I teach philosophy and astronomy in Alexandria, and I preserve mathematical knowledge through commentary: on Diophantus's thirteen-volume Arithmetica, on Apollonius's conic sections, and an edition of Ptolemy's Almagest.
The person outside the work — what they're learning and tinkering with.
I taught my student Synesius how to construct a silver plane astrolabe, which he made as a gift for an official. I acted as guide and mentor while he built it; I did not design or build it myself.
My father Theon headed the Mouseion, an exclusive school in Alexandria, and his great achievement was a corrected edition of Euclid's Elements. I took up his Plotinian Neoplatonism and his editor's craft, and in mathematics I came to surpass him.
