Pythagoras (570-470 BC) was born on the island colony of Samos. Historian Dr. Martin A. Larson describes him as “A universal genius...He made important contributions to music and astronomy; he was a metaphysician, a natural philosopher, a social revolutionary, a political organizer, and the universal theologian. He was one of those all-embracing intellects which appears at rare intervals.”

Pythagoras’ biographer Diogenes Laertius records that he did not “neglect medicine;” his followers contributed to medical wisdom. In the history of religion, Pythagoras was the first person to teach the concepts of reincarnation, heaven and hell to the Western world.

Diogenes Laertius writes that Pythagoras warned that all who did not accept his teachings would suffer torment in the afterlife, while promising his followers the spiritual kingdom. According to the early Christian father Eusebius: “Pythagoras...declared...that the doctrines which he had received...were a personal revelation to himself from God.”

Pythagoras was driven from his native Samos in 529 BC when the tyrant Polycrates declared him a subversive. He went to Croton in Italy, established a school of philosophy, and lectured to classes of up to six hundred students. He founded a monastic order that soon became very influential. It was basically a religious sect made up of dedicated saints practicing vegetarianism, voluntary poverty and chastity.

In less that two decades, the Pythagoreans were numerous and powerful enough to take political power without having to resort to force or violence. History shows that when the Pythagoreans were attacked and massacred in Magna Grecia in 450 BC, they practiced nonviolence and did not resist their aggressors.

Ancient and modern historians alike acknowledge that Pythagoras was vegetarian. This was the conclusion of Plutarch, Ovid, Diogenes Laertius and Iamblichus in ancient times, and it is the conclusion of scholars today. Nor was vegetarianism loosely connected with the Pythagorean philosophy—it was an integral part of it.

“Oh, my fellow men!” exclaimed Pythagoras. “Do not defile your bodies with sinful foods. We have corn. We have apples bending down the branches with their weight, and grapes swelling on the vines. There are sweet flavored herbs and vegetables which can be cooked and softened over the fire. Nor are you denied milk or thyme-scented honey. The earth affords you a lavish supply of riches, of innocent foods, and offers you banquets that involve no bloodshed or slaughter.”

Pythagoras’ meals consisted of honeycomb, millet or barley bread, and vegetables. He would pay fishermen to throw their catch back into the sea. Ironically, he claimed to have been a fisherman in a previous life. He abhorred animal sacrifice and wine, and would only sacrifice cakes, honey, and frankincense to the gods. He revered the altar at Delos because it was free from blood sacrifices. Upon it, he offered flour, meal, and cakes made without the use of fire. Pythagoras would not associate with cooks or hunters.

According to Iamblichus, Pythagoras taught his followers not to kill even a flea, especially in a temple. He not only showed respect for gods, humans, and animals, but also for the trees, which were not to be destroyed, unless absolutely necessary. It is said Pythagoras pet an eagle, told an ox not to trample a bean field, and fed a ferocious bear barley and acorns, telling it not to attack humans any more.

Pythagoras not only taught transmigration of the soul, or reincarnation, but even claimed to remember his previous lives. It is said Pythagoras once stopped a man from beating a dog, because in the dog’s yelping he recognized the voice of an old friend. For Pythagoras, killing animals for food meant causing suffering or death to living creatures just as worthy of moral concern as human beings, and who may also have been human in previous lifetimes.

If souls can transmigrate from one species to another, and all souls are of the same nature, then the unnecessarily killing animals is as morally indefensible as the unnecessary killing of human beings.

Local tradition says Pythagoras spent time living in a cave on Mount Kerkis in Samos. He was the first person in the history of the world to deduce that the Earth is a sphere. He may have reached this conclusion by comparing the Earth to the Sun and the Moon, or perhaps he noticed the curved shadow of the Earth upon the Moon during a lunar eclipse, or he may have seen that when ships depart and recede over the horizon, their masts disappear last.

The famous “Pythagorean theorem” is now known to have been mathematical knowledge long before Pythagoras. Square roots and cube roots and the “Pythagorean” theorem are mentioned in the Sulbha Sutras of Bodhayana, in India. (700 BC) Bodhayana also calculated the areas of triangles, circles, trapezoids and determined the value of pi = 3.14136 in measuring and constructing temple altars. Some scholars believe Pythagoras may have received his wisdom from the East.

What was significant about Pythagoras’ approach, however, was that he did more than list examples of this theorem: he developed a method of mathematical proof of the theorem, based on deduction. Our modern tradition of mathematical proof, the basis for every kind of science, originated in the West with Pythagoras.

Whereas classical Indian mathematics tended to be intuitive, the Greeks established a tradition of rigorous mathematical proofs. Pythagoras further taught that the world is well-ordered, harmonious, and may be comprehended through human reason. He was the first to use the word “cosmos” to denote a fathomable universe. According to Pythagoras, the laws of nature could be deduced purely by thought.

During the Renaissance and the age of Enlightenment, Kepler and Newton thought of the world in terms of harmony—the order and beauty of planetary motion and the existence of mathematical laws explaining such motion, and from them came our modern scientific belief that the entire universe can be measured, quantified, and explained in terms of mathematical relationships. These ideas began with Pythagoras. "Chemistry is simply numbers,” said Dr. Carl Sagan, “an idea Pythagoras would have liked.”