Pythagoras

Life

Pythagoras grew up on the island of Samos and is said to have travelled to Egypt and Babylon in search of wisdom. Around 530 BC, possibly to escape the tyrant Polycrates, he moved to Croton in southern Italy and founded a community of followers who shared their property, kept strict rules of diet and silence, and studied mathematics, music and the soul. He wrote nothing, and much of what we know about him comes from writers who lived centuries later.

Ideas

The Pythagoreans believed that the universe was ordered by numbers. Pythagoras is credited with discovering that musical harmonies correspond to simple ratios between string lengths, such as 2:1 for the octave. He taught that the soul was immortal and was reborn in new bodies, including those of animals, which is why many of his followers avoided eating meat. The theorem about right-angled triangles bears his name, although the relationship was known in Babylon more than a thousand years earlier.

Legacy

His community became politically powerful in southern Italy and eventually provoked a violent backlash. Yet Pythagorean ideas about mathematics as the key to the cosmos deeply influenced Plato and, through him, the scientists of the Renaissance, including Copernicus and Kepler.