12 Since, then, I have so often reminded my reader of my views; and since I have picked my way like a prudent traveller over every inch of the road, stating repeatedly that, while I receive marriage as a thing in itself admissible, I yet prefer continence, widowhood, and virginity, the wise and generous reader ought to have judged what seemed hard sayings by my general drift, and not to have charged me with putting forward inconsistent opinions in one and the same book. For who is so dull or so inexperienced in writing as to praise and to condemn one and the same object, as to destroy what he has built up, and to build up what he has destroyed; and when he has vanquished his opponent, to turn his sword, last of all against himself? Were my detractors country bred or unacquainted with the arts of rhetoric or of logic, I should pardon their want of insight; nor should I censure them for accusing me if I saw that their ignorance was in fault and not their will. As it is men of intellect who have enjoyed a liberal education make it their object less to understand me than to wound me, and for such I have this short answer, that they should correct my faults and not merely censure me for them. The lists are open, I cry; your enemy has marshalled his forces, his position is plain, and (if I may quote Virgil)—
The foeman calls you: meet him face to face.
Such men should answer their opponent. They ought to keep within the limits of debate, and not to wield the schoolmaster's rod. Their books should aim at showing in what my statements have fallen short of the truth, and in what they have exceeded it. For, although I will not listen to fault-finders, I will follow the advice of teachers. To direct the fighter how to fight when you yourself occupy a post of vantage on the wall is a kind of teaching that does not commend itself; and when you are yourself bathed in perfumes, it is unworthy to charge a bleeding soldier with cowardice. Nor in saying this do I lay myself open to a charge of boasting that while others have slept I only have entered the lists. My meaning simply is that men who have seen me wounded in this warfare may possibly be a little too cautious in their methods of fighting. I would not have you engage in an encounter in which you will have nothing to do but to protect yourself, your right hand remaining motionless while your left manages your shield. You must either strike or fall. I cannot account you a victor unless I see your opponent put to the sword.
Source: Letters (New Advent)