Pythagoras

Pythagoras of Samos (c. 570 – 495 BCE) is at once one of the most famous and
one of the most elusive figures of early Greek thought. He left no writings,
and the brotherhood he founded shrouded his teachings in secrecy, so that
within a generation the man had merged with legend. Even in antiquity it was
difficult to distinguish the historical Pythagoras from the marvels and
doctrines later ascribed to him.

Around 530 BCE Pythagoras emigrated from Samos to Croton in southern Italy,
where he established a community that was at once a philosophical school, a
religious order, and a political force. Its members followed a strict
discipline of communal life, dietary restriction, self-examination, and
silence, bound together by a shared way of life as much as by shared
doctrine. The Pythagoreans exerted considerable influence over the cities of
the region until a violent backlash scattered them.

At the heart of Pythagorean thought lay the conviction that number is the key
to reality. The discovery that the concordant intervals of music — the
octave, the fifth, the fourth — correspond to simple whole-number ratios of
string length seemed to reveal a mathematical order underlying the sensible
world. From this the Pythagoreans extended numerical harmony to the cosmos
itself, imagining the heavenly bodies moving in proportions that produced an
inaudible "music of the spheres." The theorem about right triangles that
bears Pythagoras' name belongs to this tradition, though its attribution to
the man himself is uncertain.

Bound up with this mathematical vision was a religious doctrine of the soul.
The Pythagoreans believed in metempsychosis, the transmigration of the soul
through successive bodies, human and animal alike. The soul was a fallen,
immortal thing, and the purpose of their discipline — including the famous
abstention from meat and beans — was its purification and eventual release
from the cycle of rebirth. Philosophy, on this view, was a way of life aimed
at the soul's salvation.

The Pythagorean fusion of mathematics, music, and mysticism left a deep mark
on Plato, whose later cosmology is steeped in number and proportion, and
through him on the entire Western tradition. The very word "philosophy,"
meaning love of wisdom, was attributed by ancient writers to Pythagoras
himself.