Pythagoras c. 570 B.C.–c. 500 B.C.
Although much of his life and thought has been obscured by spurious and often contradictory evidence, Pythagoras is nevertheless considered the most comprehensive of the Presocratic philosophers. A mysterious figure of near legendary status in Greek antiquity, Pythagoras is largely associated with the doctrines of reincarnation and the immortality of the soul. A proponent of Orphic mysticism, Pythagoras observed that the soul experiences continuous cycles of life and death, called transmigration or metempsychosis. He departed somewhat from the Orphies, however, in his belief that purification, or the redemption of the soul, and eventual release from this cycle was attainable through the pursuit of philosophy—the most noble goal of humanity, according to Pythagoras. Additionally, he is sometimes credited with coining the term philosopher, literally a "lover of wisdom," and considered among the first to follow this vocation. A religious leader and scientist as well, Pythagoras and his disciples are also typically associated with various discoveries in the fields of music, mathematics, and astronomy, as well as the conception of cosmic unity which has since become associated with a mathematical ideal of divine perfection—known in the Middle Ages as the musical "harmony of the spheres."
Despite some critical dispute, Pythagoras is said to have been born on the Greek island of Samos in about 570 B.C., the son of a gem engraver named Mnesarchus. Ancient biographers record his youthful travels throughout the Mediterranean region, particularly in Egypt. Shortly after his return to Samos, however, Pythagoras fled his native island to avoid the political despotism of the tyrant Polycrates. By the time he had left Samos in 532 B.C., his reputation as a polymath had spread throughout Magna Graecia and preceded him when he arrived in the Italian city of Croton. Already several legends surrounding Pythagoras had come into common currency, including stories that he had appeared in two places simultaneously, that a river had spoken his name, and that he had a golden thigh. Despite the fantastic nature of these accounts, the fact remains that Pythagoras had earned an almost divine status and employed his considerable fame to establish a religious order and school in Croton. This highly secretive community eventually came to dominate political and social life not only in Croton but throughout southern Italy. The ascendancy of the exclusive Pythagorean sect in the political arena, however, precipitated a growing hostility over the next several decades. An uprising late in the sixth century B.C. forced Pythagoras into exile in Metapontum, where he died in approximately 500 B.C. Still, the Pythagorean order continued to flourish, despite continued clashes, well into the fifth century B.C.; although its political power steadily began to wane. While his school was no longer in existence by 400 B.C., the influence of Pythagoreanism nevertheless survived, appearing in many forms, particularly in the philosophy of Plato and the Neopythagorean philosophical movement which began in the first century A.D. and lasted for more than two centuries.
Largely due to the secretive and mystic nature of the Pythagorean order, Pythagoras produced no written works, relying instead on the oral transmission of his teachings. While the authorship of certain works of poetry—particularly the Golden Verses, a poetic catechism of the order—have been attributed to him by some, these writings were likely drafted by his disciples and successors, many of whom adopted the practice of venerating their teacher by composing works in his name. Still, many of the basic tenets of Pythagorean thought may be discerned in the writings of later Pythagoreans and in the critical commentaries of Pythagoras's contemporaries. Among the most important aspects of Pythagorean thought is the interplay of dual forces, such as those of chaos and order, and the Limited and the Unlimited. According to the cosmology of Pythagoras, all things derive from the actions of the force of limitation on the so-called Unlimited—a chaotic mass that comprises the universe. From these forces arise the possibility of kosmos, or orderly arrangement, and harmonia, or harmony and balance—literally, "fitting together." Pythagoras defined these concepts in terms of mathematics and music, two fields to which he and his disciples made considerable contributions. Musical harmony, Pythagoras discovered, is based upon mathematical principles and proportions. Such practical observations are matched by the religious and mystical elements of Pythagoreanism, many of them concerned with the nature of the soul and the means by which it might achieve perfection. For Pythagoras the soul was immortal and fated to experience multiple lives as it traveled through cycles of life, death, and transmigration (or reincarnation). As a consequence of this belief, Pythagoras preached the kinship of all creatures, each of which possessed a soul. The Pythagorean religion thus prohibited the consumption of meat on the grounds that the animals might contain the souls of those who were once, or in the future would be, human. Release from the cycle of reincarnation could be achieved, however, by sustained contemplation—namely the pursuit of philosophy—which brought about purification of the soul.
Pythagoras seems to have elicited the awe and esteem of many in antiquity and the derision of a select few. A semi-divine figure to some, including Isocrates, who transmits many of the legends surrounding him in his Busiris, Pythagoras has been closely associated with the god Apollo, and tales of his incredible power and wisdom were common. Others, including his contemporary, Heracles, called him a charlatan and a deceiver. Negative assessments formed the minority opinion, however, excepting the weighty conclusions of Aristotle, who revealed many of the more absurd practices of Pythagoras, including his obsession with the spiritual qualities of numbers. Modern criticism has tended to focus on the mass of contradictory evidence concerning the philosopher and the question of his real influence on the development of Greek philosophy. Because of the lack of texts written by Pythagoras himself, scholars have been forced to rely on the documents of such later individuals as Philolaus, a Pythagorean who flourished in the fifth century B.C. and was the first to record the teachings of Pythagoras in written form. Twentieth-century critics have also undertaken the process of separating the scientific and mathematical discoveries that were likely made by later Pythagoreans from the largely spiritual and mystical thought of Pythagoras himself. Most now agree that the main contributions of the philosopher seem to have been in relation to his cosmology—particularly his synthesis of mathematical and musical forms into a theory of divine harmony—and his theory of the soul, which seems not to have existed in Greek thought prior to Pythagoras and which exerted a tremendous influence on later Platonic philosophy.