While I was dusting off books to return them to a shelf, a copy of Dante's De Volgari Eloquentia happened to open to Book II, Chapter 1, where I noticed
And since language is an instrument for our thoughts just as a horse is for a soldier, and since the best horse is appropriate for the best soldier, so the best language suits the best thoughts. But the best thoughts are impossible without learning and intelligence; so the best language will suit only those who have intelligence and learning.
Unfortunately, he goes on to say, not all poets are equipped with intelligence and learning.