Proclus

Proclus credits Pythagoras, for example, with discovering the theorem we now call Pythagoras’s theorem, and Menelaus the theorem that is the mathematical foundation for Ptolemaic astronomy.

Had Vergil had an opportunity to read Proclus, some of this might have made its way into his text, but it is unlikely that he would have absorbed the concept of discovery.

It was quickly followed by Francesco Barozzi’s 1560 translation of Proclus’s commentary on the first book of Euclid, which presented the history of mathematics in terms of a series of inventions or discoveries.

The Platonists’ doctrines of recurrence and reminiscence were not the real problem, however; both were endorsed by Proclus, who still wrote, as the Greeks did, in terms of discovery.

Even if we do want accept the postulate without proof, Proclus would prefer that we call it an axiom, rather than a postulate.