Philosophical skepticism is a philosophical school of thought that questions the possibility of certainty in knowledge. Skeptic philosophers from different historical periods adopted different principles and arguments, but their ideology can be generalized as either the denial of possibility of all knowledge or the suspension of judgement due to the inadequacy of evidence. Skepticism covers a range of different positions. In the ancient world there were two main skeptical traditions. Academic skepticism took the dogmatic position. Radical skepticism ends in the paradoxical claim that one cannot know anything—including that one cannot know about knowing anything. Skepticism can be classified according to its scope. Local skepticism involves being skeptical about particular areas of knowledge, e.g. moral skepticism, skepticism about the external world, or skepticism about other minds, whereas global skepticism is skeptical about the possibility of any knowledge at all. Skepticism can be classified according to its method.
In the Western tradition there are two basic approaches to skepticism. Cartesian skepticism —named somewhat misleadingly after René Descartes, not a skeptic but used some traditional skeptical arguments in his Meditations to help establish his rationalist approach to knowledge— attempts to show that any proposed knowledge claim can be doubted. Agrippan skepticism focuses on the process of justification rather than the possibility of doubt. According to this view there are three ways in which one might attempt to justify a claim but none of them are adequate: one can keep on providing further justification but this leads to an infinite regress. Philosophical skepticism is distinguished from methodological skepticism in that philosophical skepticism is an approach that questions the possibility of certainty in knowledge, whereas methodological skepticism is an approach that subjects all knowledge claims to scrutiny with the goal of sorting out true from false claims. Philosophical skepticism begins with the claim that the skeptic does not have knowledge.
Some adherents maintain. It could be argued, he appears to have thought that if people continue to ask questions they might come to have knowledge. Some skeptics have gone further and claimed that true knowledge is impossible, for example the Academic school in Ancient Greece well after the time of Carneades. A third skeptical approach would be neither to reject the possibility of knowledge. Skepticism can be either about particular areas. A'global' skeptic argues that he does not know anything to be either true or false. Academic global skepticism has great difficulty in supporting this claim while maintaining philosophical rigor, since it seems to require that nothing can be known—except for the knowledge that nothing can be known, though in its probabilistic form it can use and support the notion of weight of evidence. Thus, some probabilists avoid extreme skepticism by maintaining that they are'reasonably certain' some things are real or true; as for using probabilistic arguments to defend skepticism, in a sense this enlarges or increases scepticism, while the defence of empiricism by Empiricus weakens skepticism and strengthens dogmatism by alleging that sensory appearances are beyond doubt.
Much Kant would re-define "dogmatism" to make indirect realism about the external world seem objectionable. While many Hellenists, outside of Empiricus, would maintain that everyone, not sceptical about everything is a dogmatist, this position would seem too extreme for most philosophers. A Pyrrhonian global skeptic labors under no such modern constraint, since Pyrrho only alleged that he did not know anything, he made no statement about the possibility of knowledge. Nor did Arcesilaus feel bound, since he corrected Socrates's "I only know that I know nothing" by adding "I don't know that", thus more rejecting dogmatism. Local skeptics deny that people can have knowledge of a particular area, they may be skeptical about the possibility of one form of knowledge without doubting other forms. Different kinds of local skepticism may emerge, depending on the area. A person may doubt the truth value of different types of journalism, for example, depending on the types of media they trust. In Islamic philosophy, skepticism was established by Al-Ghazali, known in the West as "Algazel", as part of the Ash'ari school of Islamic theology.
Francisco Sanches's That Nothing is Known is one of the crucial texts of Renaissance skepticism. Skepticism, as an epistemological argument, poses the question of whether knowledge, in the first place, is possible. Skeptics argue that the belief in something does not justify an assertion of knowledge of it. In this, skeptics oppose dogmatic foundationalism, which states that there have to be some basic positions that are self-justified or beyond justification, without reference to others; the skeptical response to this can take several approaches. First, claiming that "basic positions" must exist amounts to the logical fallacy of argument from ignorance combined with the slippery slope. Among other arguments, skeptics used Agrippa's trilemma, named after Agrippa the
George Berkeley – known as Bishop Berkeley – was an Irish philosopher whose primary achievement was the advancement of a theory he called "immaterialism". This theory denies the existence of material substance and instead contends that familiar objects like tables and chairs are only ideas in the minds of perceivers and, as a result, cannot exist without being perceived. Berkeley is known for his critique of abstraction, an important premise in his argument for immaterialism. Berkeley was the namesake of the city of Berkeley, most famous as the home of the University of California, Berkeley. In 1709, Berkeley published his first major work, An Essay towards a New Theory of Vision, in which he discussed the limitations of human vision and advanced the theory that the proper objects of sight are not material objects, but light and colour; this foreshadowed his chief philosophical work, A Treatise Concerning the Principles of Human Knowledge, in 1710, after its poor reception, he rewrote in dialogue form and published under the title Three Dialogues between Hylas and Philonous in 1713.
In this book, Berkeley's views were represented by Philonous, while Hylas embodies the Irish thinker's opponents, in particular John Locke. Berkeley argued against Isaac Newton's doctrine of absolute space and motion in De Motu, published 1721, his arguments were a precursor to the views of Einstein. In 1732, he published Alciphron, a Christian apologetic against the free-thinkers, in 1734, he published The Analyst, a critique of the foundations of calculus, influential in the development of mathematics, his last major philosophical work, begins by advocating the medicinal use of tar water and continues to discuss a wide range of topics, including science and theology. Interest in Berkeley's work increased after World War II because he tackled many of the issues of paramount interest to philosophy in the 20th century, such as the problems of perception, the difference between primary and secondary qualities, the importance of language. Berkeley was born at his family home, Dysart Castle, near Thomastown, County Kilkenny, the eldest son of William Berkeley, a cadet of the noble family of Berkeley.
Little is known of his mother. He was educated at Kilkenny College and attended Trinity College, where he was elected a Scholar in 1702, earning a bachelor's degree in 1704 and completing a master's degree in 1707, he remained at Trinity College after completion of his degree as Greek lecturer. His earliest publication was on mathematics, but the first that brought him notice was his An Essay towards a New Theory of Vision, first published in 1709. In the essay, Berkeley examines visual distance, magnitude and problems of sight and touch. While this work raised much controversy at the time, its conclusions are now accepted as an established part of the theory of optics; the next publication to appear was the Treatise Concerning the Principles of Human Knowledge in 1710, which had great success and gave him a lasting reputation, though few accepted his theory that nothing exists outside the mind. This was followed in 1713 by Three Dialogues between Hylas and Philonous, in which he propounded his system of philosophy, the leading principle of, that the world, as represented by our senses, depends for its existence on being perceived.
For this theory, the Principles gives the Dialogues the defence. One of his main objectives was to combat the prevailing materialism of his time; the theory was received with ridicule, while those such as Samuel Clarke and William Whiston, who did acknowledge his "extraordinary genius," were convinced that his first principles were false. Shortly afterwards, Berkeley visited England and was received into the circle of Addison and Steele. In the period between 1714 and 1720, he interspersed his academic endeavours with periods of extensive travel in Europe, including one of the most extensive Grand Tours of the length and breadth of Italy undertaken. In 1721, he took Holy Orders in the Church of Ireland, earning his doctorate in divinity, once again chose to remain at Trinity College Dublin, lecturing this time in Divinity and in Hebrew. In 1721/2 he was made Dean of Dromore and, in 1724, Dean of Derry. In 1723, following her violent quarrel with Jonathan Swift, her intimate friend for many years, Esther Vanhomrigh named Berkeley her co-heir along with the barrister Robert Marshall.
Swift said generously that he did not grudge Berkeley his inheritance, much of which vanished in a lawsuit in any event. A story that Berkeley and Marshall disregarded a condition of the inheritance that they must publish the correspondence between Swift and Vanessa is untrue. In 1725, he began the project of founding a college in Bermuda for training ministers and missionaries in the colony, in pursuit of which he gave up his deanery with its income of £1100. In 1728, he married Anne Forster, daughter of John Forster, Chief Justice of the Irish Common Pleas, his first wife Rebecca Monck, he went to America on a salary of £100 per annum. He landed near Newport, Rhode Island, where he bought a plantation at Middletown – the famous "Whitehall", it has been claimed that "he introduced Palladianism into America by borrowing a design from Kent's Designs of Inigo Jones for the door-case of his hous
Ludwig Josef Johann Wittgenstein was an Austrian philosopher who worked in logic, the philosophy of mathematics, the philosophy of mind, the philosophy of language. From 1929 to 1947, Wittgenstein taught at the University of Cambridge. During his lifetime he published just one slim book, the 75-page Tractatus Logico-Philosophicus, one article, one book review and a children's dictionary, his voluminous manuscripts were published posthumously. Philosophical Investigations appeared as a book in 1953, has since come to be recognised as one of the most important works of philosophy in the 20th century, his teacher, Bertrand Russell, described Wittgenstein as "the most perfect example I have known of genius as traditionally conceived. Born in Vienna into one of Europe's richest families, he inherited a fortune from his father in 1913, he made some donations to artists and writers, in a period of severe personal depression after the First World War, he gave away his entire fortune to his brothers and sisters.
Three of his brothers committed suicide, which Wittgenstein had contemplated. He left academia several times—serving as an officer on the front line during World War I, where he was decorated a number of times for his courage, he described philosophy as "the only work that gives me real satisfaction". His philosophy is divided into an early period, exemplified by the Tractatus, a period, articulated in the Philosophical Investigations; the early Wittgenstein was concerned with the logical relationship between propositions and the world and believed that by providing an account of the logic underlying this relationship, he had solved all philosophical problems. The Wittgenstein rejected many of the assumptions of the Tractatus, arguing that the meaning of words is best understood as their use within a given language-game. A survey among American university and college teachers ranked the Investigations as the most important book of 20th-century philosophy, standing out as "the one crossover masterpiece in twentieth-century philosophy, appealing across diverse specializations and philosophical orientations."
The Investigations ranked 54th on a list of most influential twentieth-century works in cognitive science prepared by the University of Minnesota's Center for Cognitive Sciences. However, in the words of his friend Georg Henrik von Wright, he believed "his ideas were misunderstood and distorted by those who professed to be his disciples, he doubted. He once said he felt as though he was writing for people who would think in a different way, breathe a different air of life, from that of present-day men." According to a family tree prepared in Jerusalem after World War II, Wittgenstein's paternal great-great-grandfather was Moses Meier, a Jewish land agent who lived with his wife, Brendel Simon, in Bad Laasphe in the Principality of Wittgenstein, Westphalia. In July 1808, Napoleon issued a decree that everyone, including Jews, must adopt an inheritable family surname, so Meier's son Moses, took the name of his employers, the Sayn-Wittgensteins, became Moses Meier Wittgenstein, his son, Hermann Christian Wittgenstein—who took the middle name "Christian" to distance himself from his Jewish background—married Fanny Figdor Jewish, who converted to Protestantism just before they married, the couple founded a successful business trading in wool in Leipzig.
Ludwig's grandmother Fanny was a first cousin of the famous violinist Joseph Joachim. They had 11 children—among them Wittgenstein's father. Karl Otto Clemens Wittgenstein became an industrial tycoon, by the late 1880s was one of the richest men in Europe, with an effective monopoly on Austria's steel cartel. Thanks to Karl, the Wittgensteins became the second wealthiest family in the Austro-Hungarian Empire, only behind the Rothschilds. Karl Wittgenstein was viewed as the Austrian equivalent of Andrew Carnegie, with whom he was friends, was one of the wealthiest men in the world by the 1890s; as a result of his decision in 1898 to invest in the Netherlands and in Switzerland as well as overseas in the US, the family was to an extent shielded from the hyperinflation that hit Austria in 1922. However, their wealth diminished due to post-1918 hyperinflation and subsequently during the Great Depression, although as late as 1938 they owned 13 mansions in Vienna alone. Wittgenstein's mother was Leopoldine Maria Josefa Kalmus, known among friends as Poldi.
Her father was a Bohemian Jew and her mother was Austrian-Slovene Catholic—she was Wittgenstein's only non-Jewish grandparent. She was an aunt of the Nobel Prize laureate Friedrich Hayek on her maternal side. Wittgenstein was born at 8:30 pm on 26 April 1889 in the so-called "Wittgenstein Palace" at Alleegasse 16, now the Argentinierstrasse, near the Karlskirche. Karl and Poldi had nine children in all—four girls: Hermine, Helene, a fourth daughter Dora who died as a baby; the children were baptized as Catholics, received formal Catholic instruction, were raised in an exceptionally intense environmen
Reductionism is any of several related philosophical ideas regarding the associations between phenomena which can be described in terms of other simpler or more fundamental phenomena. The Oxford Companion to Philosophy suggests that reductionism is "one of the most used and abused terms in the philosophical lexicon" and suggests a three part division: Ontological reductionism: a belief that the whole of reality consists of a minimal number of parts. Methodological reductionism: the scientific attempt to provide explanation in terms of smaller entities. Theory reductionism: the suggestion that a newer theory does not replace or absorb an older one, but reduces it to more basic terms. Theory reduction itself is divisible into three parts: translation and explanation. Reductionism can be applied to any phenomenon, including objects, explanations and meanings. For the sciences, application of methodological reductionism attempts explanation of entire systems in terms of their individual, constituent parts and their interactions.
For example, the temperature of a gas is reduced to nothing beyond the average kinetic energy of its molecules in motion. Thomas Nagel speaks of'psychophysical reductionism', as do others and'physico-chemical reductionism', again as do others. In a simplified and sometimes contested form, such reductionism is said to imply that a system is nothing but the sum of its parts. However, a more nuanced opinion is that a system is composed of its parts, but the system will have features that none of the parts have. "The point of mechanistic explanations is showing how the higher level features arise from the parts."Other definitions are used by other authors. For example, what John Polkinghorne terms'conceptual' or'epistemological' reductionism is the definition provided by Simon Blackburn and by Jaegwon Kim: that form of reductionism concerning a program of replacing the facts or entities entering statements claimed to be true in one type of discourse with other facts or entities from another type, thereby providing a relationship between them.
Such an association is provided where the same idea can be expressed by "levels" of explanation, with higher levels reducible if need be to lower levels. This use of levels of understanding in part expresses our human limitations in remembering detail. However, "most philosophers would insist that our role in conceptualizing reality does not change the fact that different levels of organization in reality do have different'properties'."Reductionism represents a certain perspective of causality. In a reductionist framework, the phenomena that can be explained in terms of relations between other more fundamental phenomena, are termed epiphenomena. There is an implication that the epiphenomenon exerts no causal agency on the fundamental phenomena that explain it; the epiphenomena are sometimes said to be "nothing but" the outcome of the workings of the fundamental phenomena, although the epiphenomena might be more and efficiently described in different terms. There is a tendency to avoid considering an epiphenomenon as being important in its own right.
This attitude may extend to cases where the fundamentals are not able to explain the epiphenomena, but are expected to by the speaker. In this way, for example, morality can be deemed to be "nothing but" evolutionary adaptation, consciousness can be considered "nothing but" the outcome of neurobiological processes. Reductionism should be distinguished from eliminationism: reductionists do not deny the existence of phenomena, but explain them in terms of another reality. For example, eliminationists deny the existence of life by their explanation in terms of physical and chemical processes. Reductionism does not preclude the existence of what might be termed emergent phenomena, but it does imply the ability to understand those phenomena in terms of the processes from which they are composed; this reductionist understanding is different from emergentism, which intends that what emerges in "emergence" is more than the sum of the processes from which it emerges. Most philosophers delineate three types of anti-reductionism.
Ontological reductionism is the belief that reality is composed of a minimum number of kinds of entities or substances. This claim is metaphysical, is most a form of monism, in effect claiming that all objects and events are reducible to a single substance. Richard Jones divides ontological reductionism into two: the reductionism of substances and the reduction of the number of structures operating in nature; this permits scientists and philosophers to affirm the former while being anti-reductionists regarding the latter. Nancey Murphy has claimed that there are two species of ontological reductionism: one that denies that wholes are anything more than their parts, she admits that the phrase "really real" is senseless but nonetheless has tried to explicate the supposed difference between the two. Ontological reductionism denies the idea of ontological emergence, claims that emergence is an epistemological phenomenon that only exists through analysis or de
Philosophical Investigations is a work by the philosopher Ludwig Wittgenstein. It was first published posthumously in 1953. Wittgenstein discusses numerous problems and puzzles in the fields of semantics, philosophy of mathematics, philosophy of psychology, philosophy of action, philosophy of mind, putting forth the view that conceptual confusions surrounding language use are at the root of most philosophical problems. Wittgenstein alleges that the problems are traceable to a set of related assumptions about the nature of language, which themselves presuppose a particular conception of the essence of language; this conception is considered and rejected for being too general. This view can be seen to contradict or discard much of what he argued in his earlier work Tractatus Logico-Philosophicus. Philosophical Investigations is influential. Within the analytic tradition, the book is considered by many as being one of the most important philosophical works of the 20th century, it continues to influence contemporary philosophers those studying mind and language.
Wittgenstein begins the book with a quotation from Augustine of Hippo, whom he cites as a proponent of the generalized and limited conception that he summarizes: The individual words in language name objects—sentences are combinations of such names. In this picture of language we find the roots of the following idea: Every word has a meaning; this meaning is correlated with the word. It is the object, he sets out throughout the rest of the book to demonstrate the limitations of this conception, including, he argues, with many traditional philosophical puzzles and confusions that arise as a result of this limited picture. Philosophical Investigations was not ready for publication when Wittgenstein died in 1951. G. E. M. Anscombe translated Wittgenstein's manuscript into English, it was first published in 1953. There are multiple editions of Philosophical Investigations with the popular third edition and 50th anniversary edition having been edited by Anscombe: First Edition: Macmillan Publishing Company, 1953.
Second Edition: Blackwell Publishers, 1958. Third Edition: Prentice Hall, 1973. 50th Anniversary Edition: Blackwell Publishers, 2001. This edition includes the original German text in addition to the English translation. Fourth Edition: Wiley-Blackwell, 2009; the text is divided into two parts, consisting of what Wittgenstein calls, in the preface, translated by Anscombe as "remarks". In the first part, these remarks are more than a paragraph long and are numbered sequentially. In the second part, the remarks numbered using Roman numerals. In the index, remarks from the first part are referenced by their number rather than page; the comparatively unusual nature of the second part is due to the fact that it comprises notes that Wittgenstein may have intended to re-incorporate into the first part. Subsequent to his death it was published as a "Part II" in the first and third editions. However, in light of continuing uncertainty about Wittgenstein's intentions regarding this material, the fourth edition re-titles "Part I" as "Philosophical Investigations" proper, "Part II" as "Philosophy of Psychology – A Fragment."
In standard references, a small letter following a page, section, or proposition number indicates a paragraph. Philosophical Investigations is unique in its approach to philosophy. A typical philosophical text presents a philosophical problem and critiques various alternative approaches to solving it, presents its approach, argues in favour of that approach. In contrast, Wittgenstein's book treats philosophy as an activity, rather along the lines of Socrates's famous method of maieutics. Rather than presenting a philosophical problem and its solution, Wittgenstein engages in a dialogue, where he provides a language-game, that describes how one might be inclined to think about it, shows why that inclination suffers from conceptual confusion; the following is an excerpt from the first entry in the book that exemplifies this method:...think of the following use of language: I send someone shopping. I give him a slip marked'five red apples', he takes the slip to the shopkeeper, who opens the drawer marked'apples' he looks up the word'red' in a table and finds a colour sample opposite it.
Well, I assume. Explanations come to an end somewhere.—But what is the meaning of the word'five'? No such thing was in question here; this example is typical of the book's style. We can see each of the steps in Wittgenstein's method: The reader is presented with a use of language: someone is sent shopping with an order on a slip. Wittgenstein supplies the response of one or more imagined interlocutors, he may put these statements in quotes to distinguish them from his own: "But how does he know where and how he is to look up the word'red' and what he is to do with the
Chrysippus of Soli was a Greek Stoic philosopher. He was a native of Soli, but moved to Athens as a young man, where he became a pupil of Cleanthes in the Stoic school; when Cleanthes died, around 230 BC, Chrysippus became the third head of the school. A prolific writer, Chrysippus expanded the fundamental doctrines of Zeno of Citium, the founder of the school, which earned him the title of Second Founder of Stoicism. Chrysippus excelled in logic, the theory of knowledge and physics, he created an original system of propositional logic in order to better understand the workings of the universe and role of humanity within it. He adhered to a deterministic view of fate, but sought a role for personal freedom in thought and action. Ethics, he thought, depended on understanding the nature of the universe, he taught a therapy of extirpating the unruly passions which depress and crush the soul, he initiated the success of Stoicism as one of the most influential philosophical movements for centuries in the Greek and Roman world.
Of his written works, none have survived except as fragments quoted in the works of authors. Segments of some of his works were discovered among the Herculaneum papyri. Chrysippus, the son of Apollonius of Tarsus, was born at Cilicia, he was slight in stature, is reputed to have trained as a long-distance runner. While still young, he lost his substantial inherited property when it was confiscated to the king's treasury. Chrysippus moved to Athens, where he became the disciple of Cleanthes, the head of the Stoic school, he is believed to have attended the courses of Arcesilaus and his successor Lacydes, in the Platonic Academy. Chrysippus threw himself eagerly into the study of the Stoic system, his reputation for learning among his contemporaries was considerable. He was noted for intellectual audacity and self-confidence and his reliance on his own ability was shown, among other things, in the request he is supposed to have made to Cleanthes: "Give me the principles, I will find the proofs myself."
He succeeded Cleanthes as head of the Stoic school when Cleanthes died, in around 230 BC. Chrysippus was a prolific writer, he is said to have gone without writing 500 lines a day and he composed more than 705 works. His desire to be comprehensive meant that he would take both sides of an argument and his opponents accused him of filling his books with the quotations of others, he was considered diffuse and obscure in his utterances and careless in his style, but his abilities were regarded, he came to be seen as a preeminent authority for the school. He died during the 143rd Olympiad at the age of 73. Diogenes Laërtius gives two different accounts of his death. In the first account, Chrysippus was seized with dizziness having drunk undiluted wine at a feast, died soon after. In the second account, he was watching a donkey eat some figs and cried out: "Now give the donkey a drink of pure wine to wash down the figs", whereupon he died in a fit of laughter, his nephew Aristocreon erected a statue in his honour in the Kerameikos.
Chrysippus was succeeded as head of the Stoic school by his pupil Zeno of Tarsus. Of his written works, none survived except as fragments quoted in the works of authors like Cicero, Galen and others. Segments from Logical Questions and On Providence were discovered among the Herculaneum papyri. A third work by Chrysippus may be among them. Chrysippus had a long and successful career of resisting the attacks of the Academy and hoped not to defend Stoicism against the assaults of the past, but against all possible attack in the future, he took the doctrines of Zeno and Cleanthes and crystallized them into what became the definitive system of Stoicism. He elaborated the physical doctrines of the Stoics and their theory of knowledge and he created much of their formal logic. In short, Chrysippus made the Stoic system, it was said that "without Chrysippus, there would have been no Stoa". Chrysippus created a system of propositional logic. Aristotle's term logic had been concerned with the interrelations of terms such as "Socrates" or "man".
Stoic logic, on the other hand, was concerned with the interrelations of propositions such as "it is day". Though the earlier Megarian dialecticians – Diodorus Cronus and Philo – had worked in this field and the pupils of Aristotle – Theophrastus and Eudemus – had investigated hypothetical syllogisms, it was Chrysippus who developed these principles into a coherent system of propositional logic. Chrysippus defined a proposition as "that, capable of being denied or affirmed as it is in itself" and gave examples of propositions such as "it is day" and "Dion is walking." He distinguished between simple and non-simple propositions, which in modern terminology are known as atomic and molecular propositions. A simple proposition is an elementary statement such as "it is day." Simple propositions are linked together to form non-simple propositions by the use of logical connectives. Chrysippus enumerated five kinds of molecular propositions according to the connective used: Thus several types of molecular propositions, familiar to modern logic, were listed by Chrysippus, including the conjunction, the disjunction, the conditional, Chrysippus studied their criteria of truth closely.
The first logicians to debate conditional statements were his pupil Philo. Writing five-hundred years Sextus Empiricus refers to a debate between Diodorus and Philo. Philo regarded all conditi
Ancient Greek philosophy
Ancient Greek philosophy arose in the 6th century BC and continued throughout the Hellenistic period and the period in which Ancient Greece was part of the Roman Empire. Philosophy was used to make sense out of the world in a non-religious way, it dealt with a wide variety of subjects, including astronomy, political philosophy, metaphysics, logic, biology and aesthetics. Greek philosophy has influenced much of Western culture since its inception. Alfred North Whitehead once noted: "The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato". Clear, unbroken lines of influence lead from ancient Greek and Hellenistic philosophers to Early Islamic philosophy, the European Renaissance and the Age of Enlightenment; some claim that Greek philosophy was in turn influenced by the older wisdom literature and mythological cosmogonies of the ancient Near East, though this is debated. Martin Litchfield West gives qualified assent to this view by stating that "contact with oriental cosmology and theology helped to liberate the early Greek philosophers' imagination.
But they taught themselves to reason. Philosophy as we understand it is a Greek creation". Subsequent philosophic tradition was so influenced by Socrates as presented by Plato that it is conventional to refer to philosophy developed prior to Socrates as pre-Socratic philosophy; the periods following this, up to and after the wars of Alexander the Great, are those of "classical Greek" and "Hellenistic" philosophy. The convention of terming those philosophers who were active prior to Socrates the pre-Socratics gained currency with the 1903 publication of Hermann Diels' Fragmente der Vorsokratiker, although the term did not originate with him; the term is considered useful because what came to be known as the "Athenian school" signaled a profound shift in the subject matter and methods of philosophy. The pre-Socratics were concerned with cosmology and mathematics, they were distinguished from "non-philosophers" insofar as they rejected mythological explanations in favor of reasoned discourse. Thales of Miletus, regarded by Aristotle as the first philosopher, held that all things arise from a single material substance, water.
It is not because he gave a cosmogony that John Burnet calls him the "first man of science," but because he gave a naturalistic explanation of the cosmos and supported it with reasons. According to tradition, Thales was able to predict an eclipse and taught the Egyptians how to measure the height of the pyramids. Thales inspired the Milesian school of philosophy and was followed by Anaximander, who argued that the substratum or arche could not be water or any of the classical elements but was instead something "unlimited" or "indefinite", he began from the observation that the world seems to consist of opposites, yet a thing can become its opposite. Therefore, they cannot be opposites but rather must both be manifestations of some underlying unity, neither; this underlying unity could not be any of the classical elements, since they were one extreme or another. For example, water is wet, the opposite of dry, the opposite of wet; this initial state is ageless and imperishable, everything returns to it according to necessity Anaximenes in turn held that the arche was air, although John Burnet argues that by this he meant that it was a transparent mist, the aether.
Despite their varied answers, the Milesian school was searching for a natural substance that would remain unchanged despite appearing in different forms, thus represents one of the first scientific attempts to answer the question that would lead to the development of modern atomic theory. Xenophanes was born in Ionia, where the Milesian school was at its most powerful, may have picked up some of the Milesians' cosmological theories as a result. What is known is that he argued that each of the phenomena had a natural rather than divine explanation in a manner reminiscent of Anaximander's theories and that there was only one god, the world as a whole, that he ridiculed the anthropomorphism of the Greek religion by claiming that cattle would claim that the gods looked like cattle, horses like horses, lions like lions, just as the Ethiopians claimed that the gods were snubnosed and black and the Thracians claimed they were pale and red-haired. Burnet says that Xenophanes was not, however, a scientific man, with many of his "naturalistic" explanations having no further support than that they render the Homeric gods superfluous or foolish.
He has been claimed as an influence on Eleatic philosophy, although, disputed, a precursor to Epicurus, a representative of a total break between science and religion. Pythagoras lived at the same time that Xenophanes did and, in contrast to the latter, the school that he founded sought to reconcile religious belief and reason. Little is known about his life with any reliability, no writings of his survive, so it is possible that he was a mystic whose successors introduced rationalism into Pythagoreanism, that he was a rationalist whose successors are responsible for the mysticism in Pythagoreanism, or that he was the author of the doctrine. Pythagoras is said to have been a disciple of Anaximander and to have imbib