1. I had frequently, Demetrianus, treated with contempt your railing and noisy clamour with sacrilegious mouth and impious words against the one and true God, thinking it more modest and better, silently to scorn the ignorance of a mistaken man, than by speaking to provoke the fury of a senseless one. Neither did I do this without the authority of the divine teaching,2    Some add, “and name.” since it is written, “Speak not in the ears of a fool, lest when he hear thee he should despise the wisdom of thy words;”3    Prov. xxiii. 9. and again, “Answer not a fool according to his folly, lest thou also be like unto him.”4    Prov. xxvi. 4. And we are, moreover, bidden to keep what is holy within our own knowledge, and not expose it to be trodden down by swine and dogs, since the Lord speaks, saying, “Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you.”5    Matt. vii. 6. For when you used often to come to me with the desire of contradicting rather than with the wish to learn, and preferred impudently to insist on your own views, which you shouted with noisy words, to patiently listening to mine, it seemed to me foolish to contend with you; since it would be an easier and slighter thing to restrain the angry waves of a turbulent sea with shouts, than to check your madness by arguments.  Assuredly it would be both a vain and ineffectual labour to offer light to a blind man, discourse to a deaf one, or wisdom to a brute; since neither can a brute apprehend, nor can a blind man admit the light, nor can a deaf man hear.

0544B I. OBLATRANTEM te et adversus Deum, qui unus et verus est, ore sacrilego et verbis impiis obstrepentem frequenter, Demetriane, contempseram, verecundius ac melius existimans errantis imperitiam silentio spernere, quam loquendo dementis insaniam provocare. Nec hoc sine magisterii divini auctoritate faciebam, cum scriptum sit: In aures imprudentis noli quicquam dicere, ne, quando audierit, irrideat sensatos sermones tuos (Prov. XXIII, 9). Et iterum: Noli respondere imprudenti ad imprudentiam ejus, ne similis fias illi (Prov. XXVI, 4). Et sanctum quoque jubeamur intra conscientiam nostram tenere, nec inculcandum porcis et canibus exponere, loquente Domino et dicente: 0544C Ne dederitis sanctum canibus, neque miseritis 0545A margaritas vestras ante porcos, ne inculcent eas pedibus , et conversi elidant vos (Matth. VII, 6). Nam, cum ad me saepe, studio magis contradicendi quam voto discendi, venires, et, clamosis vocibus personans, malles tua impudenter ingerere quam nostra patienter audire, ineptum videbatur congredi tecum, quando facilius esset et levius turbulenti maris concitos fluctus clamoribus retundere quam tuam rabiem tractatibus coercere. Certe et labor irritus et nullus effectus, offerre lumen caeco, sermonem surdo, sapientiam bruto; cum nec sentire brutus possit, nec caecus lumen admittere, nec surdus audire.