10 Strange Facts About Pythagoras: Mathematician and Cult Leader

Pythagoras, the man behind the Pythagorean theorem, was more than just a mathematician. He was a spiritual leader with followers who thought he’d been sent from Heaven. For the Pythagoreans, math was a religious experience, and some equations were divine secrets, unfit for public eyes.

When your middle school teacher showed you how to find the hypotenuse of a right triangle, you probably didn’t get down on your knees and start worshiping him as a god. But when it first happened in ancient Greece, that was pretty much how people reacted.

There was a whole cult behind the man who figured out how to measure the side of a triangle, and—as you might imagine—they had some pretty strange beliefs.

10 Pythagoras Led a Cult That Worshiped Numbers

Pythagoras had followers. A whole group of mathematicians signed up to be his pupils, to learn everything he knew, and to help him solve the great riddles of the universe. But this was more than just a group of people who liked math—it was a full-blown religion.

Numbers, Pythagoras believed, were the elements behind the entire universe. He taught his followers that the world was controlled by mathematical harmonies that made up every part of reality. More than that, though, these numbers were sacred—almost like gods.

The Pythagoreans had sacred numbers. Seven was the number of wisdom, 8 was the number of justice, and 10 was the most sacred number of all. Every part of math was holy. When they solved a new mathematical theorem, they would give thanks to the gods by sacrificing an ox.^[1]

The Greeks thought it was a little freaky. They didn’t just call it a philosophy or a religion—they saw it as a cult and a dangerous one at that. Pythagoras scared people. They even burned down his house and chased him out of town, fearing his mystic command over the sacredness of numbers.

9 They Prayed to the Number 10

The Pythagoreans had a sacred symbol called the Tetractys. It was a triangle with 10 points across four rows, meant to symbolize the organization of space and the universe. Ten, they believed, was the number of the highest order, which contained the course of all mortal things. And they literally worshiped it.

Pythagoras’s followers had a set prayer they used to worship the number 10. “Bless us, divine number, thou who generated gods and men!” they would say. “For the divine number begins with the profound, pure unity until it comes to the holy four; then it begets the mother of all, the all-comprising, all-bounding, the firstborn, the never-swerving, the never-tiring holy ten, the keyholder of all.”^[2]

Everyone had to do it. If you wanted to join the Pythagoreans, you had to swear an oath to the holy triangle. They would swear their loyalty “by that pure, holy, four-lettered name on high,” meaning the Tetractys. Then they would have to swear by Pythagoras himself, who, like a mathematical Prometheus, “to our mortal race did bring the Tetractys.”

8 Pythagoras Was Treated Like a God

Pythagoras’s followers really believed that he was a demigod. They called him “the divine Pythagoras” and told people that he was the son of a god—usually either Hermes or Apollo, depending on whom you asked.

They even had hymns to Pythagoras’s divinity. “Pythais, fairest of the Samian tribe,” one song went, “Bore from th’ embraces of the God of Day. Renown’d Pythagoras, the friend of Jove!”

They even thought that Pythagoras had superpowers. His followers said that he could tame eagles and bears by stroking them. He could control any animal, for that matter, with the sheer power of his voice, and he had the power to write words on the face of the Moon.

One of the biggest legends about him was that he had a golden thigh. When someone doubted his divinity, it was said that Pythagoras would show them his shimmering thigh and win a new convert. In one story, he showed a priest his thigh and, as a reward, was given a magical golden dart that let him fly over mountains, expel diseases, and calm storms.^[3]

7 He Told People He Would Be Reborn After Death

It wasn’t that people just got so swept up in the hypotenuse-finding craze that they started making up stories about Pythagoras—he encouraged them. Pythagoras directly told people that he was the son of a god and that he had been repeatedly reincarnated until he reached his current form.

In a past life, Pythagoras claimed, he was the son of Hermes, who had offered Pythagoras any gift he wanted except for immortality. Pythagoras asked to retain his memories through each life and now could remember every person he had ever been. He had fought with Achilles in the Trojan War. He had worked as a humble fisherman. He had even been a beautiful courtesan who slept with powerful men.

More than that, though, Pythagoras claimed that he could sense old souls in new bodies. Legend has it that he once saw a dog getting beaten on the streets and ran in the way to stop the blows. “Stop! Don’t beat it!” Pythagoras yelled. “It is the soul of a friend.” He had recognized its voice in the dog’s barking.^[4]

6 He Was One of the Earliest and Laziest Vegetarians

Pythagoras was one of the first people in Western history to abstain from eating meat for moral reasons. Eating the dead, he taught his followers, polluted the body—and so they must never kill a living thing.

His rules were a bit weird, though. You might remember that we mentioned earlier his sacrifice of oxen—and, yes, he did both. Like a vegan who eats fish and chicken, Pythagorean vegetarianism had some weird loopholes.

”The offerings he made were always inanimate,” the Greek writer Diogenes wrote in a biography of Pythagoras. Then Diogenes clarified: “Though some say that he would offer cocks, sucking goats, and porkers.” Still, Pythagoras drew the line somewhere. “But lambs,” Diogenes explained, “Never!”^[5]

Pythagoras’s rules seemed every bit as weird to the Greeks as they do to us. During his time, the Greeks spread a joke about a Pythagorean who insisted that he never ate any living thing. After getting caught eating dog meat, the Pythagorean said, “Yes, but [I kill] them first, and so they are still not alive.”

5 He Had Rules for Everything

The Pythagoreans might have had loopholes for meat, but that didn’t mean they could do whatever they wanted. Pythagoras had some incredibly strict and specific rules for just about everything—including which shoe to put on first.

“One must put the right shoe on first,” Pythagoras told his followers. And once your shoes were on, he said, “One must not travel on public roads.” He didn’t stop at footwear, though. Pythagoras weighed in on the five-second rule for food that falls on the floor, telling his followers never to “taste ye of what falls beneath the board.” One could not stir the fire with iron nor break bread. Oh, and always make your bed, “When you rise from the bedclothes, roll them together and smooth out the impress of the body.”

He was exceptionally strict about sex. Bodily fluids, Pythagoras seems to have believed, were part of a man’s soul. When a man expelled them, he gave up some of his strength. Pythagoras’s followers were taught to abstain from sex whenever possible. But if they couldn’t help themselves, he told them: Keep to the winter for sexual pleasures, in summer, abstain.”^[6]

4 New Initiates Had to Spend Five Years in Silence

Silence, Pythagoras believed, was very important. Staying quiet was a way to learn self-control, so he made sure that anyone who wanted to join his cult could do it. Anyone who signed up had to close his mouth and keep it shut for five years straight.

In part, this was to help people stay pure. But there’s a lot of reason to believe that it had more to do with making sure they could keep secrets. Even in ancient Greece, calling yourself the son of god and getting people to worship numbers wasn’t exactly considered being a model citizen.

The Pythagoreans tried to keep that part of their lives quiet. As a result, they wouldn’t let anyone into the fold unless they proved that he could keep his mouth shut.

Most of the Greeks, though, didn’t understand the dark implications of these silent acolytes. The Greeks were just happy that a Pythagorean wasn’t going on about numbers for a change. Generally, people were more impressed by the quiet ones than the people who were allowed to talk.^[7]

3 He May Have Drowned a Man for Discovering Irrational Numbers

One of Pythagoras’s most famous followers was Hippasus. Legend has it that he was the first person to prove the existence of an irrational number—and he may have died for it.

Hippasus developed a proof that showed that the square root of two was an irrational, never-ending number. This was more than just a major discovery—it was open rebellion. Pythagoras had taught that all numbers could be expressed as ratios of integers, and Hippasus had proven his divine teacher wrong.

According to the legend, Hippasus showed his proof to Pythagoras while they were on a boat. In response, Pythagoras grabbed Hippasus, wrestled him to the side of the boat, and held his head underwater until he stopped moving. Then Pythagoras threw the lifeless body overboard, turned to the others aboard, and warned them never to tell a soul what had happened.^[8]

That story is probably not true. It seems to be a twisted version of a Pythagorean fable that said the gods drowned Hippasus as punishment for disclosing the secret of irrational numbers to the world.

But that story still reveals something creepy about the Pythagorean cult. They spread this story, it’s believed, as a parable—a warning telling their followers that if they shared the cult’s secrets with the world, they could expect a watery grave.

2 He Gave Speeches Behind a Curtain

There were two types of Pythagoreans: the akousmatikoi and the mathematikoi. The mathematikoi were Pythagoras’s closest and most trusted followers. He would meet with them in person and explain his theorems to them in detail. They were allowed to know the secrets of advanced math kept hidden from the rest of the world.

They had to pay a heavy price for the privilege. To become a mathematikoi, a person had to give up meat, women, and private possessions. From then on, their only loyalty was to Pythagoras.

The rest were allowed to be akousmatikoi—followers who were never allowed to see Pythagoras’s face. When he spoke to them, Pythagoras would be hidden behind a veil like the Wizard of Oz. Nothing was explained to the akousmatikoi in any detail. They were merely expected to follow his rituals. They could not be trusted with the dangerous secrets of higher mathematics.^[9]

1 He Gave Up His Life to Protect Fava Beans

One of Pythagoras’s strangest rules was that his followers were never to touch fava beans. Beans, he taught, took away a piece of the soul. “They are flatulent,” he explained. When that gas came out, it would “partake most of the breath of life.”

There may have been more to it than just that. It’s claimed that he believed beans contained the souls of the dead and told his followers, “Eating fava beans and gnawing on the heads of one’s parents are one and the same.”

Beans were so sacred to the Pythagoreans that, in the end, Pythagoras gave his own life to protect them. According to one story, Pythagoras met his end when a man, furious that he couldn’t see Pythagoras’s face, burned Pythagoras’s house to the ground.

Pythagoras had to run for his life but stopped before a field of beans. He would rather die, he declared, than step on a single bean. He let the men cut his throat so that the beans could live.^[1]

Of course, that’s just one of many stories about his death. But almost all of them end with Pythagoras giving his life for a bean field. In some stories, he gets attacked for trying to overthrow the government. In others, he gets burned at a stake. But in nearly every one, Pythagoras meets his end by choosing to give up his own life so that he doesn’t have to trample on beans.