3 We all know what he wrote to you, what charge he brought against you, wherein (as you maintain) he has slandered you. Answer the points, one by one; follow the footsteps of this letter; leave not a single jot or tittle of the slander unnoticed. For if you are careless, and accidentally pass over any thing as I believe you on your oath to have done, he will immediately cry out: “Now, now, you have got the worst of it, the whole thing turns upon this.” Words do not sound the same in the ears of friends and enemies.
An enemy looks for a knot even in a bulrush; a friend judges even crooked to be straight. It is a saying of secular writers that lovers are blind in their judgments, though, perhaps, you are too busy with the sacred books to pay any attention to such literature. You should never boast of what your friends think of you. That is true testimony which comes from the lips of foes. On the contrary, if a friend speaks in your behalf he will be considered not as a witness but a judge or a partisan.
This is the sort of thing your enemies will say, who perhaps give no credit to you, and only wish to vex you. But I, whom you say you have never willingly injured, yet whose name you are always bound to bandy about in your letters, advise you either to openly proclaim the faith of the Church, or to speak as you believe. For that cautious mincing and weighing of words may, no doubt, deceive the unlearned; but a careful hearer and reader will quickly detect the snare, and will show in open daylight the subterranean mines by which truth is overthrown.
The Arians (no one knows more about them than you) for a long time pretended that they condemned the Homoousion on account of the offense it gave, and they besmeared poisonous error with honeyed words. But at last the snake uncoiled itself, and its deadly head, which lay concealed under all its folds, was pierced by the sword of the Spirit. The Church, as you know, welcomes penitents, and is so overwhelmed by the multitude of sinners that it is forced, in the interests of the misguided flocks, to be lenient to the wounds of the shepherds. Ancient and modern heresy observes the same rule— the people hear one thing, the priests preach another.
Source: To Pammachius Against John of Jerusalem (New Advent)