The biographical dilemma: an arrow-style impossibility theorem concerning the problem of the true self

Ever since ancient times, “Know yourself” has been widely accepted as one of the first commandments of wisdom. It is not at all obvious, however, how one is supposed to go about answering the question “Who am I?” Psychology attests people tend to recognize their values as the core of who they are [20]. Although this may well be the case, it is a simple fact of experience that people’s values may change throughout their lives. If so, then knowing oneself would be mostly a matter of specifying which values are (in some sense) truly one’s own. Of course, the specification of such values should be somehow responsive to the values a person actually upholds throughout life, if they are to be indeed a person’s own. Following the Arrovian tradition of social choice theory [1], we take values to be preferences over states of affairs, and thus the question of the true self so formulated to be a problem of preferences aggregation. By means of this formal approach it is shown that, given some fairly mild and intuitively plausible conditions a procedure for answering the question of one’s true values should satisfy, there is no universally applicable procedure for obtaining that answer. Put simply, we are led to the conclusion that there may be people for whom the question “Who am I?” has no answer at all. Alternatively, this result may be interpreted as entailing that some people cannot be reasonably taken to maintain a single true self throughout life. In the light of this interpretation, some of the wider consequences of the result to the problems of personal identity are then briefly considered.