 This recourse to the world may, however, be a little too swift. Cases of (arguably) deeply explanatory natural kinds such as polio or cats contrast dramatically with cases of more superficial kinds like bachelor or fortnight. whose natures are not specified by any explanatory science, but are pretty much exhausted by what would seem to be the meanings of the words. Again, unlike the case of polio and its symptoms, the reason that gender and marriage status are the best way to tell whether someone is a bachelor is, again, that that’s just what “bachelor” means. Indeed, should a doctor propose revising the test for polio in the light of better theory—perhaps reversing the dependency of certain tests—this would not even begin to appear to involve a change in the meaning of the term. Should, however, a feminist propose, in the light of better politics, revising the use of “bachelor” to include women, this obviously would. If the appearance of the analytic is to be explained away, it needs to account for such differences in our understanding of different sorts of revisions in our beliefs, which don’t appear to be issues regarding the external world.