has written a wonderful book on the nature of the self; it is called `Divided minds and successive selves'. It is part of the MIT Press series on Philosophical Psychology: Disorders in Mind. I learned from the dust cover that Radden has training both in abnormal psychology and in analytic philosophy. This shows in the depth of analysis and sensitivity to the material that Radden displays.
On the face of it, selves come, in Dan Dennett's phrase, `one to a customer'. Each of us is (has?) precisely one self. But there are cases in which this rule is challenged. The cases range from the most everyday, simple ambivalence, to the extremely rare, full-blown dissociative disorders. The question Radden raises is: Which, if any, of these cases warrants description in terms of multiple selves? Let me sharpen this question.
Clinicians, apparently, find it useful to describe various cases of `dissociative personality disorder' as examples of people who have multiple selves and, therefore, violate the one to a customer rule. But a question remains: In so describing, are they being literal or metaphoric? Of course, for the purpose of doing therapy it may not matter much; therapists may not need to care whether they are being literal or metaphoric. But in other contexts and for other purposes it matters vitally.
The self, obviously, is one of those keystone concepts. It holds together lots of disparate and important things. Selves are (somehow) deeply connected to bodiesΓwe resist the idea of a disembodied self. Selves are also connected to responsibility, and, surely, to consciousness. They are also connected to important emotionsΓshame, pride, and so on. So one way to ask the question, then, about whether we seriously (literally) want to believe that there are violations of the `one to a customer' rule is by asking what happens to these other issues if we violate the rule. What happens to our notions of responsibility and consciousness if we allow more than one self to a body?
Radden's answer is (to my surprise) that in the empiricist tradition of conceptualizing the self, the tradition that comes down through Hume and James and Wittgenstein, yes, one can violate the one to a customer rule without doing grave damage to crucial ideas such as the idea that people are responsible for their actions. The reason this conclusion surprises me, is that it seems that what justifies our treatment of people is a certain sort of continuity, and, on the face of it, it seems that allowing serious talk of multiple selves dissolves that continuity. Radden agrees with this, but points out that though a certain measure of continuity is needed to make our treatment of people justified and, indeed, rational, that continuity need not extend as far and wide as one might suppose. In particular, it need not extend a whole lifetime. And a self need not be utterly unitary for it to have enough coherence at a given moment, and to be a fit target for the sorts of ascriptions we want to make.
Of course, if we are to allow talk of multiple selves and not make a hash of our usual ways of talking and thinking about people, we must do so sparingly and carefully. Radden argues for four criteria that must be met for us to be willing to say that there are multiple selves.
The criteria include that the different selves have different agendas or wills, that they have different traits of personality, that each of the selves persists through time, and, finally, that there be disorders of awareness such that (to a greater degree than is usual for people) one self does not remember what the other one is doing (or has done). Under these very special (and rare) circumstances we can violate the one-to-a-customer rule and not cause the architecture surrounding the self to crumble.
John Austin, the great Don of Oxford philosophy in the 1950s, argued that there were two, at least, sources of insight that philosophers ought to take advantage of: the law, and clinical psychology. Rare indeed is it for anyone to take such good advice; Radden has.