Identity Williams on Identity

In a series of relatively simple though complexly-worded (out of necessity) thought experiments regarding body-swapping and changes to memory and the mind, Bernard Williams attempts to demonstrate that identity should be identified with the body rather than with the mind when identity is extended into the future (and by extension during the present). Whether or not Williams is successful in this attempt is a matter of much debate, with this author finding some fundamental flaws in the very premise of the comparisons and thus the conclusions, however the argument is fairly elegant and persuasive and certainly worth of closer inspection. A careful reading of the argument might lead one to a conclusion opposite to that which was intended, but is no less rewarding for this unusual quirk.

Williams begins by dispensing with several considerations that are not germane to his argument, and while some could find room to quibble with these dispensations they truly are not of importance to Williams' central argument or its flaws. Getting to the heart of the matter, Williams assumes that there are two people, a and B, have agreed to take part in an experiment wherein a's mind will be transferred into B's body and vice-versa -- a case of body-swapping....

Williams concludes, and it can be agreed, that a will rationally believe that he will occupy B's body -- that his identity will be transferred into the other's body along with his mind -- and that B. will similarly conceive of an identity transfer, as well. a-body-person, identified by the body of the person that was a prior to the experiment, will have B's mind and identity, that is, while B-body-person (the physical body of the person identified as B. prior to the experiment) will contain the mind and identity of a.
This appears a rational conclusion to Williams, and so he proceeds to imagine that prior to the experiment both persons a and B. will be asked to give a preference for one of two outcomes following the experiment: A-body-person can be given $100,000 while B-body-person is tortured, or B-body-person can be given the $100,000 while a-body-person is tortured. As the rational projection of identity in this scenario is for a to assume he will be B-body-person and for B. To assume that he will be a-body-person, each would rationally and selfishly be expected to show a preference for the outcome in which their old body received the torture while their new body -- along with their mind and identity -- received the $100,000. This cements the projection of identity as traveling with the mind; believing that he will occupy B's body and therefore be B-body-person, a will choose for a-body-person to receive…