Abstract

Decision-making capacity (DMC) is normally taken to include (1) understanding (and appreciation); (2) the ability to deliberate or weigh up; and (3) the ability to express a choice. In an article published recently in PPP, Jacinta Tan and her colleagues (2006) suggest that DMC requires also (4) the absence of 'pathological values' (i.e., values that arise from mental disorder). In this paper, I argue that although (1)–(3) might be necessary for DMC, (4) is not necessary (barring cases where pathological values interfere with (1)–(3)). My argument will simply be that (4) fails to be supported by the empirical data provided by Tan et al., which I claim supports the view that people with pathological values do often have DMC. I also consider but reject the claim that pathological values entail incapacity because they are not 'authentic' to the person. I conclude that the absence of pathological values does not constitute an additional element of DMC and that we cannot justify compulsory treatment of people who have (1)–(3), but not (4), on the grounds they lack DMC.