Abstract
When making decisions on behalf of someone, is asking what they would have wanted a good way to respect their autonomy? Against prevalent assumptions, I argue that in decisions about the care and treatment of those with advanced dementia, the notion of ‘what one would have wanted’ is conceptually, epistemically, and practically problematic. The problem stems from the disparity between the first-person subjectivity of the past person and that of the present person. The transformative nature of dementia renders the very meaning of ‘what the patient would have wanted’ problematic. When applied to those with advanced dementia, the subjunctive notion is either (i) incoherent, (ii) fundamentally indeterminate, or (iii) normatively irrelevant.