Hi Neil:

Well, I wonder how many people still really do think of math as a branch of logic. I would say that that's not right; you need Zermelo-Frankel set theory with the Axiom of Choice. Or maybe we could say that we need some restricted set of 2nd order axioms of the kind Simpson has investigated.

Even with these assumptions, I would probably not say that mathematics is subsumed under set theory. Yes, you can derive mathematics from ZFC, but that reduction does not make math part of ZFC, is what I mean. Maybe you and I are in agreement on that point, just thinking about your remark that there is geometry and then after that you can make up a axiom system for that geometry.

Enderton told me, when I was his TA for set theory at UCLA, that most mathematicians were Platonists. I was absolutely stunned. My first thought was, what am I doing here? He may be right. I know that it's a common, uh... affliction, amongst analysts and set theorists and foundational people in general. But, I find that the algebraists and geometers are more inclined to some variant of formalism. Or at least anti-Platonism. Thanks! --Ron