but there are many kinds of differences in the world and only some of these are cultural. and here i bring in a second component of my proposal about the adjectival form of the word culture. i suggest that we regard as cultural only those differences that either express, or set the groundwork for, the mobilization of group identities. this qualification provides a brute principle of selection that focuses us on a variety of differences having to do with group identity, both within and outside any particular social group. in putting the mobilization of group identities at the heart of the adjective cultural, i have in fact made a move that looks, at first glance, retrogressive, as it appears that i am beginning to bring the word culture uncomfortably close to the idea of ethnicity. and that gets me into some new problems that need to be unraveled.