Something unusual happened in Greece and in the Greek colonies of the Aegean Sea some twenty-five hundred years ago. Whereas the previous great cultures of the Mediterranean had used mythological stories of the gods to explain the operations of the world and of the self, some of the Greeks began to discover new ways of explaining these phenomena. Instead of reading their ideas into, or out of, ancient scriptures or poems, they began to use reason, contemplation, and sensory observation to make sense of reality. The story as we know it began with the Greeks living on the coast of Asia Minor (present-day Turkey). Colonists there, such as Thales, tried to find the one common element in the diversity of nature. Subsequent thinkers, such as Anaximenes, sought not only to find this one common element, but also to find the process by which one form changes into another. Other thinkers, such as Pythagoras, turned to the nature of form itself rather than the basic stuff that takes on a particular form. With Socrates, the pursuit of knowledge turned inward as he sought not to understand the world, but himself. His call to “know thyself,” together with his uncompromising search for truth, inspired generations of thinkers. With the writings of Plato and Aristotle, ancient Greek thought reached its zenith. These giants of human thought developed all-embracing systems that explained both the nature of the universe and the humans who inhabit it. All these lovers of wisdom, or philosophers, came to different conclusions and often spoke disrespectfully of one another. Some held the universe to be one single entity, whereas others insisted that it must be made of many parts. Some believed that human knowledge was capable of understanding virtually everything about the world and the self, whereas others thought that it was not possible to have any knowledge at all. But despite all their differences, there is a thread of continuity, a continuing focus among them: the human attempt to understand the world and the self, using human reason. This fact distinguishes these philosophers from the great minds that preceded them. The philosophers of ancient Greece have fascinated thinking persons for centuries, and their writings have been one of the key influences on the development of Western civilization. The works of Plato and Aristotle, especially, have defined the questions and suggested many of the answers for subsequent generations. As the great Greek statesman Pericles sagely predicted, “Future ages will wonder at us, as the present age wonders at us now.” * * * For a comprehensive, yet readable, work on Greek philosophy, see W.K.C. Guthrie’s authoritative The History of Greek Philosophy, six volumes. (Cambridge: Cambridge University Press, 1962–1981). W.T. Jones, The Classical Mind (New York: Harcourt, Brace & World, 1969); Frederick Copleston, A History of Philosophy: Volume I, Greece & Rome (Garden City, NY: Doubleday, 1962); Friedo Ricken, Philosophy of the Ancients, translated by Eric Watkins (Notre Dame, IN: University of Notre Dame Press, 1991); J.V. Luce, An Introduction to Greek Philosophy (New York: Thames and Hudson, 1992); C.C.W. Taylor, ed., Routledge History of Philosophy, Volume 1: From the Beginning to Plato (London: Routledge, 1997); David Furley, ed., Routledge History of Philosophy, Volume 2: Aristotle to Augustine (London: Routledge, 1997); Julia Annas, Ancient Philosophy: A Very Short Introduction (Oxford: Oxford University Press, 2000); James A. Arieti, Philosophy in the Ancient World (Lanham, MD: Rowman & Littlefield, 2005); Anthony Kenny, Ancient Philosophy: A New History of Western Philosophy (Oxford University Press, 2004); and Stephanie Lynn Budin, The Ancient Greeks: An Introduction (Oxford: Oxford University Press, 2009) provide basic introductions. Julie K. Ward, ed., Feminism and Ancient Philosophy (London: Routledge, 1996) provides a feminist critique while Robert S. Brumbaugh, The Philosophers of Greece (Albany, NY: SUNY Press, 1981) is an accessible introduction with pictures, charts, and maps.