While some claim the same for Thales, some believe Pythagoras was the first philosopher.
Pythagoras believed math helps us understand reality. His influence in this area was great. Pythagoras founded geometry and is also known as the founder of the Pythagorean Theorem.
Pythagoras is also famous for his religious beliefs and actions. He founded a religious community in which the eating of beans was prohibited.
He also believed the souls of people could migrate to animals at death. Thus he held to the view of the transmigration of the soul. In fact, Pythagoras once stopped a man from beating a puppy because he thought he heard the voice of a departed friend in the puppy’s whimper.