According to Pausanias, inscribed above the temple to Apollo at Delphi were the wise words Know Thyself. This injunction has been referenced by everyone from Plato to the oracle in the Matrix trilogy. As philosopher Derek Parfit has argued, one can read the history of Western moral philosophy as an ongoing story about why care for the self is what ultimately matters. Think of Grecian arguments about the need to develop a beautiful soul, the Christian demand that we make ourselves into a pure individual worthy of salvation, the Romantic veneration of self-expression, and our postmodern fixation on identity. However, what exactly is the self? If you believe that each individual human is fundamentally a self in some essential sense, then to ask that is to question what we are. There are many ways to answer this. One popular approach is literary and psychological. Great literature from The Iliad through to the works of Tolstoy and Virginia Woolf has asked how our sense of self evolves. The richest works illuminate this theme by highlighting the universal aspects of a single individual’s development over time.
There are five main competing philosophical conceptions of the self. The first four view the self as located in the soul, the body, the brain and the mind respectively; the last contends that we have no real self at all. The moral and political arguments associated with each position may help clarify some of the fierce current disputes about identity and the purpose of life in postmodernity.
The Self Is the Soul
It has been proven to us unequivocally that if we are ever going to gain clear knowledge of something, we must separate ourselves from our body and examine with our soul only, each thing on its own. It seems then that it will only be possible for us to attain that which we desire and love the most, which is wisdom, after we die because, obviously, as this enquiry proves to us that we cannot attain it while we are alive. Because if it is not possible to learn anything clearly when we are attached to the body, we must say that only one of two things is possible: either it is impossible to learn anything clearly anywhere at all or else, it is only possible after we die, since then the soul will be free of the body unlike before, when we were alive.—Socrates, in Plato’s Phaedo
Perhaps the single most influential theory of the self in western philosophy and the monotheistic traditions is that we are fundamentally souls. While body and mind are fungible features of our existence, changing over time, the soul is an eternal center that determines what we are. Associated with this conception of selfhood is a dualistic model of temporality, wherein our experience of time as succession is really just the moving image of eternity. Our temporal existence, which includes bodily and mental change and decay, is less real than what persists eternally, including the soul. The political and moral implications of this are well known. Our time on this earth is finite and less real than the eternal realm. This means that we should be far less attentive to our worldly needs, since these are ultimately ephemeral. Instead, our moral and political energies should be directed towards connecting with the eternal within us and within existence generally. This means improving the quality of our soul by apprehending objects such as the Platonic forms of justice or God.
Beyond the psychological appeal of eternal life, the soul theory of the self has many virtues. It offers an economical explanation of the feeling of being a persistent self over time: while our thoughts and body can change dramatically, it is difficult to escape the sense that we remain inexorably the same entity over the course of life. Plato argues that our eternal nature also explains how we can apprehend abstract entities such as number, which don’t have any clear empirical correlates. But the soul theory has many problems. The argument for the soul is almost always inserted as a way of explaining something we do not fully understand: our capacity to comprehend numbers, for example. But just because we cannot understand some feature of ourselves doesn’t justify any speculative answer we may put forward. The argument that we have a soul is also subject to Nietzschian criticisms: it shields the weak from the troubles of the world and causes them to regret life. Perhaps life is tragic and finite and we should simply steel ourselves to make the best of it.
The Self Is the Body
Some argue that Plato and his descendants are fundamentally wrong. There is no soul: we are just bodies. French phenomenologist Maurice Merleau-Ponty has claimed that much of western thinking has been a concerted effort to avoid considering the body. But, with the advent of scientific modernity, we have gradually moved towards a more materialistic perspective, reflected in contemporary injunctions to embrace body positivity and to lavish incessant care on the body. The problem with this perspective has been highlighted by Shelly Kagan. When we claim the body is the self, we do not mean the entire body. As we age, the cells in our body die and are replaced, but we would not say that our self dies and is replaced by a copy. We may even replace entire organs through transplants. This suggests that some parts of the body take priority over others when it comes to selfhood.
The Self Is the Brain
The argument that the self is the brain is more persuasive than the argument that it is the entire body. If a person’s brain were removed and destroyed, but medical technology kept the remainder of the body alive, we would probably not say that the self that was located in that body still existed, since its material locus had been eradicated. By contrast, it is plausible to think that, should we manage to successfully transplant a living brain into another body, the person who woke up from the operation would be the individual carried within that brain’s grey matter. This materialist conception prompts a more materialist politics. It suggests that we are, contra Plato, finite beings composed of matter that exists within time. We may be remarkably sophisticated relative to simpler forms of matter, but there is no ontological difference between ourselves and the physical elements which make up both the world and our brains. This suggests that the point of life is happiness in the here and now, which is probably why people espousing this view tend to emphasize utility maximization and wellbeing as central moral goals.
There is a lot going for the brain view of the self. It meshes with our scientific outlook, and can grow in complexity and richness as our empirical understanding of the brain increases. But it is not without serious limitations—the brain theory of the self and consciousness cannot account for qualia. Frank Jackson’s thought experiment involving Mary the color scientist is helpful in this regard. Imagine a woman named Mary, blind from birth, who grows up to be a neuroscientist specialising in the mechanics of color vision. Mary would still not know what it was like to see the color blue—despite knowing how the brain apprehends colors. This suggests a qualitative aspect to selfhood and experience, which is not captured by the materialist outlook. As Saul Kripke argues in Naming and Necessity, the material facts associated with a brain’s experience of pain tell us little about what it is actually like for a self to experience pain. Or consider the more grotesque scenario presented by Derek Parfit. We discover that both hemispheres of the brain carry all that is required for selfhood, independently. We then halve the brain of a single individual and put each half into a separate body. Despite having effectively the same brain, it would be difficult to claim that each individual had the same self, since each would go on to have her own unique memories and experiences.
The Self Is the Mind
These problems with the materialist outlook go back a long way and this is why many remain attracted to Cartesian style solutions, which posit that selfhood is located in some feature of the mind. For Descartes, a mysterious ego inhabits the body and gives it life. For the empiricist Locke, it is our memories that generate selfhood. The fact that I can recall being a child who went to school, while being an adult working at a job, shows that I have remained the same self over time. Some claim that personality determines selfhood: I am Matthew McManus not just because I have memories of always having been so, but because I identify as such and have ambitions and desires unique to myself, which are projected into the future. For Kant, we have an outer self, which exists in the phenomenal world of physical things and perceives them, and an inner self, which includes our rational intellect and will to act. This inner self is far more crucial, since it forms the basis of our dignity and freedom. To a materialist, such arguments seem far fetched and reminiscent of Platonic speculations. Critics like Daniel Dennett insist that the mind and thus our sense of self is produced by processes in the brain. But some philosophers, like David Chalmers, call upon science to broaden its understanding to incorporate non-physical features like consciousness.
The idea that the mind is the basis of the self is appealing—indeed, this is the view I myself subscribe to. It seems capable of incorporating elements of the world, such as our experience of qualia, which a purely materialist view cannot explain. It also explains why possessing the same brain is not the same as being the same self, as Parfit’s thought experiment demonstrates. The argument that the self is not merely the brain also has moral appeal. It suggests that, although we are physical objects, elements of our selfhood cannot be explained exclusively in those terms—such elements might include human freedom and creativity, which may be inexplicable to deterministic materialism. But the position also shares many of the problems of Platonism: the fact that materialism cannot firmly explain qualia doesn’t justify positing speculative entities, like a non-material mind. In Reasons and Persons, Parfit also raises another objection: even the mind may not provide a firm basis for selfhood. Consider this thought experiment: I enter a Star Trek-style transporter, with the intention of beaming down to Mars. I discover that, although the machine has cloned my mind and body and created a copy on Mars, the originals on my spaceship will swiftly be destroyed. For a brief moment, though, there are two people with the same body, brain and mind. Parfit points out that it would be little consolation to the original to know that someone with his mind—in particular, with his memories—was going to continue. The original would still feel that he was dying and that his self was being destroyed and replaced by a mere duplicate.
There Is No Self
For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe any thing but the perception. When my perceptions are remov’d for any time, as by sound sleep; so long am I insensible of myself, and may truly be said not to exist. And were all my perceptions remov’d by death, and cou’d I neither think, nor feel, nor see, nor love, nor hate after the dissolution of my body, I shou’d be entirely annihilated, nor do I conceive what is farther requisite to make me a perfect non-entity. If any one upon serious and unprejudic’d reflexion, thinks he has a different notion of himself, I must confess I can reason no longer with him. All I can allow him is, that he may be in the right as well as I, and that we are essentially different in this particular.—David Hume, A Treatise Concerning Human Nature
The most radical position is that there ultimately is no self: that the self is an illusion or a cultural conceit. This is often presented as the position of the Buddha, in his insistence that we seek a selflessness that will free us from illusion. It is also the position of the great empiricist David Hume, who pointed out how ephemeral the idea of selfhood is. We are never able to identify what the self is in the world. Even when looking inward, we can only apprehend the different perceptions we have experienced over time: at one moment eating, at another writing, touching a table and so on. Nowhere amid these perceptions do we find the self. Derek Parfit also claims that we should move away from thinking that we have a fixed self. This has moral consequences, Parfit argues, since, once we realize that the self is ephemeral, we have few reasons to prioritize it. It is far more important to become more selfless and giving. Rather than prioritizing our own needs, to placate a self that has a thin existence at best, we should donate significant resources to trying to improve the world. Richard Rorty makes a similar comment when he enjoins us to stop thinking of ourselves as having Cartesian minds, and denies scientific materialism’s ability to explain all human workings by appealing to the brain.
This position resolves the problems with selfhood by dissolving them. Arguing about selfhood, in this view, is like arguing about what a unicorn really is. The question cannot be answered because there is no self to analyze. It also enjoins us to embrace a more impartial moral outlook, by recognizing that we as individuals are unimportant and should therefore stop being self-centered. However this sidesteps the qualitative problems highlighted above: experiences like color and pain and emotions like love and hate seem irrevocably attached to a self who cares about what is happening. This has moral implications, since it is impossible to push impartiality so far that it becomes mere indifference. Morality has an irrevocably practical aspect, as Kant observed. I wish to act morally because I feel it is important for me, as someone who cares about his actions and the impact they have on others. If there were no selves, it would be difficult to locate a source of action or suggest that what occurs in the world matters. As Shakespeare puts it, “There is nothing good or evil, but thinking makes it so.” Thinking makes it so because what happens is relevant to us, and we weigh it accordingly.