Theudius

Theudius is a Greek mathematician of IV century BCE, born in Magnesia, a member of the Platonic Academy and a contemporary of Aristotle. He is only known from Proclus’ commentary to Euclid, where Theudius is said to have had “a reputation for excellence in mathematics as in the rest of philosophy, for he produced admirable "Elements" and made many partial theorems more general” [Proclus. A Commentary on the First Book of Euclid’s Elements. Translated with an Introduction and Notes by G. R. Morrow. 1970 (repr. Princeton: Princeton University Press, 1992)] .

The "Elements" of Theudius are probably the source for Aristotle’s mathematical examples.

Sources

See also: Proclus. In primum Euclidis Elemetorum librum commentarii. Ed. G. Friedlein. Leipzig, 1873, 67.12-16).