 It is worth considering why one might think that the metaphysical issue is not worth pursuing. The obvious reason is if one thought that there was no answer to the question “what makes this individual numerically distinct from that one?”—that nothing makes them distinct, they just are. An advocate of this view might point out that even if we accept that matter is what makes this individual distinct from that one, we still have no answer to the question “what makes this portion of matter numerically distinct from that one?”. There will always be certain of these numerical distinctness facts that remain unexplained on any theory. But if explanation has to stop somewhere, why not stop at the beginning? Why not just say that it is a bare fact that Socrates is numerically distinct from Callias, and leave matter out of it?