There is, famously, no text that goes back to Pythagoras himself, but there were many self-identified Pythagoreans of later times who made a record of what they understood to be its ethical principles. Some of these are eccentric, but they were also widely used for ethical instruction by people who did not follow the specifically Pythagoric rules (like abstaining from beans).
- The Golden Verses, a beautiful poem that includes both moral commandments and excellent advice for putting them into practice. It promises those who follow it well divinization after death.
- Pythagoras’ Advice to his Students is a similar text in prose, apparently based on the Golden Verses in part, but also with some interesting additional rules.
- The Symbols of Pythagoras, that is, a number of injunctions that were thought to have a metaphorical philosophical meaning.
- Iamblichus on Pythagoric Symbols [Work in Progress].
Also see the Pythagoric Handbooks for their teachings beyond ethical maxims.