A Dilemma for Personal Identity

Some theories of personal identity allow persons to lose their identities in processes of qualitative change, i.e., to become a numerically different person by getting new physical and/or psychological properties. I shall call these theories strong. Weak theories, in contrast, do not allow for such a loss of identity. In general, weak theories put less restrictions on personal identity than strong ones. I will argue that each type of theory faces a serious problem. Let me start with the strong theory which is built upon the notion of psychological connectedness. Suppose A is a person existing at a certain time, and B a person existing at a later time, then A and B are identical iff they are related by a sufficient number of direct psychological connections. According to Noonan (1989, 12-13) the following types of relations figure as direct psychologica