Pythagoras of Samos
Pythagoras was influenced by oriental thought and especially oriental mysticism. He wrote nothing but most of his radical thinking survived in the writings of his students Philolaus, Archytas and Alcmaeon. Pythagoras’ ideas was also influential in Plato and later Platonism. Important stories about his life and activities, but dubious most of them, are presented in the Neoplatonic biographies of Porphyry and Iamblichus.
The other two philosophers who were to influence Pythagoras, and to introduce him to mathematical ideas, were Thales and his pupil Anaximander who both lived on Miletus. It is said that Pythagoras visited Thales in Miletus when he was between 18 and 20 years old. By this time Thales was an old man and, although he created a strong impression on Pythagoras, he probably did not teach him a great deal.
However he did contribute to Pythagoras's interest in mathematics and astronomy, and advised him to travel to Egypt to learn more of these subjects. Thales's pupil, Anaximander, lectured on Miletus and Pythagoras attended these lectures. Anaximander certainly was interested in geometry and cosmology and many of his ideas would influence Pythagoras's own views.
Of course today we particularly remember Pythagoras for his famous geometry theorem. Although the theorem, now known as Pythagoras's theorem, was known to the Babylonians 1000 years earlier; he may have been the first to prove it.
Primarily, however, Pythagoras was a philosopher. In addition to his beliefs about numbers, geometry and astronomy.
He died on 495 BC, in Metapontum.