A vast range of questions is raised by Strawson's concentrated and ingenious assault on these problems; his criticisms of the 'Cartesian'and 'no-ownership' views, his notion of 'logically adequate grounds'in connexion with the self-ascription and other-ascription of P-predicates, his account of 'I' as a referring expression , and the sense of the term 'primitive', all invite discussion.I shall confine myself to just one question: the initial distinction between two sorts of predicates.