The United Nations Convention on the Rights of Persons with Disabilities (CRPD) is being used to argue for wider recognition of the legal capacity of people with mental disabilities. This raises a question about the implications of the Convention for attributions of criminal responsibility. The present paper works towards an answer by analysing the relationship between legal capacity in relation to personal decisions and criminal acts. Its central argument is that because moral and political considerations play an essential role in (...) setting the relevant standards, legal capacity in the context of personal decisions and criminal acts should not be thought of as two sides of the same coin. The implications of particular moral or political norms are likely to be different in these two legal contexts, and this may justify asymmetries in the relevant standards for legal capacity. However, the analysis highlights a fundamental question about how much weight moral or political considerations should be given in setting these standards, and this is used to frame a challenge to those calling for significantly wider recognition of the legal capacity of people with mental disabilities on the basis of the Convention. (shrink)