Laudator Temporis Acti

Georg Christoph Lichtenberg (1742-1799), Philosophical Writings, tr. Steven Tester (Albany: SUNY Press, 2012), p. 48 (Sudelbücher, C 151):

The rules of grammar are merely human dictates, which is why the devil himself speaks poor Latin through the possessed.

Die Regeln der Grammatik sind bloße Menschen-Satzungen daher auch der Teufel selbst, wenn er aus besessenen Leuten geredet, schlecht Latein geredet.

On the other hand, "schlecht Latein" is not incompatible with piety, according to St. Gregory the Great, Moralia in Job (Patrologia Latina 75.516 B, tr. E.K. Rand):

Wherefore I have scorned to observe all art of style, in which pupils are drilled in schools of the outer [i.e., lower] training. For, as the tenor of the present letter makes evident, I shun not the collision of m's; I avoid not the disorder of barbarisms; I despise a conformity to constructions and moods and cases of prepositions. For I deem it exceedingly inept to fetter the words of the Heavenly Oracle to the rules of Donatus.

Unde et ipsam loquendi artem, quam magisteria disciplinae exterioris insinuant, servare despexi. Nam sicut hujus quoque epistolae tenor enuntiat, non metacismi collisionem fugio, non barbarismi confusionem devito, situs motusque et praepositionum casus servare contemno, quia indignum vehementer existimo, ut verba coelestis oraculi restringam sub regulis Donati.

Hat tip: Ian Jackson.