Pythagoras must have been one of the world's greatest men. However, he wrote nothing and it is unknown how much of the doctrine of Pythagoras is due to the founder of society and how much is later development. Sometimes he is represented as a man of science, a mathematician, and even as a preacher of mystical doctrines. None of these traditional views, however, should be rejected, for he contributed his genius in each field.
Pythagoras lived from about 569 BC to about 475 BC. His father was Mnesarchus, a merchant from Tyre; his mother was Pythais, a native of Samos. Pythagoras spent most of his early years in Samos but traveled with his father. He was taught by the Chaldeans and the learned men of Syria. Among his teachers, there were three philosophers who influenced Pythagoras while he was a young man, Pherekydes, Thales, and Aleximander. They influenced Pythagoras' interest in geometry and cosmology, encouraging him to pursue his studies in Egypt. In 535 BC, Pythagoras went to Egypt where he visited many temples and took part in many discussions with priests. Then, after his journeys to Samos and Crete, Pythagoras founded a philosophical and religious school in Crotona. He was the head of the society with an inner circle of followers known as mathematikoi.Pythagoras influenced a group of early Greek scientific and religious thinkers, the Pythagoreans. They believed that the soul was immortal and separable from the body. Because they believed that the soul was reincarnated in different animal bodies, they practiced vegetarianism. The group was almost cult-like in that it had symbols, rituals and prayers. In addition, Pythagoras believed that "Number rules the universe," and the Pythagoreans gave numerical values to many objects and ideas. These numerical values, in turn, were endowed with mystical and spiritual qualities.
The Pythagoreans discovered irrational numbers. If an isosceles right triangle is taken with legs of measure 1, the hypotenuse