A number of prominent writers on the concept of mental illness/disease are committed to accounts which involve rejecting certain plausible widely held beliefs, namely: that it is part of the meaning of illness that it is bad for its possessor, so the concept of illness is essentially evaluative; that if a person has a mental illness, that is a fact about him; and that the same concept of illness is applicable in the case of mental illness as in that of (...) physical illness. Methodologically this is unattractive. We should seek accounts of concepts which preserve our pre-theoretical beliefs so far as is possible. In this paper I argue that these writers are driven to this pass because they accept certain underlying metaphysical commitments including, in particular, the fact-value distinction. I then claim that there is an alternative account of mental illness (defended more fully elsewhere) which preserves our pre-theoretical beliefs, and that this account can be further buttressed because it coheres with a metaphysical picture which does not involve the metaphysical assumptions which led to the unattractive results noted above. The metaphysical picture and the account of mental illness are thus mutually supportive and suggest that there is good reason to reject the supposed fact-value distinction. (shrink)