Against Celsus 3.13

If this is consistent, how shall we not make the same defense concerning the heresies among Christians? About them Paul seems to me to have said, very wonderfully: “For there must also be heresies among you, so that those who are approved may become manifest (among you).” For just as he is approved in medicine who, having trained himself in various schools and examined most of them fairly, has chosen the best; and as the one who makes great progress in philosophy is he who, by knowing more of them, has trained himself in them and attached himself to the prevailing doctrine; so I would say that one who has carefully examined the sects of Judaism and Christianity becomes a very wise Christian. And one who accuses the teaching because of the heresies would also accuse the teaching of Socrates, from whose school many schools of people not holding the same views have come; and one might also accuse the doctrines of Plato because of Aristotle, who left his school with innovations, of whom we have spoken above. It seems to me that Celsus has known certain heresies that do not even share the name of Jesus with us. Perhaps he had heard of the so-called Ophites and Cainites, or any other such opinion that has arisen, having departed from Jesus altogether. But this has nothing to do with the Christian teaching being blameworthy.