Abstract
Psychological individualism is motivated by two taxonomic principles: (i) that psychological states are individuated by their causal powers, and (ii) that causal powers supervene upon intrinsic physiological state. I distinguish two interpretations of individualism--the 'orthodox' and the 'alternative'--each of which is consistent with these motivating principles. I argue that the alternative interpretation is legitimately individualistic on the grounds that it accurately reflects the actual taxonomic practices of bona fide individualistic sciences. The classification of homeobox genes in developmental genetics provides an illustration. When applied to the taxonomy of psychological kinds, alternative individualism has some surprising consequences. In particular, externalist taxonomies of thought are consistent with the alternative interpretation, and hence consistent with individualism. I conclude, on this basis, that the individualism/externalism dispute which has long preoccupied philosophy of psychology is an empty one