The I in Me

By Thomas Nagel
London Review of Books, Vol. 31 No. 21

November 5, 2009

Edited by Andy Ross

Selves: An Essay in Revisionary Metaphysics
By Galen Strawson
Oxford University Press, 472 pages

Galen Strawson argues that selves exist and that they are not human beings. He holds that your experiences are events in your brain, and that if there is a self which is their subject it too is in the brain. He contends that there are two uses of the word 'I': one referring to the public human being, the other to the subject of consciousness.

Strawson begins from the essential inner polarity of consciousness: all conscious experience is experience for a subject. He says there cannot be thinking without a subject. The character of an experience or conscious thought is what it is like subjectively for someone or something to have it.

The subject presented in experience must be a single mental thing. However complicated the contents of my consciousness at any moment, all of it is co-present to a single subject. If selves exist in reality, according to Strawson, they must be mental individuals of this kind.

In one sense, the term 'I' refers to an inner thing with a temporal extension. You as subject have existed approximately since the birth of the human being that you also are, and will continue to exist until his or her death. Experience presents us with a sense of the temporal extension of the self, through memory of the past and anticipation of the future.

Strawson contends that this natural belief in the persistence of the self is probably an illusion. If the self is a single mental thing, how can it persist across temporal gaps in consciousness? If we pass part of each night in dreamless sleep, what is it, apart from the human being, that loses consciousness late at night and regains it in the morning?

Strawson agrees with Descartes that the self is always conscious. Strawson interprets this not as the claim that the self is a type of persisting substance but rather that the self is nothing but persisting, unified consciousness. The persistence of the self over time demands a diachronic mental unity analogous to the synchronic mental unity of the subject of experience at any one time.

Strawson concludes that the self does not persist across gaps in consciousness. It also doesn't persist across the shifts in the content of consciousness that occur constantly in the course of waking life. He holds that the subjective experience of the self does not require that it persist beyond the lived present. It does not seem to him that his present self existed in the past, or will exist in the future:

"When I consider myself in the whole-human-being way I fully endorse the conventional view that there is in my case — that I am — a single subject of experience — a person — with long-term diachronic continuity. But when I experience myself as an inner mental subject and consider the detailed character of conscious experience, my feeling is that I am — that the thing that I most essentially am is — continually completely new."

Because the diachronic unity of the self, like its synchronic unity, must be a purely experiential unity, he concludes that the self exists only if experience exists of which it is the subject. This thing cannot be distinguished from its properties, and those properties are exhausted by the experience, which is in turn identical with the experience's contents. The self which exists at any time is simply a unified experiential process or episode.

If each self is as impermanent as that, it has no ontic depth. The self that is the subject of your present experience does not know algebra or French, or how to make an omelette, and it does not have political convictions. But such things, says Strawson, can find an adequate home not in the fleeting sequence of selves but in the persisting human being, with its persisting brain.

Strawson asks us to give up the powerful conviction that the I who is the subject of my present experience has existed for a long time, that it was also the subject of the experiences I remember from the past, and that it will be the subject of the experiences that the human being who I am will undergo in the future.

Strawson is convincing as to the inadequacy of the argument that the reference of 'I' is entirely parasitic on the public criteria of identity for human beings. I do not think we can resist his basic point that there are two uses of 'I', and that one of them refers to the inner subject. I suspect that many children have experienced with amazement the realization that the self with which they are so familiar inhabits a particular public human being.

AR  Galen is a creative and thoughtful philosopher. In the year 2000 I sent him a copy of my first Tucson essay on consciousness (chapter 4 in Mindworlds) and I am happy to find that his position now bears some similarity to mine. I agree that from the standpoint of the logical subject(s) of experience we are born anew in each new moment of specious present.

In my gloss, each such subject is a waystation in the evolution, as repeated reincarnation from the ashes of its own ancestors, of an ongoing macrosubject that emerges like an empire from its subjects, as a tradition in which the microsubjects live and die. The big subject, the "I" of our everyday lives from human birth to human death, is an empire of moments. Each moment is a mirror to a constellation of experiential elements, qualia perhaps, that come together in a synthetic unity of apperception that is no sooner born than it begins to dissolve and die.

These moments have a physical carrier. On this part of the story I part company with Galen. I see a straightforward extension of present-day physics as sufficient in principle to begin the process of understanding these moments of experience. The moments of synthetic unity are embodied in photonic wavefronts. These wavefronts are envelope waves radiating from the decahertz vibrations that animate the neocortex as synchronous waves of neural firing sweep around thalamocortical loops to integrate the stimulated neural groups whose combined quality provides the combinatorial key for a moment of experience in memory. A qualitative duplicate can be reconstituted later by again firing the groups specified by the key.

Once that physics has been worked out and applied to understand the generation of moments of conscious experience, we shall see that similar mechanisms can work in principle in nonhuman and nonbiological substrates. Perhaps we shall find that remote analogs of consciousness are sustained already in the physical world. This is the panpsychism of which Galen dreams and which I see as less remote from current physics than he imagines.

On human selves, my story recombines with Galen's. The human brain and body are what enable the otherwise isolated moments of experience to come together in such harmony that they merge their subjective identities far enough to create an approximately integrated and unified macrosubject, the "I" of our everyday lives.

These moments of subjective apperception are indefinitely extensible. Here again I am eager to go beyond Galen's account. Two or more people can combine their personal self-moments almost as readily as our neural self-moments combine in our own selves. When different people merge their momentary selves in shared experiences of now, greater unities become possible.

At the end of that line of thought lies a global self, whose unity results more from the technology of information processing and telecommunications than from the biology of neural signal processing. But that's another story, one I plan to tell next year.