Paternalism has attracted new defenders in recent years. Such defenders typically either downplay the normative significance of autonomy or deny that we are sufficiently rational for paternalistic interventions to be objectionable.1 Both of these argumentative strategies constitute challenges to John Stuart Mill’s influential anti-paternalistic ‘harm principle’, which states that coercive interference with the liberty of competent adults is justifiable only if such interference prevents harm to non-consenting third parties (Mill, p. 23).2 In this journal, Wilkinson has provided a novel, provocative defence of paternalism in the medical context—one that (provisionally) accepts rather than challenges Mill’s harm principle.3

Wilkinson’s argument is complex. But he begins with Parfit’s influential account of personal identity.4 According to Parfit, Alice at T1 can be the same person as Alice at T2, but the extent to which Alice at T1 and Alice at T2 are similar depends on the extent to which there are ‘chains’ of strong psychological connections between Alice at T1 and Alice at T2. Strong psychological connections, in turn, are mental states such as intentions or beliefs, or psychological traits. For example, if Alice at T2 remembers very little about herself the day before, and the day before that, all the way to Alice at T1, Alice at T2 has completely different psychological traits than Alice at T1—for example, Alice at T1 was courageous, whereas Alice at T2 is cowardly—then Alice at T1 and Alice at T2 are distinct persons.

If the harm principle is correct and Alice is autonomous, it is permissible to interfere with Alice’s liberty only if it prevents harm to some non-consenting third party. But if we accept Parfit’s view on personal identity, then a novel defence of paternalistic intervention emerges: Alice at T2 may well be a distinct person from Alice at T1. So, …