The argument that imagination is not a safe guide to possibility cannot apply in the mind-body case.

A major rationale of those who think that imagination is not a safe indication of possibility, even when such possibility is not eliminable a priori, is that we can imagine that a posteriori necessities might be false – for example, that Hesperus might not be identical to Phosphorus. But if Kripke is correct, that is not a real possibility. Another way of putting this point is that there are many epistemic possibilities which are imaginable because they are epistemic possibilities, but which are