Parfit claims that use of the language of personal identity implies that psychological continuity provides a criterion of identity. The criterion might be described as A and B are the same if they are psychologically continuous and no person is psychologically continuous with the other. Williams argued this view by pointing out that identity is a one to one relation so its criterion must be logically one to one as well, but psychological continuity is not logically one to one therefore it cannot provide a criterion. Because we use of the language of personal identity to imply psychological continuity, it is one to one. If psychological continuity took branching form then we would have to abandon the language of identity. Overall Parfit claiming is even if psychological continuity isn’t always one to one or provide a criterion of identity, the relation of non-branching psychological continuity is logically one to one.…show more content… If every question of identity have an answer, then there is an answer in the double transplant case (p1). If there is an answer in double transplant case, then the original person does not survive, survives as one of the resulting two people, or survives as both (p2). It is not the case that the original person does not survive, survives as one of the resulting two people, or survives as both (p3). Justification for P3 is that the original person survives because people have survived after losing half of the brain through successful transplant. The original person does not survive as one of the two people because there is no way to determine who’s who. The original person does not survive as two people because it violates one to one relation and those two people would be different. In conclusion, not every question of identity have answer (c1). [Reference: class
