The only thing most people know about Pythagoras is that he created the Pythagorean Theorem…which he may not have actually created. In fact, he might not have existed at all.
But Pythagoras did have a large religious following during his (or its) time. His followers mostly resembled a dirty hippie-like commune, yet they did leave behind a lasting legacy: the significance of numbers in the universe and the idea of souls being immortal…and having the possibility of transmigrating.
It’s important to not get Euro-centric here. Ideas of reincarnation were probably influenced from somewhere else outside of Ancient Greece. Herodotus claimed that the Egyptians held similar beliefs, and this might’ve been where Pythagoras picked it up. There’s a lot of evidence that contradict this, but it goes to show how ideas went back and forth in the ancient world…perhaps WAY more than we realize. Religious and philosophical influences in Ancient Greece may have found their origin in Persia, India, Egypt, etc…and vice-versa. “The Axial Age”, as some academics call this time period, saw the rise of similar religions and philosophies across the world, and that is definitely not a coincidence.
But in the Hellenized world during the time of Pythagoras, Homer dominated religious thought. In Homer’s works, the afterlife was presented as a much darker experience, one where life is much more preferable (I believe the Epic of Gilgamesh held similar views, but correct me if I’m wrong). This concept of the immortal soul presented by the Pythagoreans would have provided a much welcomed change towards the approach of death.
This is significant because this seems to indicate a mind-body dualism. While I couldn’t find any evidence of Pythagoreanism being the first to present the mind-body problem in Ancient Greece, it does introduce an interesting question…perhaps planting the seed for what would later become this (mostly false) philosophical problem. Nevertheless, Pythagoreanism seemed to have echoed several Eastern religions in presenting an “eternal recurrence” conception, where the universe repeats itself.
What is less clear, however, is if Pythagoras believed that there was a way to “break” this cycle.
But what Pythagoras and his followers are known for today is the high importance they placed on math. As I mentioned earlier, there’s no evidence that Pythagoras actually discovered the theorem named after him. At best, as some evidence indicates, he picked it up from the Babylonians and brought it to Greece. In fact, there’s no evidence that he discovered ANY mathematical principle. All that can really be said is Pythagoras possibly picked up on the importance of geometrical structures and incorporated it into his discipline.
Still though, that’s saying a lot. Many later scientists and mathematicians would follow Pythagoras’ lead, namely Johannes Kepler, Galileo Galilei, and Gottfried Leibniz.
But in my view, Pythagoras and his followers should be most celebrated for their (mostly) progressive ways. It is here where Plato likely found the inspiration for his Republic (Bertrand Russell would later claim that Plato owed a great deal of his philosophy to Pythagoras). Yet most importantly is his views on women should be commended. According to Diogenes Laertius, the priestess Themistoclea taught Pythagoras his moral education. While some of his views were a bit out there, many of his followers were some the first women philosophers. This is also why we have every right to judge Aristotle’s views on women, as those before him had far more progressive views.
Unfortunately, most of things we can say about Pythagoras is speculative. But what we do know is that his followers were new age dirty hippies long before there were new age dirty hippies.