Nicene and Post-Nicene Fathers, Ser. II, Vol. III:
Life and Works of Rufinus with Jerome's Apology Against Rufinus.: He confesses his obligations to Porphyry.

9. When he wrote his treatises against Jovinian, and some one had raised objections to them, he was informed of these objections by Domnio, that old man whose memory we all revere; and in his answer to him 2949 he said that it was impossible that a man like him should be in the wrong, since his knowledge extended to everything that could be known: and he proceeded to enumerate the various kinds of syllogisms, and the whole art of learning and of writing (of course supposing that the man who found fault with him knew nothing about such things). He then goes on thus: 2950

“It was foolish, it appears, in me to think that I could not know all these things without the philosophers, and to look upon the end of the stylus which strikes out and corrects as better than the end with which we write. It was useless for me it seems, to have translated 2951 the Commentaries of Alexander, and for my learned master to have brought me into the knowledge of Logic through the ‘Introduction’ of Porphyry; and, putting aside humanistic teachers, there was no reason why I should have had Gregory Nazianzen and Didymus as my teachers in the Scriptures.”

This, you observe, is the man who said to Christ, I have denied thee if ever I am found to possess or to read the works of the heathen. He might, one would think, at all events have left out Porphyry, who was Christ’s special enemy, who endeavoured as far as in him lay to completely subvert the Christian religion, but whom he now glories in having had as his instructor in his Introduction to Logic. He cannot put in the plea that he had learned these things at a former time: for, before his conversion, he and I equally were wholly ignorant of the Greek language and literature. All these things came after his oath, after that solemn engagement had been made. It is of no use for us to argue in such a case. It will at once be said to us: Man, you are wrong, God is not mocked, and no syllogisms spun out of the books of Alexander will avail with him. I think, my brother, it was an ill-omened event that you submitted to the Introduction of Porphyry. Into what has that faithless man introduced you? If it is into the place where he is now, that is the place where there is weeping and gnashing of teeth; for there dwell the apostate and the enemies of God; and perhaps the perjurers will go there too.

Footnotes

Ep. 1.

Ep. l. 1.

Verti. Possibly used like Versare for ‘turning over the leaves,’ ‘making constant use of.’