Of Croton (c.470–390 bc) wrote one book, which was probably the first by a Pythagorean (see pythagoras ). He was a contemporary of Socrates and is mentioned in Plato's Phaedo as arguing that suicide is not permissible. Some fragments from his book survive. They show that it was the primary source for Aristotle's account of Pythagoreanism. The book contained a cosmogony and presented astronomical, psychological, and medical theories. Philolaus argued that the cosmos and everything in it was made up not just of the unlimiteds (continua that are in themselves without limit, e.g. earth or void) used as elements by other Presocratics, but also of limiters (things that set limits in a continuum, e.g. shapes). These elements are held together in a harmonia (‘fitting together’) which comes to be in accord with pleasing mathematical relationships. Secure knowledge is possible in so far as we grasp the number in accordance with which things are put together. Philolaus was the first to make the earth a planet. Along with the fixed stars, five planets, sun, moon, and a counter‐earth (thus making the perfect number ten), the earth orbits the central fire.
Subjects: Classical Studies — Philosophy.