 However, it will sometimes be difficult to tell which claims in philosophical ethics require empirical substantiation. Partly, this is because it is sometimes unclear whether, and to what extent, a contention counts as empirically assessable. Consider questions regarding “normal functioning” in mental health care: are the answers to these questions statistical, or evaluative (Boorse 1975; Fulford 1989; Murphy 2006)? For example, is “normal” mental health simply the psychological condition of most people, or is it good mental health? If the former, the issue is, at least in principle, empirically decidable. If the latter, the issues must be decided, if they can be decided, by arguments about value.