From Justin Martyr’s Dialogue with Trypho:

Being at first desirous of personally conversing with one of these men, I surrendered myself to a certain Stoic; and having spent a considerable time with him, when I had not acquired any further knowledge of God (for he did not know himself, and said such instruction was unnecessary), I left him and betook myself to another, who was called a Peripatetic, and as he fancied, shrewd. And this man, after having entertained me for the first few days, requested me to settle the fee, in order that our intercourse might not be unprofitable. Him, too, for this reason I abandoned, believing him to be no philosopher at all. But when my soul was eagerly desirous to hear the peculiar and choice philosophy, I came to a Pythagorean, very celebrated–a man who thought much of his own wisdom. And then, when I had an interview with him, willing to become his hearer and disciple, he said, ‘What then? Are you acquainted with music, astronomy, and geometry? Do you expect to perceive any of those things which conduce to a happy life, if you have not been first informed on those points which wean the soul from sensible objects, and render it fitted for objects which appertain to the mind, so that it can contemplate that which is honourable in its essence and that which is good in its essence?’ Having commended many of these branches of learning, and telling me that they were necessary, he dismissed me when I confessed to him my ignorance. Accordingly I took it rather impatiently, as was to be expected when I failed in my hope, the more so because I deemed the man had some knowledge; but reflecting again on the space of time during which I would have to linger over those branches of learning, I was not able to endure longer procrastination. In my helpless condition it occurred to me to have a meeting with the Platonists, for their fame was great. I thereupon spent as much of my time as possible with one who had lately settled in our city,–a sagacious man, holding a high position among the Platonists,–and I progressed, and made the greatest improvements daily. And the perception of immaterial things quite overpowered me, and the contemplation of ideas furnished my mind with wings, so that in a little while I supposed that I had become wise; and such was my stupidity, I expected forthwith to look upon God, for this is the end of Plato’s philosophy.