem that the arguments from illusion and hallucination will not by themselves constitute strong evidence for sense-datum theory. Even if one concludes that there is something common to both the hallucination of a red thing and a veridical visual experience of a red thing, one need not describe a common constituent as awarenesses of something red. The adverbial theorist would prefer to construe the common experiential state as ‘being appeared too redly’, a technical description intended only to convey the idea that the state in question need not be analysed as relational in character. Those who opt for an adverbial theory of sensation need to make good the claim that their artificial adverbs can be given a sense that is not parasitic upon an understanding of the adjectives transformed into verbs. Still, other philosophers might try to reduce the common element in veridical and non-veridical experience to some kind of intentional state.  More like belief or judgement. The idea here is that the only thing common to the two experiences is the fact that in both I spontaneously takes there to be present an object of a certain kind.
 The selfsame objections can be started within the general framework presupposed by proponents of the arguments from illusion and hallucination. A great many contemporary philosophers, however, uncomfortable with the intelligibility of the concepts needed to make sense of the theories attacked even. Thus, at least, some who object to the argument from illusion do so not because they defend direct realism. Rather they think there is something confused about all this talk of direct awareness or acquaintance. Contemporary Externalists, for example, usually insist that we understand epistemic concepts by appeal: To nomologically connections. On such a view the closest thing to direct knowledge would probably be something by other beliefs. If we understand direct knowledge this way, it is not clar how the phenomena of illusion and hallucination would be relevant to claim that on, at least some occasions our judgements about the physical world are reliably produced by processes that do not take as their input beliefs about something else.