Btw, Wallace’s book on infinity, Everything and More, is an excellent, lucid treatment of the problems within mathematics (which implies scientific theory in general) and its application to the real world.
There are limits at the boundaries not only of mathematics, but also in logics — not only modal logics but even simple first order logic. Reminds me of a Kantian remark Russell made somewhere to the effect that our descriptions of phenomena only approach the phenomena from our descriptive perspective. The things themselves remain utterly mysterious. Worse, our descriptive apparatus is limited. Even ourselves as phenomena (pace Schopenhauer) cannot gain access to ourselves beyond our own descriptive apparatus — language, sensibility, logic and science. We can, at best, observe behavior and derive a few conclusions. Schopenhauer, prior to Darwin and armed only with Eastern religion, mistook that behavior for the thing in itself, when, really, it was just a character of evolutionary survival, not of the entire cosmos of phenomena or noumena. With sufficient scientific research, we approach explanation of both sentient and non sentient behavior … but substance itself? What can you say about the limits of knowledge? Is there a something beyond it or not? I’ve never been impressed with Wittgenstein’s cavalier gnome “It’s not a something, but it’s not a nothing either.” Well, so what? I think Rumsfeld said it better. We can have no access to it, and we don’t even know if there’s a there there.
Which brings me back to the notion of explanation in the sciences: the theory of evolution has explanatory value for psychology (despite Fodor’s just complaint that it is, at this point, merely post hoc and not predictive) because it is a theory independent of emotions or sensibility. It is not just a statistical account of emotions under conditions (the behaviorist model). It is a theory of species development in general. I think Fodor is right that it is post hoc and unpredictive, but it still has explanatory power, just post hoc. Maybe that’s the best place to rest on Fodor’s complaint: natural selection is explanatory but not yet predictive.