Abstract This paper is an examination of Galen Strawson’s theory of the human person as a succession of momentary selves (or SESMETs: Subjects of Experience that are Single MEntal Things). Insofar as there is a clear distinction between enduring objects and events or processes, SESMETs would seem to partake of the features of both, for they are at once short-lived subjects of consciousness and brief episodes of consciousness. Strawson in fact rejects the object/ process distinction, and contends that there is no sense in which a SESMET is a process and a rock is not a process. Strawson’s rejection of the object/process distinction is essential to his attempt to meet the charge that the concept of a SESMET is an incoherent conflation of the concept ‘object’ and the concept ‘process.’ But many philosophers will find the rejection of the object/process distinction objectionable on general metaphysical grounds. I suggest that these philosophers (I am one of them) and Strawson will not be able usefully to discuss issues in the philosophy of mind (such as his theory of SESMETs) till they have reached agreement about what the most fundamental ontological categories are.