Library Hippolytus Refutation of All Heresies
Book 1
Chapter 15: Socrates; His Philosophy Reproduced by Plato
Socrates, then, was a hearer of Archelaus, the natural philosopher; and he, reverencing the rule, Know yourself,
and having assembled a large school, had Plato (there), who was far superior to all his pupils. (Socrates) himself left no writings after him. Plato, however, taking notes of all his (lectures on) wisdom, established a school, combining together natural, ethical, (and) logical (philosophy). But the points Plato determined are these following.
English translation by J.H. MacMahon, in Ante-Nicene Fathers, Vol. V (eds. Alexander Roberts and James Donaldson; Buffalo: Christian Literature Publishing Co., 1886). Public domain. Digital text via New Advent Church Fathers.