Legal scholarly analysis of criminal responsibility is typically assumed to encompass non-responsibility. This reflects the influence of the legal-philosophical tradition on the study of criminal responsibility, in which responsibility and non-responsibility are alternative outcomes of the same moral-evaluative enquiry of calling individuals to account for their criminal conduct. This article questions that operative assumption. A close examination of four dimensions of responsibility and non-responsibility – the bases for ascription of criminal responsibility and non-responsibility, attendant rules of evidence and procedure, the temporal logics of responsibility and non-responsibility, and what I call the effects of ascribing responsibilit...