The Greek philosopher and mathematician Pythagoras, who came up with the Pythagorean theorem, is a bit of a mystery. Everything modern scholars know about the man who started the Pythagorean cult and influenced countless artists was written hundreds of years following his death. In fact, it is unclear whether his famous theorems were actually discovered by him or his followers.
Pythagoras was born on the Greek island of Samos in approximately 570 BCE. After traveling to the Far East and Ancient Egypt, he started teaching people his philosophy and beliefs, which were based on mathematics. His religion became known as Pythagoreanism, and his followers were called mathematikoi. They worshiped mathematical harmonies, believing that everything in the universe, including nature and music, was built on numbers. For example, the number 10 was considered a supreme number. Ten was made by adding 1, 2, 3, and 4 together. These number were called tetractys, and the Pythagoreans prayed and swore oaths to them.
The Pythagoreans settled in Crotona in southern Italy where they made a life for themselves. In general, they were peaceful towards other people as well as animals – though Pythagoras supposedly had some violent tendencies. His strange philosophy impressed his followers so much that they were willing to mutilate themselves to protect his secrets. The Pythagoreans' ideas influenced great thinkers such as Aristotle and Plato, but their lives were undeniably eccentric.
The Pythagoreans believed that rational numbers helped explain the universe. But one member of the cult, Hippasus, came up with the golden ratio. The finding challenged one of the core principals of Pythagoras's work, and the mathematician purportedly killed him.
According to the story, the pair was on a boat together. When Hippasus revealed his contradictory calculations, Pythagoras allegedly pushed him overboard, drowned him, and forced the rest of the cult to keep the incident secret. In another version of the tale, Hippasus was murdered for discovering the square root of two.
Regardless of the truth, that and the discovery of other irrational numbers were a big blow to the Pythagoreans, who were convinced that the universe was created from whole numbers and ratios.
One of the core beliefs of the Pythagorean cult was transmigration of the soul. Transmigration is defined as "the movement of a soul into another body after death." Essentially, they believed in reincarnation; in their minds, the human soul was reborn, sometimes into animals.
This belief may be one of the reasons why the Pythagoreans were vegetarians. The philosopher and mathematician banned his followers from consuming meat. They were also not allowed to eat beans, although it's unclear why. Some say Pythagoras thought men's souls were inside the beans.
The Pythagoreans believed their leader had supernatural powers. They thought he could communicate with animals and remember his previous lives. Pythagoras supposedly knew when an earthquake was about to occur. He was credited with preventing hail from falling and the wind from blowing, as well as having the ability to calm the ocean. It was even rumored that he had a "golden thigh," and that his leg was literally made of gold.
Roman historian Cicero noted that Pythagoreans would defend their ideas by saying, "The Master said so," referring to Pythagoras.
Women were very active in Pythagoreanism, and the mathematician supposedly treated them as equals. Although they were a minority in the cult, Iamblichus listed 218 male Pythagoreans and 17 Pythagorean women in his writing On the Pythagorean Life. It's unclear whether these women were part of the sixth, fifth or fourth century Pythagorean cult.
One of the more famous women was named Theano. She is referenced as the wife of Brontinus but also as either the wife, daughter, or student of Pythagoras himself. Several works were forged in her name.
Another famous female Pythagorean is Timycha. Allegedly, she was 10 months pregnant when she bit off her tongue to prevent herself from revealing Pythagorean secrets to Dionysius under duress.