Consider for a moment some differences between you and everybody else. You look out of your own eyes but you look at or into other people’s eyes. You have never seen your own face, nor the back of your own head. In the case of just one human body (the one called your own) you feel yourself to be wholly or largely co-extensive with it. Perhaps you are inside your body or perhaps you are your body, looking out of it. In just this body but nobody else’s you experience sensations and thoughts. The rest of the world seems physically arranged around you, with your body at its centre. You cannot in the normal course of things encounter your body as one object amongst others in the external world. This, on the other hand, is just how we encounter other people’s bodies, as living, speaking, expressive, but as over there.
These strange yet intimate phenomenological and physical facts are symptomatic of being oneself. We are so used to thinking in a general or abstract way that we fail to notice that something is me. Once noticed, this fact is at once obvious and extremely puzzling. For many people, for much of their lives, being what they are is an obstacle to noticing what they are.
Noticing one’s own existence as one’s own makes possible the understanding of a group of profound and interrelated philosophical questions: What is it for something to be me? Why is something me? What exactly have I claimed about something—a mind, a brain, a body, a whole human being—when I have claimed that it is me?
‘What am I?’ does not necessarily capture the question. I am no doubt many things (a human being, a man, a biological organism, a thing that thinks, the only person born in that place at that time, the only person with that genetic make-up, etc.). The problem is that none of these facts says what it is for that thing to be me. ‘What am I?’ does capture the question if it means ‘What is it for something to be me?’
The prospects for scientific attempts to answer these questions look grim. This is partly because descriptions of my existence and the theories of science are antithetical: I have a capacity to make choices, science is essentially deterministic. I have a past, present and future, science is tenseless. I have a psychological interiority, science only ever explains physical exteriority. Science cannot explain me because I am the opposite of what science says there is.