A Study On Various Replies To The Reduplication Argument

This paper is focused on the Reduplication Argument concerning the problem of personal identity. As for the Problem of"Who am I after fission?", this paper provides an overview of various replies to it by summarizing several views put forward by some theorists, and clarifying some theses, criteria and descriptions of fact related to the argument in question. We will find that there are two principles in the argument which are in conflict: the numerical principle and the"only X and Y"principle. However we answer the question of"Who am I after fission?", we will either violate one of the two principles, or violate one of the key theses, or violate our intuitions about personal identity, and thus distort the conception of person.Parfit wants to diminish the importance of personal identity. I will explain that Parfit made several mistakes in his thought experiment. In particular, he has largely ignored the complexity of human brain. I will indicate the mistakes in his thought experiment regarding the gradual removal and instertion of parts. In order to prove this, this paper reconsiders Locke's discussion of personal identity, and accepts his opinion to the effect that different ideas correspond to different identityies, Later, I differentiate these ideas at three different levels, and suggest that Parfit didn't understand that personal identity only consists in the ideas of the third level.Regarding the question,'Who am I after fission?', this paper supports the response of'I am both left and right'. The psychological continuity criterion needn't exclude the branch-line case. And I need not transgress either the Numerical Principle or Only X and Y Principle. This response also accord with our intuitions about personal identity that it should be the best response.