In ‘Rethinking Disease’, Powell and Scarffe1 propose what in effect is a modification of Jerome Wakefield’s2 3 harmful dysfunction analysis (HDA) of medical (including mental) disorder. The HDA maintains that ‘disorder’ (or ‘disease’ in Powell and Scarffe’s terminology) is a hybrid factual and value concept requiring that a biological dysfunction, understood as a failure of some feature to perform a naturally selected function, causes harm to the individual as evaluated by social values. Powell and Scarffe accept both the HDA’s evolutionary biological function component and its incorporation of a value component. Their proposed ‘new twist’ is to revise the value component: ‘Our proposed definition of disease is as follows: a biomedical state is a disease only if it implicates a biological dysfunction that is, or would be, properly disvalued’. So, they propose that a disorder is a ‘properly disvalued dysfunction’ rather than a ‘harmful dysfunction’, an…