Nullius unquam

Hello,

I’m trying to understand a construction that’s cropped up in a medieval text I’m working through. The author (Richard of St. Victor) poses the following question:

an inde dicatur summa natura, quod nullius unquam possit major esse quam illa, an ita veraciter est summa, ut sit usquequaque sit perfecta?

(the “highest nature” he’s discussing is the Divine Nature, though that’s not relevant to the syntax necessarily).

To my eyes, the sentence reads straightforwardly enough, except for the phrase nullius unquam. A search at Perseus revealed that this combination pops up in Cicero a few times, meaning it’s not a medieval oddity. I think the basic meaning is “nothing ever,” but I’m trying to figure out the logic of the construction. In particular, why is nullius in the genitive?

I appreciate any insights that the community can offer! Thanks!

“the highest nature, because the nature of nothing/no one can ever be greater than that [nature]”

That makes sense, thanks!