Hmmm.
So Latin’s meaning changes over the course of time, and even within the works of one philosopher? This makes it sort of hard to understand, no?
If he was just having a conversation there wouldn’t be such a problem. But when people write theology or philosophy they tend to employ terms in rather specific ways. It would seem that the best way to see what an author means by a term would be first and foremost 1. in the work which you are examining and 2. in the rest of his corpus.
That would be prudent to do with any writer.
As for Latin changing meanings-- I think this happens universally. In Greek as well, terms started vaguely and as Church theology was hammered out in successive ages and with councils the terminology came to mean what it means today. Hence someone like Cyril talking of the, ‘one phusis of the Incarnate Word.’
But for Latin in particular I think it is very helpful not to anachronistically project aristotelian terminology onto Church Fathers, because they were not aristotelians.
I think these are all fair considerations. None of them, I think, make ascertaining Pope St. Gelasius’s meaning hard to understand. The only thing that is particularly hard would be reading him widely-- and I think only a scholar would have to do that if he wished to find ‘the meaning’ of terms as used by Gelasius. For most of us, we read the word in context and from that discern what it means.
What I’m advocating most of all is reading the term in context and
not in an aristotelian way (which is completely out of context). And that could be done simply by reading the work in question, which seems fair enough if we’re trying to find out what the author means.
-Rob