Abstract
According to modal empiricism, our justification for believing possibility and necessity claims is a posteriori. That is, experience does not merely play an enabling role in modal justification; it isn’t simply that experience explains how, say, we acquire the relevant concepts. Rather, the view is that modal claims answer to the tribunal of experience in roughly the way that claims about quarks and quails answer to it. One serious objection to modal empiricism is the problem of empirical conservativeness: it doesn’t seem that experience can distinguish between modal claims. And if experience can’t manage that, it’s hard to see how it can provide evidence for one claim over the other. So if modal empiricism is true, we ought to be modal skeptics. On the assumption that we shouldn’t be modal skeptics, we should reject modal empiricism. I have two aims here: first, to reply to this objection to modal empiricism; second, to sketch a modal epistemology that fits with the reply I offer.