Philolaus of Croton (a Greek city in southern Italy) was a philosopher/scientist in the Pythagorean tradition. He was a contemporary of Socrates, being born c. 470 BCE, twenty years after Pythagoras died, and living until c. 385. On his first trip to Italy, Plato may have met an aged Philolaus; he mentions him as a teacher of the Thebans Simmias and Cebes in the Phaedo. A large body of pseudo-Pythagorean writings appeared in the first century BCE, and a number of these were forged in Philolaus's name, because he was one of the three most famous early Pythagoreans (along with Pythagoras himself and Archytas). Some fifteen fragments and a number of testimonia survive from these forged works. Philolaus, in fact, wrote one book, On Nature, which was probably the first book in the Pythagorean tradition (Pythagoras wrote nothing). Approximately...