A Plurality of Selves
- Human beings are persons or selves and they have a specific nature: they have a certain type of psychology and a certain type of biological make-up. Not all possible sentient beings share this nature. For instance, humans have personal memories, consciousness, self-reflection, rationality, and a brain with two hemispheres that is in principle detachable from the body. Arguments about personal identity take these facts for granted and contrive various thought experiments on their basis: transferred brains, divided brains, memory loss, memory upload, personality alteration, and so on. Thus we arrive at theories of personal identity for humans. One well-known argument proceeds from the possibility of brain splits to conclude that personal survival does not logically require personal identity.  But what about other possible types of being that don’t share our human nature? Can’t they be persons or selves too? If so, we can’t expect to derive general “criteria of personal identity” just by considering the human case: we need to look at the full range of possible cases if our theory is to have the generality we seek (and it might turn out not to have that generality).
Consider sentient beings that don’t have brains that can be divided or transferred: the brains of these beings don’t have two equipotential hemispheres and they are distributed throughout the organism’s body (rather like an octopus). There are thus no possible scenarios in which their brain is divided and the hemispheres placed in separate bodies, so there is no way that they can survive without being identical to some future being (at least so far as the standard fission arguments are concerned). We can’t consult our intuitions about what we would say under conditions of brain bisection and relocation, since these are not possible (such surgeries would result in certain death). For these beings there would be no survival under the imagined conditions. In fact, a theory that ties personal identity to the body would be more plausible for them than in the human case: having that brain in that body would be tightly correlated to future survival. There would be no pressure to accept psychological continuity theories if it were not possible to dissociate survival from bodily identity, as in the standard thought experiments. Lesson: be careful not to accept a general theory of personal identity based on the contingent peculiarities of the human organism. That might lead to chauvinism about personal identity, i.e. ruling out bona fide persons as not really so.
Now consider this hypothetical case: sentient beings without personal memories. We can allow that these beings possess general factual memory; what they lack is memory of their past experiences and deeds. Their earlier life is a complete blank to them, though they live and love. They clearly persist through time, but this persistence cannot be a matter of remembering different periods of their existence: they don’t persist through time because of the power of memory. So for these beings personal identity cannot consist in memory links to earlier selves, however it may be for us. We can’t say that A is identical to B because A can experientially remember what B did. These beings may have the anatomy described in the previous case, so their identity is better explained in terms of bodily continuity, not in terms of memory links. Not that bodily continuity will work for everyone: for some possible beings the body changes over time to become a different body, as with bodily metamorphosis (including the brain). Butterfly persons would persist through time while they acquired a brand new body at puberty. So it would be wrong to generalize from the no-memory type of person to all possible types, as it would be wrong to generalize from the human case to all possible cases. The butterfly adults might have vivid memories of their pupa childhood while not sharing their body with that being; in their case a memory criterion might well seem attractive. It all depends on the being.
Here is an even more radical case to consider: the no-consciousness self. It might be claimed that personal identity consists in the persistence of a subject of consciousness over time: and certainly for conscious beings that theory has some appeal (though it doesn’t seem very explanatory). But consider a hypothetical case in which a conscious being loses consciousness during the course of life yet retains an unconscious mind; or a species that was once conscious but now, through natural selection, has abandoned that trait and survives by means of unconscious psychological mechanisms. Such beings might have memories, beliefs, desires, personalities, and so on—they just aren’t conscious. They are, if you like, zombie selves (though with an elaborate unconscious psyche). They would look and sound like conscious persons, living their lives like such persons to outside observation (maybe a bit wooden in certain respects). So they exist through time and possess the usual attributes of persons (except one)—picture them on a remote planet with a functioning civilization. For these beings a theory based on continuity of a conscious subject would be wide of the mark—more like continuity of an unconscious subject.  They have a psychology and they exist through time, but there is no consciousness in there: “unconscious self” is not an oxymoron.
We can thus refute bodily theories, memory theories, and consciousness theories as general theories of personal identity by considering the full range of possible persons.  Maybe there is no general theory available just different theories for different types of being, or maybe some other theory can be contrived; what is clear, however, is that the human case is a special case, not characteristic of all possible cases. Methodologically, then, it is unwise to proceed from this case alone; that will only lead to parochialism and special pleading. We have personal memories, consciousness, and divisible transferable brains, but that is not true of all possible selves, and perhaps not of all actual ones (animals, aliens). The case is unlike theories of persistence for material objects in that the material objects around us are characteristic of material objects in general: if material identity is explicable in terms of spatiotemporal continuity or some such for the objects on earth, then it will be explicable in this way for objects elsewhere, actual and possible. There are no non-spatiotemporal objects to deal with and accommodate. Similarly for set identity: the criterion in terms of identity of membership generalizes to all possible sets—it isn’t limited to the sets we encounter every day. The thing about selves is that they can be “multiply realized” both physically and psychologically, so we don’t want to tie the concept down to a specific type of self—as it might be, adult humans with consciousness, memory, and a divisible anatomy. That would be like defining set identity purely in terms of sets of elephants or ants. The plurality of possible selves imposes a constraint on theories of personal identity, and one that is not easy to meet.
- Let me now turn to a different question involving plural selves, namely whether I could have been a different self: that is, is there a plurality of selves in metaphysically possible worlds that could be said to be possible selves of mine? The question is tricky because I clearly could not have been a different human being: I am necessarily Colin McGinn, given that a certain human being is denoted at both places. Any human being in a possible world that is not identical to this human being is not me. Someone could look and sound like me, but if they are not the same human being they are not me. No member of an animal species can ever be identical to a different member of that species. But it doesn’t follow that I could not have been a different person (associated with the same human being). In fact, this is quite easy to imagine: we just have to suppose that I undergo very different experiences in some possible world. Suppose my experiences in world w involve being born into poverty in a war-stricken land where abuse is rampant and education non-existent: I suffer various life-altering traumas and end up with emotional problems radically unlike those I now have. My personality, my memories, and my abilities are totally different in w: am I not then a different person from what I am today? The person you become is a function of your life experiences, among other things, but these are contingent, so you could have become a different person. You could even be subjected to chemical attacks that rewire your nervous system, or suffer genetic alteration in the womb. It would be the same organism, but it wouldn’t be the same person, because psychology counts in the latter respect. If we call that person you could have become “Albert”, then we can say that you might have been Albert, in the sense that the human being you are could have been associated with (“housed”) another person, namely Albert. You quaperson could not have been identical to Albert, but your organism could have been his residence instead of yours. Thus we derive the paradoxical-seeming proposition, “I could have been a different person”, which translates roughly as, “My organism could have housed a different person”. The word “I” can slip from referring to a human being to referring to the person housed by that human being, but there is a clear sense in which it is true to say, “I might not have been me”: that is, “This human being might have housed someone other than my actual self” expresses a truth. Indeed, I might have been any number of people in this sense, given the plurality of possible lives I (sic) might have led. What my name actually stands for is an interesting semantic question: is it a human being or a person (self)? It seems ambiguous between the two in actual use, which is why I can say, “Colin McGinn might not have been Colin McGinn” without sensing contradiction, where the first occurrence of the name refers to a certain human being and the second refers to the person currently occupying that human being. I am necessarily the person I am, and I am necessarily the human being I am, but that person is not necessarily identical to that human being—in fact, they are not identical at all. In one sense “I am not a (particular) human being” is true, and in another sense “I am not a (particular) person” is true; but it is equally true that I am a human being and also a person! The word “I” is flexible enough to allow for all these statements to be true under the right interpretation.
We can say, then, that across modal space I have many counterpart selves that could each have occupied this particular organism. I have no such human being counterparts—in this respect I am a unity. But I am (associated with) a plurality of selves in the sense that possible worlds contain many such selves corresponding to me. This is not a denial that proper names are rigid designators, since each of these entities has its own name: it isn’t that my counterpart selves are all designated by “Colin McGinn”, construed as a name of a particular person in the actual world. It is quite true that Colin McGinn is necessarily Colin McGinn (under the right interpretation), even though I might have had many numerically distinct counterparts that inhabit my actual body (and were all called “Colin McGinn”). This can be verbally confusing, but the underlying logic and metaphysics are not: one human being, many selves, with names for each of these separate entities. This enables us to say such potentially confusing things as, “Colin McGinn (human being) might not have been (associated with) Colin McGinn (person)”. The name seems capable of referring to both.
- I now take up another issue in which the notion of a plurality of selves suggests itself, namely whether we actually contain more than one self. It is commonly assumed that we contain at most one self, though there have been dissenters to that conservative opinion (as we will see). Hume argued that we contain zero selves, having conducted an internal survey; but most people put the number at unity after no survey at all. It is an interesting question why we do this so readily: has anyone ever actually counted the number of selves he or she contains? Is it that you can tell just by looking that you contain a single self, as you can tell by looking that you have a single body? But you can’t look at yourself and then proceed to count the number of selves in the vicinity. Is it that the ordinary use of “I” suggests unity? But that seems a flimsy way to get at the cardinality. Is it perhaps just a lazy prejudice like assuming there is only one type of person in the world? At any rate, it is apparently a general belief on the part of (human) selves that there is only one of them per organism. If we ask for a demonstration, we are apt to be dismissed as blind to the obvious. Is this just how we appear to ourselves? Maybe, maybe not, but maybe the appearances are misleading: we need a reason to accept that we really are thus unitary. At least we should be open to evidence that such unity is illusory. People used to think there was only one sun in the universe, but more careful investigation revealed a plurality of suns; might the same thing be true of the self in our own personal universe?
Let me list some putative reasons for dissent from the common assumption: the Freudian division into ego, id, and superego; the phenomenon of multiple personality; brain bisection experiments; modular conceptions of mind; the theatrical conception of the self; division into private and public self; a general sense of self splintering (R.D. Laing, The Divided Self). I don’t propose to discuss each of these in detail; I am more interested in the general idea of multiples selves. I certainly think it is logically possible for a single organism to house more than one psychic entity deserving the name of self; and I think there is good empirical evidence that this is normal for ordinary adult humans. I am with Erving Goffman (and William Shakespeare) in believing that a given individual presents a number of distinct selves in different social contexts, and that these are deeply entrenched. The person is something dramatically constructed—and we can construct a plurality of these things. I myself have always felt that I am made up of three distinct selves—an intellectual self, an athletic self, and a musical self—with little overlap between them; and I fancy I am not alone in having this kind of impression. Is my impression to be disputed? I also wrote a novel, The Space Trap, in which I played with the idea of a phobic self and an imaginary self in addition to the self we ordinarily recognize. Such ideas are quite common in writers trying to represent the complexity of human psychological reality. People feel they are not the simple unity that we tend to speak of; there are significant divisions and separations (hence the famous Walt Whitman remark, “I contain multitudes”). Just as people feel themselves to change dramatically over time, becoming “a different person”, so they feel that at a given time there is a plurality lurking inside. Pathological conditions like schizoid personality or multiple personality are not so far from the norm, maybe just extreme cases of it. If someone sincerely believes himself to have a divided self, what evidence can be used to refute him? What kind of counting procedure would undermine such a claim? Might there not be degrees of division with the normal case of personal separation just at the far end? Whence the dogmatic conviction that there must be only one self each? We have got used to the idea that we possess more than one mind, what with the unconscious and generalized modularity, so why should the self be treated as uniquely unitary? If I contain many minds, don’t I thereby contain many selves? If Freud were right about the unconscious, surely he would have discovered another self in us in addition to the conscious self—an autonomous agent with its own agenda. True, the conscious self that is encountered in introspection has a certain salience, but why should that determine the full extent of our selfhood? And that self might divide into a number of sub-selves upon closer examination. We are often torn, internally conflicted, and doesn’t that suggest a separation of selves? No one ever told the genes, or our life experiences, that they were to construct only a single self, so the possibility is open that they construct a plurality of selves uneasily (or easily) conjoined. We are more like a constellation of selves than a single unified self, a galaxy not a solitary star.
If this is so, then our identity through time consists of the persistence of many selves, not one. There is not a single self that exists from one moment to the next but a plurality of selves. Some of these selves may perish while others march on; all may perish at some point to be replaced by new ones. What we call our personal identity, and picture as a single persistent capsule, is really a mixture of separate elements held tenuously together: an identity of selves in the plural not the singular. Conceivably, these selves might have different conditions of identity: for example, there may be a biological self fixed by the genes that is tied to the constitution of the organism, existing alongside a number theatrical selves freely constructed to serve suitable social purposes and revocable at will. A theatrical self may disappear at a certain time when the context no longer demands it, while the biological self goes on regardless. Once we accept a plurality of selves we have the possibility of separate existence through time. It is really too simple to speak of “personal identity” as if we had a single well-defined thing called a “person” whose identity is at issue; the human psyche is too complex for that. Surely we can imagine a being that regards himself as such a plurality and speaks spontaneously of one of his selves going out of existence while others continue. If we insist on his answering the question whether he survived such and such an event, he might give us a puzzled look and reply, “Well, this self and that self survived, though that other one didn’t”. For this being it would be wrong by stipulation to speak only of a single self that survives or fails to. To what extent we approximate to his condition is an empirical question, and one that has a good deal of evidence in its favor.
I believe it is true to say that we experience our body as more of a unity than it really is. It comes as a surprise to discover all those separate organs each doing its specific job—and illness can deliver a jolt to our assumption of unity. If we ask after its persistence conditions, we quickly come to see that many organs are involved, and some can survive what others may not. If we insist on asking whether the body survives such and such an event, we can see that this question is too simple, given the complexity of the body (the plurality of its organs). The person is a bit like that: in principle some parts may survive while others perish (consider Alzheimer’s). I can lose one hand while retaining the other because I have two hands; why couldn’t I have more than one self where each can survive separately? If the brain realizes human personality in more than one location, then damage to one location may destroy one instance but leave another: wouldn’t this be the loss of one self and the retention of the other? Here we would have different tokens of the same type, or similar types, but different types may also coexist with one another. It may be convenient to talk as if we are a single entity, as it is convenient to talk of the body as a single entity, but both are made up of other units. What we call the self is really a plurality of distinct self-like entities. 
There is a plurality of types of self; there is a plurality of possible selves corresponding to each human (and animal) individual; and there is a plurality of actual selves within each individual. There is not just the human type of self; there is not just a single possible self for each individual; and there is not just a single actual self for each individual.
 I haven’t considered so-called psychological continuity theories in relation to hypothetical persons. This is because I am not convinced such theories have ever been properly formulated, and because they seem open to obvious counterexamples concerning sufficiency (continuity is a “cheap relation”). And couldn’t there be beings that revel in their psychological discontinuities, changing their beliefs and desires dramatically from day to day? They might regard this flexibility as essential to their identity.
 Of course, the parts of the body are not themselves bodies but organs of the body, and parts of the self may also not themselves be selves; but there is reason to accept that some parts of what we call our self are also self-like. If they existed alone, we would still call them selves.