Euripidis Tragoediae (Nauck 3rd ed.)

But soon he turned himself to the studies of philosophy and poetry. In philosophy, he used as teachers Anaxagoras of Clazomenae, Prodicus of Ceos, and Protagoras of Abdera: likewise, he seems to have been joined in familiarity with Socrates, from which it came about that there were those who said that Euripides had used the help of Socrates in writing his tragedies 15.

14) Vita Eur. vs. 16: They say he also became a painter and that his small paintings are shown in Megara. Suidas: He was a painter at first.
15) In the life of Eur. to those things which we brought in note 13, these things are appended: Having read or "having turned his mind", he turned to tragedy, and discovered many prologues, physiologies, rhetorics, and recognitions, as having been a student of Anaxagoras, Prodicus, and Protagoras, and a companion of Socrates. It is believed that the philosopher Socrates and Mnesilochus also composed some things with him, as Teleclides says: "That Mnesilochus composes some new Phrygian play of Euripides, and Socrates provides the dry sticks." Others say that Iophon or Timocrates the Argive composed his songs for him. In these, I think "having read" is corrupt; what Thomas Magister substituted, "being quick-witted if anyone was, and having given himself over to tragedy for the sake of labor," reveals an attempt at amending which is not at all probable: "having changed his mind" would have sufficed for the sense, which M. Schmidt conjectured after me in Philol. vol. 18 p. 230. But by an easier mutation, I thought in another edition that "through the years" should be written. Thus you have "after the years" in Zenobius 1.30 p. 11.3 ed. Gott. and in the Scholia of Dosiadas Valck. Diatr. p. 135; Herodotus and Dionysius of Halicarnassus said "through the time," Aristides vol. 1 page 96 said "through the years," and not even now do I disapprove of this suspicion: although L. Dindorf teaches that "to read" sometimes means "to give attention to literature" in Thes. Gr. L. vol. 1, 2 p. 319 D, citing three places from John Malalas, a very poor writer (p. 92.12, p. 352.9, p. 383.6 ed. Bonn). Then "he discovered many prologues" is inept; Thomas Magister p. 139.12 correctly recognized the genuine reading, "he discovered many things, prologues etc.": "For he discovered many things for the art which no one of those before him had." Regarding the fragment of Teleclides, see Meineke's Com. vol. 2 p. 371 sq. with the supplement of Henry Jacobi vol. 5 p. LX. That Euripidean tragedies were called "Socrates-bolted" by Teleclides, which is the common view, is not at all certain: aided by Fritzsche's conjecture in Diog. L. 2.18, I suspect that for "and again Euripides Socrates-bolted" one should write "and again 'Euripide-Socrates-boasters'," with which epithet the comic poet seems to have noted the men of Euripidean and... text cuts off