Is Multiple Realizability Compatible With Antireductionism?

Jaegwon Kim attempts to pose a dilemma for anyone who would deny mind/body reductionism, namely that one must either advocate the wholesale reduction of psychology to physical science or the sundering of psychology into distinct fields each one of which is reducible to physical science. Supposedly, the denial of mind/body reduction is not an option. My aim is to show that this is not a genuine dilemma, and that antireductionism is an option, if one recognizes that natural-kind individuation is not wholly a matter of metaphysics but is, at least to some degree, a matter of convention as well. The central point is that physical sciences and mental sciences have somewhat different criteria for individuating kinds.