  By far the most popular view of personal identity, until quite  recently, has been a significantly amended version of Locke's  relational memory criterion. To make such a view plausible, though,  the three objections just detailed need to be addressed. Start, then, with  Butler's complaint that memory presupposes identity, that I can  remember only my own experiences, so memory just reveals to me my identity relation to some past experiencer and cannot constitute that  relation. Following Sydney Shoemaker (1970) and Derek Parfit (1984),  one can introduce a more inclusive memory relation, called  quasi-memory, or q-memory, defined so that it does not  presuppose identity. I have a q-memory of some past experience  just in case that experience occurred to someone and my  memory of the experience was caused in the right sort of way by the  experience I now remember. Regular memory, then, would just be a  subset of q-memory (applying to ordinary instances when I was the  person to whom the remembered experience occurred), and q-memory  could be the relevant relation incorporated into the theory of  identity in a way that avoids Butler's objection.