According to Kant’s ethics, at least on one common interpretation, persons have a special worth or dignity that demands respect. But personhood is not coextensive with human life; for example, individuals can live in severe dementia after losing the capacities constitutive of personhood. Some philosophers, including David Velleman and Dennis Cooley, have suggested that individuals living after the loss of their personhood might offend against the Kantian dignity the individuals once possessed. Cooley has even argued that it is morally required on Kantian grounds for those who realize that they will lose their personhood as a result of dementia (e.g. Alzheimer’s) to hasten their deaths (e.g. commit suicide). This article specifies circumstances in which post-personhood living might indeed involve an affront to the Kantian dignity of a person who once was. However, the article contends, Kant implies that it is neither morally required nor even morally permissible for someone in an early stage of Alzheimer’s to hasten their death to avoid such an affront, even if they have autonomously chosen to do so. The article adds an ethical perspective to debate on physician-assisted dying, in particular on the moral permissibility of the soon-to-be-demented ending their lives.