Mental Illness and Reductionism: Can Functions be Naturalized?

There has been considerable recent philosophical work on the nature of mental illness. Two opposed themes have been whether the diagnosis of mental illness is necessarily evaluative and whether it can be construed as a failure of function. Concentrating on function, I aim to place some of the key contributions to the recent debate in the context of reductionist forms of naturalism.

Recent debate is best understood as a consideration of whether function can be given a naturalistic reduction. The "value theorists" are correct that it cannot. However, the reduction fails not because functions necessarily presuppose values, but because it relies on a pattern of explanation foreign to the austere description of the reducing language.

I make two further suggestions. First, reducing functions to descriptive austere language cannot help in defining illness. Second, naturalism need not be reductionist. Thus, the failure of the reduction does not show that values are any the less part of the natural world.