Who Am I?

Over a lifetime all of us change to an extraordinary degree. From a physical perspective we start off as a little bundle about 50 centimeters high, with cherubic features and elastic soft skin, and then we may end up, some 90 years later, as a stooped, gray, liver-spotted, 180-centimeter high structure. In the intervening period every single cell in our body will have been replaced, often many times over, and we'll have gone through all kinds of experiences that perhaps leave almost no trace in memory.

The twenty five-year-old won't remember most of what the five-year-old felt so strongly about. The sixty seven-year-old will only dimly recall what was on their mind as they approached 30. We carry the same name throughout our lives, and consider ourselves as a relatively stable unitary entity, but is it really right to think of ourselves as the same person?

Once one puts it under a philosophical microscope the issue of personal identity emerges as far trickier than at first assumed. So, in what ways could we be said to be continuous throughout time? What does guarantee that we can plausibly think of ourselves as the same people over a lifetime?

Just where is personal identity located? A standard assumption is that it's our body that guarantees our personal identity. This is the theory that a key part of what makes me 'me' is that I'm housed in an identical body, but philosophers like to push this assumption around a little.

Imagine if I lost all my hair. Would I still be me? Yes, sure.

What if I lost a finger? Yes! A leg?

Definitely. Now, what if a malevolent demon appeared, and told us that we'd have to lose every part of our bodies, but could keep just one bit. .

. Which bit would it be? Few of us would pick our elbow, or belly button.

Almost all of us would pick our brains, and that tells us something interesting. We assume, implicitly, that some bits of our bodies are more 'me'ish, closer to the core of personal identity than others, and the most 'me'ish of all the bits are our brains. Christianity runs a version of this thought experiment; it asks us to think what will happen after our death, and it imagines a separation of the body, ultimately not that significant, and the ongoing survival of a more modest, precious bit that it calls the soul.

There's another version of this thought experiment that two lovers can play. In the early throes of love, two people who've gone to bed together might ask: "What do you really like about me? " The wrong answer is to say: "your fabulous breasts" or "your amazing muscular arms".

Breasts and chest don't ultimately feel 'me'ish enough to be a respectable answer. It seems we want to be loved for something closer to our real self. Perhaps our soul, or our brain.

Now let's push the thought experiment further: What bit of the brain is actually most crucial to being 'me'? Let's imagine that I have a bump to the head and lose my ability to play table tennis. Am I still myself?

Most of us would say "yes, sure. " What if I once spoke Latin and lose the ability, or forgot how to cook asparagus with a light mayonnaise sauce. Would I still be me?

Yes. In other words, technical capacities don't feel very close to the core of personal identity. What about other kinds of memories?

A big part of making me 'me' tends to be my store of memories. I remember the carpet in my bedroom when I was growing up, or the girl I was in love with at University, or the weather over Sydney as we came in to land for my first Australian book tour. But what if these memories all vanished as well?

Could I still be me? One view is: Possibly. So long as something else remained, and that thing we can call my character.

In other words, if my characteristic way of responding to situations, my sense of what is funny, wise, interesting or important remained the same, I can still, in some fundamental way, claim to be the same person. My memory store of feelings and behaviors might be gone, but I could be assured of continuing to feel and behave in compatible ways in the future. Those around me would need to keep reminding me of stuff that had happened, but they would still recognize me as me.

A fascinating idea comes into view: Personal identity seems to consist not in bodily survival; I could be put in somebody else's body, or live in a jar and still be me. Nor in the survival of memory; I could forget everything and still be me. But in the survival of what we are here going to call 'character'.

This is an idea attributed to the English philosopher John Locke, who famously wrote: "Personal identity is made up of", what he called, "sameness of consciousness". If a demon offered us a choice between remembering everything but feeling and valuing very differently, or feeling and valuing the same sorts of things but remembering nothing, most of us would, Locke suggests, choose the latter. So, if we have to boil personal identity down to its essence it seems to come down to values, inclinations, and temperament.

Let's think of death with all this in mind. The standard view of death is that it's sad because it means the end of our identity. Now, it certainly does mean the end if we identify identity with the survival of our bodies, or with that of our memories.

But if we think that who we are is to a large degree about our values, and characteristic loves and hates, then we are, in a sense, granted a kind of immortality simply through the fact that these will continue to live on in our species, as a whole, lodged here and there, outside of their present home. Perhaps what we have learned to call 'me' was only ever a temporary resting place for a set of ideas and proclivities that are far older, and are destined to live on far longer than our bodies. .

. We might attempt to be less sad about death by letting go of the idea that we are a particular constellation of physical features. We are always, in a sense, far longer lasting, far more transgenerational as a bundle of inclinations, and ideas.

We will continue to crop up and live wherever those ideas, that are most characteristic of us will emerge, as they must, in the generations that are to come. Focusing in on questions of identity has the paradoxical, and rather cheering effect of making us both less attached to certain bits of us, and more confident that the really important things about who we have been will survive, in a way, long after our bodies have returned to dust and our memories have been obliterated.