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Greek philosophy

Classical (or "early") Greek philosophy focused on the role of reason and inquiry. In many ways it paved the way both to modern science and to modern philosophy. Clear unbroken lines of influence lead from early Greek philosophers, through early Muslim philosophy to the Renaissance, the Enlightenment, and the secular sciences of the modern day.

Table of contents
1 Pre-Socratic Philosophers
2 Socrates
3 Plato
4 Aristotle
5 Later Classical philosophers
6 The Neo-Platonists
7 Schools of thought in the Hellenistic period

Pre-Socratic Philosophers

The history of philosophy in the west begins with the Greeks, and particularly with a group of philosophers commonly called the pre-Socratics. This is not to deny the occurrence of other pre-philosophical rumblings in Egyptian, Semitic and Babylonian cultures. Certainly great thinkers and writers existed in each of these cultures, and we have evidence that some of the earliest Greek philosophers may have had contact with at least some of the products of Egyptian and Babylonian thought. However, the early Greek thinkers add at least one element which differentiates their thought from all those who came before them. For the first time in history, we discover in their writings something more than dogmatic assertions about the ordering of the world -- we find reasoned arguments for various beliefs about the world.

As it turns out, nearly all of the various cosmologies proposed by the early Greek philosophers are profoundly and demonstrably false, but this does not diminish their importance. For even if later philosophers summarily rejected the answers they provided, they could not escape their questions:

And the method the Greek philosophers followed in forming and transmitting their answers became just as important as the questions they asked. The pre-Socratic philosophers rejected traditional mythological explanations for the phenomena they saw around them in favor of more rational explanations. In other words they depended on reason and observation to illuminate the true nature of the would around them, and they used rational argument to advance their views to others. And though philosophers have argued at length about the relative weights that reason and observation should have, for two and a half millennia they have basically united in the use of the very method first used by the pre-Socratics.

Difficulties often arise in pinning down the ideas of the Pre-Socratic philosophers, and in determining the actual line of argument they used in supporting their particular views. This problem arises not from some defect in the men themselves or in their ideas, but simply from their separation from us in history. While most of these men produced significant texts, we have no complete versions of any of those texts. We have only quotations by later philosophers and historians, along with the occasional textual fragment.




Heraclitus of Ephesus

Xenophanes, Parmenides, and the other Eleatic philosophers

Leucippus, Democritus and the other Atomists

Protagoras and the Sophists


Socrates (470 B.C. - 399 B.C.), an (Athenian) philosopher, became one of the most important icons of the Western philosophical tradition. His made his most important contribution to Western thought through his method of enquiry. See the article on him for more information.


Plato (c. 427 BC - c. 347 BC), an immensely influential classical Greek philosopher, studied under Socrates and taught Aristotle. His most famous work, The Republic (Greek Politeia, 'city'), outlines his vision of "an ideal" state. He also wrote The Laws and many dialogues featuring Socrates as the main participant. Plato became a pupil of Socrates in his youth, and - at least according to his own account - attended his master's trial, though not his execution. Unlike Socrates, Plato wrote down his philosophical views and left a considerable number of manuscripts. See the article on him for more details.


Aristotle, known as Aristoteles in most languages other than English (Aristotele in Italian), (384 BC - March 7, 322 BC) has, along with Plato, the reputation of one of the two most influential philosophers in Western thought.

Their works, although connected in many fundamental ways, differ considerably in both style and substance. Plato wrote several dozen philsophical dialogues - arguments in the form of conversations, usually with Socrates as a participant - and a few letters. Though the early dialogues deal mainly with methods of acquiring knowledge, and most of the last ones with justice and practical ethics, his most famous works expressed a synoptic view of ethics, metaphysics, reason, knowledge, and human life. Predominant ideas include the notion that knowledge gained through the senses always remains confused and impure, and that the contemplative soul that turns away from the world can acquire "true" knowledge. The soul alone can have knowledge of the Forms, the real essences of things, of which the world we see is but an imperfect copy. Such knowledge has ethical as well as scientific import. One can view Plato, with qualification, as an idealist and a rationalist.

Aristotle, by contrast, placed much more value on knowledge gained from the senses, and would correspondingly better earn the modern label of empiricist. Thus Aristotle set the stage for what would eventually develop into the scientific method centuries later. The works of Aristotle that still exist today appear in treatise form, mostly unpublished by their author. The most important include Physics, Metaphysics, (Nicomachean) Ethics, Politics, De Anima (On the Soul), Poetics, and many others. See the article on Aristotle for more discussion.

Later Classical philosophers


Zeno of Citium


Epicurus and Lucretius


The Neo-Platonists

Ammonius Saccas, Plotinus, Porphyry, Proclus, Iamblichus)

Marcus Aurelius

Schools of thought in the Hellenistic period







The spread of Christianity through the Roman world ushered in the end of the Hellenistic philosophy and the beginnings of Mediaeval Philosophy.

See also: Philosophy, Ancient philosophy