I think I’ve managed to reason out a solution to my own question - but I’m posting here in a search for confirmation - just in case.
After working very hard to ensure that I truly understand my first two chapters of Wheelock, I dove into the first of 38 Latin Stories. While understanding the tale was simple - I wanted to be sure that I was really grasping why the words meant what they did - so I went through sentence by sentence identifying cases etc.
I got as far as “Prometheus est vir magnae sapientiae;”.
If “Epimetheus est vir sine sapientia” = “… a man without wisdom” then why wasn’t “Prometheus est vir magna sapientia;” or “… a man with great wisdom”?
If common sense eliminates plural Nomative and the singular Dative - that leaves me with Genitive. So, after all of that, here comes my question: (Ready?)
Can I understand my trouble sentence to mean that “Prometheus is a man of great wisdom”? I’ve drilled Genitive = possession into my head - but it looks like I’ve already come across a situation where that’s limiting true understanding. After all, in English we don’t really think that a man of great wisdom is possessed by the wisdom as much as we think that the wisdom is possessed by the man.
It’s good that you are able to recognize the grammatical concept of possession and not just assume that “of” will always correspond to a genitive in Latin. However, in this case it is just the same thing as if we were to say “He is a man of great wisdom”. This is a genitive describing characteristic, not the usual possessive meaning. You can also have an ablative of characteristic as you suggested with “vir magna sapientia”, but this is more common with physical characteristics than intrinsic qualities.
Hmmmm… I just thought of something… not sure if it would be legal, but in my mind it creates an interesting image:
Prometheus est vir magna sapientia.
Assuming this is legal, could it mean something along the lines of “Prometheus is a man through great intellect.”… i.e. in the sense that he is man thanks only to the means provided by some great intellect?? Kinda like man creating God after his own likeness… Or with the subtle (or not so subtle) implication that Prometheus is but a creation of the imagination…