> What it usually means and what it means here are two different chickens my guy.

Sorry, what? The meaning of language is in use. If you use a word in a way that nobody would use it wouldn't mean anything. Here, the use of the word quality is pushing it; it borders on being incorrect.

What would it mean to say: Quality is not an act? Does it mean something like: a characteristic of something is not an act? Or does it mean: virtue is not an act? If the latter (and the latter is correct), then do you see why the word quality is used wrongly?

Of course, it is possible to read quality as an abstract noun. The point is this: the abstract noun "quality" doesn't mean what it means here. It usually means "characteristic" or "attribute", not "virtue", "excellence", etc.

That's a different use of the word quality than in the quote! Here quality is used as an adjective as in: quality work, quality time, a quality product, etc. As opposed to: what qualities do you have, since in the latter case quality is a neutral term (and in the quote it's clearly positive).

In Greek adjectives can be used substantively, i.e. as a noun. Though in this case, I'm fairly certain the original word aretē is just a noun, meaning "virtue" or "excellence."

That sounds more like Aristotle!

Quality is such a weird translation of (I assume) ἀρετή; the usual translation is virtue. The context of this quote is that Aristotle is giving an account of how one can develop the correct appetites or desires (separate from rationality). This is because he thinks that the truly virtuous man is in harmony with himself: he both desires and knows what the right thing to do is.