3 Wherefore, as I have already written, either send me the identical letter in question subscribed with your own hand, or desist from annoying an old man, who seeks retirement in his monastic cell. If you wish to exercise or display your learning, choose as your antagonists, young, eloquent, and illustrious men, of whom it is said that many are found in Rome, who may be neither unable nor afraid to meet you, and to enter the lists with a bishop in debates concerning the Sacred Scriptures. As for me, a soldier once, but a retired veteran now, it becomes me rather to applaud the victories won by you and others, than with my worn-out body to take part in the conflict; beware lest, if you persist in demanding a reply, I call to mind the history of the way in which Quintus Maximus by his patience defeated Hannibal, who was, in the pride of youth, confident of success.
Omnia fert ætas, animum quoque. Sæpe ego longos
Cantando puerum memini me condere soles;
Nunc oblita mihi tot carmina: vox quoque Mœrin
Jam fugit ipsa.
Or rather, to quote an instance from Scripture: Barzillai of Gilead, when he declined in favour of his youthful son the kindnesses of King David and all the charms of his court, taught us that old age ought neither to desire these things, nor to accept them when offered.
4. As to your calling God to witness that you had not written a book against me, and of course had not sent to Rome what you had never written, adding that, if perchance some things were found in your works in which a different opinion from mine was advanced, no wrong had thereby been done to me, because you had, without any intention of offending me, written only what you believed to be right; I beg you to hear me with patience. You never wrote a book against me: how then has there been brought to me a copy, written by another hand, of a treatise containing a rebuke administered to me by you? How comes Italy to possess a treatise of yours which you did not write? Nay, how can you reasonably ask me to reply to that which you solemnly assure me was never written by you? Nor am I so foolish as to think that I am insulted by you, if in anything your opinion differs from mine. But if, challenging me as it were to single combat, you take exception to my views, and demand a reason for what I have written, and insist upon my correcting what you judge to be an error, and call upon me to recant it in a humble παλινῳδι'α, and speak of your curing me of blindness; in this I maintain that friendship is wounded, and the laws of brotherly union are set at nought. Let not the world see us quarrelling like children, and giving material for angry contention between those who may become our respective supporters or adversaries. I write what I have now written, because I desire to cherish towards you pure and Christian love, and not to hide in my heart anything which does not agree with the utterance of my lips. For it does not become me, who have spent my life from youth until now, sharing the arduous labours of pious brethren in an obscure monastery, to presume to write anything against a bishop of my own communion, especially against one whom I had begun to love before I knew him, who also sought my friendship before I sought his, and whom I rejoiced to see rising as a successor to myself in the careful study of the Scriptures. Wherefore either disown that book, if you are not its author, and give over urging me to reply to that which you never wrote; or if the book is yours, admit it frankly; so that if I write anything in self-defence, the responsibility may lie on you who gave, not on me who am forced to accept, the challenge.
Source: Letters (New Advent)