Introduction It seems conceivable for an individual to go through “fission”. Maybe half of an individual’s brain can be kept alive and put in one body, and the other half of an individual’s brain kept alive and put in another body. Parfit envisions this happening to him, and wonders critically about what will happen to him. He proposes three possibilities: he does not survive; he survives as one of the two individuals; and he survives as both “in that he has two bodies and a mind that is divided” (Loux 375). Parfit thinks that each of these three possibilities should be rejected. Moreover, he wants to refute that for any question concerning personal identity in any case, there must be an answer that is true (Loux 375). He argues that if all the possible answers are unbelievable, then it is difficult to decide which of them is true, and difficult to even keep the belief that one of the answers must be true (Loux 375). He continues saying that if individuals do away with this belief, as he thinks it should be, then these problems will disappear (Loux 375). Parfit’s main use of fission argument is to inspire the claim that identity of an individual does not matter in survival.
Arguments
Parfit’s fission argument emphasizes the hardship of deciding whether a thought experiment is acceptable or not. The argument assumes the possibility of brain bisection or commissurotomy, that is, the puncturing of the corpus callosum, that is, the removal of the cerebral cortex surgically of