Between the fifteenth and seventeenth centuries, Pythagoras became a purveyor of polite secrets. To the Florentine Neoplatonist philosopher Marsilio Ficino, Pythagoras was a prophet or priest whose cryptic sayings might allow a glimpse into cosmic mysteries. By the 1650s one was as likely to find Pythagoras adorning a treatise on the theory of disciplines like swordsmanship and dancing. Numbers had come down to earth. This paper charts the first, crucial part of this inversion in meanings and importance attributed to Pythagoras—and so to mathematics—among French mathematicians in the first part of the sixteenth century.