Traditionally, philosophical writings on personal identity have taken the form of attempts to discover the dominant criterion for deciding when a person at one time is identical with a person at some other time. Among the candidates for the role of dominant criterion have been bodily continuity (or continuity of some appropriate part of the body) and memory (or the ability, in principle, to remember). In the normal case, where a person P is identical with a person P′ at an earlier time, it is true that P and P′ share a continuous body, that P can remember experiences of P′, and that many other relationships (e.g. similarity of character) hold between P and P′. Consequently, the debate as to which of the normal criteria is the dominant one has usually taken the form of imagining strange cases in which one or more of the normal criteria are lacking, and attempting to say, in such cases, who is identical with who. The scene was set, at least for modern times, by Locke's prince/pauper example, in which, according to Locke, the ability to remember experiences of a person having a different body guarantees, nevertheless, that one is that person—and hence that the memory criterion is dominant over the bodily identity one.