This is just too hilarious. It needs no introduction. It’s just great.
Pompeius Grammaticus, the 5th/6th century North African grammarian:
Don’t let anyone tell you, “If we sometimes use an adverb as a noun, we are also obliged to decline the adverb itself.”
For when a nomen is put in the place of an adverb, it maintins its cases; but when an adverb passes into the place of a nomen, there’s no way it can take on a case.
Don’t say to me, “hoc mane: now, if hoc mane is a noun, you ought to decline huius manis, huic mani.”
We don’t find that sort of explanation [ratio ista]; it can’t follow that it’s declined.
“Nonetheless, we read that very declension, a primo mani, in Plautus. [i.e., in the Mostellaria or The Haunted House]. Where di a mani come from, if there isn’t the declension mane, manis, mani?”
mane, from which a primo mani came, produced the declension. But we still shouldn’t decline it.
Why? You want to know why? Because an adverb absolutely cannot be declined!
When we say torvum clamat, torvum is now an adverb, and torvum stands for torve. I’m not allowed, am I, to say, for example, torvi clamat, torvo clamat, a torvo clamat? I’m not, but I pick up that one case for the special use [ad usurpationem]. If, therefore, I pick up that one case when I produce the adverb, and I can’t pick up the other cases, so too when I use an adverb in place of a noun, I’m not allowed to decline it, but have to put the adverb itself in place of the noun. (136.18–35)
But just so you don’t think Pompeius is a total bear, enjoy the following as well:
His note on the word totus:
What’s this that I’ve said? Pay attention. Take, for example, ‘The whole man [totus] was eaten up by a bear’: look now, what does it mean? The whole man all at once, so that nothing was left. ‘The whole man was eaten up,’ that is, his hands, feet, back, everything. (204.11–14)
And last but not least, on rosa:
bene olebant in hospitio meo rosae
The roses in my guest house used to smell good. (102.8)
[Translations, except for the last one, by Robert Kaster in Guardians of Language.]