Note: here I am not trying to explicate the philosophical positions that Proust himself may have had, rather I am using In Search Of Lost Time as a jumping off point from which to investigate various philosophical issues. Obviously then what I have written here is just one part of an ongoing project.
There are three natural candidates to identify the person with: the process of consciousness, the inner personality (a.k.a various properties of that conscious process), and external personality. Of these three we can immediately rule out the process of consciousness as a candidate for being the person. Consciousness may be interrupted, for example, it is reasonable to suppose that at night there are times in which we are not conscious, or when we suffer a blow to the head, or if we are frozen only to be thawed at a later date. If it is interrupted obviously the conscious process before and after the interruption aren’t the same process, although one might be seen as the natural continuation of the other. Thus to adopt it as the person would be to accept that people are constantly dying only to be replaced by imposters, over and over again, and that you yourself have only really existed for perhaps a day, and that the memories you have of existing previously are really the memories of somebody else. Clearly then the conscious process is not what we meant to talk about when we talk about the person.
The inner personality is a much better choice. The inner personality is the way in which a particular conscious process works (how it thinks, feels, its dispositions, memories). Numerous conscious processes could in theory have the same inner personality; even though the same conscious process isn’t present when I go to sleep and wake up the same inner personality is. (Of course there are complications dealing with how the inner personality changes and when the inner personality of one conscious process can be considered the same as, or the natural successor of, that which was present in another. But we will leave these considerations aside for now.) The inner personality is, I think, how we define the person that we think of as ourselves. Drastic changes in our inner personality make us feel like we have become different people. And because of the consistency (as far as we know) between going to sleep and waking up we feel that we are the same person as the one who existed yesterday. So it makes sense to identify the person with the inner personality some of the time. However it doesn’t quite capture what we intend to refer to by talk of the person in most cases. Certainly we don’t have access to the inner personality of anyone but ourselves, except in a very indirect and unreliable way. Thus when we talk of this person or that person we must mean something slightly different.
This brings us to the external personality. The external personality is how a person interacts with others. When talking about the person in the context of thinking of other people it seems natural to define them in terms of our relations to them. How else could we define who they are? (see also) In his book Proust calls this the social personality. He says “… our social personality is a creation of the thoughts of other people. Even the simple act which we describe as ‘seeing someone we know’ is to some extent an intellectual process. We pack the physical outline of the person we see with all the notions we have already formed about him, and in the total picture of him which we compose our minds those notions have certainly the principle place.” But, if we define the person in this way, a given body may house more than one person, because if people run in different social circles they may interact with people in one circle differently than they do in another. In Proust’s book Mr. Swann is an example of this. With Proust’s family Swann is one person, but there is also a second Swann, who lives in the highest social circles. And in fact learning about the other Swann is like meeting a second person, according to Proust. Now of course there is a sense in which me might say that these two Swanns are in fact “the same person”. Such a claim, I think, mixes the two definitions of the person. Specifically it is invoking the idea that there is only one inner personality between the two, because we know that except in the most abnormal cases there is only one inner personality per body. It is not that the claim is wrong, but rather that it brings the two ideas together while using only one word, perhaps confusingly.
Distinguishing the two definitions of the person can be philosophically useful. When thinking about psychological continuity, survival conditions, what things look like to a given person, and so on, the first definition of the person, as the inner personality, is the most useful, since in these areas we feel that the first person perspective has some authority. However, when it comes to social and ethical matters I think we are best served by the second definition, first of all because that is the only kind of person we have access to when deciding these matters. And, more practically, it allows us to leave the philosophy of mind aside and to worry only about how that person acts without delving into any sticky issues regarding their inner state.