So I was walking home and then it hit me -- Stump and myself are probably interpreting Aquinas in more or less the same way. The culprit is not Aquinas interpretation but the interpretation of PAP. I think this would explain a lot.
As I said, the argument goes by fairly quickly, so there are parts that are slightly obscure. But Stump emphasizes the fact that necessity of natural inclination is like necessity of end. An example of necessity of end: if I want to cross the ocean, I need a transport capable of crossing it.
Now, I think the difference between Stump and myself might turn out to be whether this sort of necessity violates the formulation of (PAP) below -- she thinks it does, I think it doesn't.
This is why I love philosophy: there's always more than meets the eye. And it's also why, of all the modes of doing philosophy, I love history of philosophy best, because I meet this all the time there: refutations can turn out to be exactly right, and yet not refute; supporting arguments can turn out to be flawless, and yet not support; two opposing sides can turn out to agree on precisely the sort of thing thought to be at issue, and disagree on what was thought to be shared. Turning the crystal the right way lets the light through. It's just rare that I get the chance to do it with myself!
