9 Then come the words “But I say to the unmarried and to widows, it is good for them if they abide even as I. But if they have not continency, let them marry: for it is better to marry than to burn.” Having conceded to married persons the enjoyment of wedlock and pointed out his own wishes, he passes on to the unmarried and to widows, sets before them his own practice for imitation, and calls them happy if they so abide. “But if they have not continency, let them marry,” just as he said before “But because of fornications,” and “Lest Satan tempt you, because of your incontinency.”
And he gives a reason for saying “If they have not continency, let them marry,” viz. “It is better to marry than to burn.” The reason why it is better to marry is that it is worse to burn. Let burning lust be absent, and he will not say it is better to marry. The word better always implies a comparison with something worse, not a thing absolutely good and incapable of comparison. It is as though he said, it is better to have one eye than neither, it is better to stand on one foot and to support the rest of the body with a stick, than to crawl with broken legs.
What do you say, Apostle? I do not believe you when you say “Though I be rude in speech, yet am I not in knowledge.” As humility is the source of the sayings “For I am not worthy to be called an Apostle,” and “To me who am the least of the Apostles,” and “As to one born out of due time,” so here also we have an utterance of humility. You know the meaning of language, or you would not quote Epimenides, Menander, and Aratus. When you are discussing continence and virginity you say, “It is good for a man not to touch a woman.”
And, “It is good for them if they abide even as I.” And, “I think that this is good by reason of the present distress.” And, “That it is good for a man so to be.” When you come to marriage, you do not say it is good to marry, because you cannot then add “than to burn;” but you say, “It is better to marry than to burn.” If marriage in itself be good, do not compare it with fire, but simply say “It is good to marry.” I suspect the goodness of that thing which is forced into the position of being only the lesser of two evils. What I want is not a smaller evil, but a thing absolutely good.
Source: Against Jovinianus (New Advent)