Boswell, Life of Samuel Johnson:
The truth, however, is, that he loved to display his ingenuity in argument; and therefore would sometimes in conversation maintain opinions which he was sensible were wrong, but in supporting which, his reasoning and wit would be most conspicuous. He would begin thus: ‘Why, Sir, as to the good or evil of card-playing—’ ‘Now, (said Garrick,) he is thinking which side he shall take.’ He appeared to have a pleasure in contradiction, especially when any opinion whatever was delivered with an air of confidence; so that there was hardly any topick, if not one of the great truths of Religion and Morality, that he might not have been incited to argue, either for or against.
Flavio Biondo, On the Words of Roman Speech, (I):
There is a great dispute among the learned people of our time, and a contention in which I have often been involved, whether it is the maternal and as it were, among the rude and unlettered mass in our age vulgar idiom, or by the use of grammatical art, which we call Latin, that the Romans were accustomed to employ as their established mode of speaking.
Arguments are not lacking to those who either impugn or defend one side or the other of this debate. If I were to draw them into the fray, it would become apparent on what foundations each side rests, and there will be material for this dispute so tossed before the eyes of all that any fool ignorant of the laws of speaking, or, as the Florentines are in the habit of calling him, a market-stall judge, would not hesitate to bring forth his opinion easily and ex tempore.
Which I would yet maintain must be born by the judgment of the learned and most knowledgeable in Roman things if for no other reason than so that, when you and many others, the ornaments of the age in judgment, seem to dissent in turn, I alone, in a situation where such great men either entertain contradictions or feel uncertainly, would dare to affirm it for sure.
Magna est apud doctos aetatis nostrae homines altercatio, et cui saepenumero interfuerim contentio, maternone et passim apud rudem indoctamque multitudinem aetate nostra vulgato idiomate, an grammaticae artis usu, quod latinum appellamus, instituto loquendi more Romani orare fuerint soliti.
Nec desunt argumenta utramque vel impugnantibus vel defendentibus partem; quae si in medium adduxero, qualibus utrique nitantur fundamentis apparebit; eritque omnium oculis adeo subiecta huiusce disceptationis materies, ut quilibet iurisdicundi ignarus, sive, ut dicere Florentini solent, iudex emporinus, faciliter et ex tempore sententiam ferre non dubitet.
Quam tamen et docti et rerum romanarum callentissimi iudicio vel ea ratione servaverim ferendam, ne, cum tu pluresque alii, omnium iudicio saeculi ornamenta, invicem dissentire videamini, ego unus, in quo tales viri vel contraria sentiant vel addubitent, id ausim affirmare.