This “open letter” to Christopher Boorse is a response to his influential naturalist analysis of disease from the perspective of linguistic-analytic value theory. The key linguistic-analytic point against Boorse is that, although defining disease value free, he continue to use the term with clear evaluative connotations. A descriptivist analysis of disease would allow value-free definition consistently with value-laden use: but descriptivism fails when applied to mental disorder because it depends on shared values whereas the values relevant to mental disorders are (...) highly diverse. A part-function analysis, similarly, although initially persuasive for physical disorders, fails with the psychotic mental disorders because these, characteristically, involve disturbances of the rationality of the person as a whole. The difficulties encountered in applying naturalism to mental disorders point, linguistic-analytically, to the possibility that there is, after all, an evaluative element of meaning, deeply hidden but still logically operative, in the concept of disease. (shrink)