Personal identity is an issue or problem which philosophers found increasingly difficult to cope with in the course of the 17th and 18th centuries. Descartes found the notion so unproblematic he hardly mentions it. Locke devotes an influential chapte r to it in the Essay Concerning Human Understanding. Hume found the notion utterly problematic. Issues are a little difficult to formulate here. Still, one might try.
(a) Can Locke's theory of identity be salvaged from the serious objections which have been raised to it? See John Perry ed.Personal Identity for a collection of the most important materials regarding this question.
(b) Is it possible to resolve Hume's problems regarding personal identity within the framework of a Humean system? Another good collection of materials is A.O. Rorty TheIdentities of Persons.
(c) Leibniz was strongly influenced by Locke's theory of personal identity. What features of Locke's account does he reject? Why? Does he have good reasons?