فصل 14

chapter 14

The Prince and the Cobbler

John Locke and Thomas Reid

What were you like as a baby? If you have one, look at a photograph taken at the time. What do you see? Was that really you? You probably look quite different now. Can you remember what it was like being a baby? Most of us can’t. We all change over time. We grow, develop, mature, decline, forget things. Most of us get wrinklier, eventually our hair turns white or falls out, we change our views, our friends, our dress sense, our priorities. In what sense, then, will you be the same person as that baby when you are old? This question of what makes someone the same person over time is one that vexed the English philosopher John Locke (1632–1704).

Locke, like many philosophers, had wide interests. He was enthusiastic about the scientific discoveries of his friends Robert Boyle and Isaac Newton, was involved in the politics of his day and also wrote about education. In the aftermath of the English Civil War, he fled to the Netherlands when accused of plotting to murder the newly restored king, Charles II. From there he championed religious toleration, arguing that it was absurd to try to force people to change their religious beliefs through torture. His view that we have a God-given right to life, freedom, happiness and property influenced the founding fathers who wrote the United States Constitution.

We don’t have any photographs or drawings of Locke as a baby. But he probably changed quite a lot as he grew older. In midlife he was a gaunt, intense-looking figure with long straggly hair. As a baby, though, he would have been quite different. One of Locke’s beliefs was that the mind of a newborn is like a blank slate. We don’t know anything when we are born, and all our knowledge comes from our experience in life. As the baby Locke grew into the young philosopher, he acquired all kinds of beliefs and became the person we think of now as John Locke. But in what sense was he the same person as the baby, and in what sense was the middle-aged Locke the same person as the young man?

This sort of problem doesn’t just arise for human beings wondering about their relationship to their past. As Locke noticed, it can even be an issue when thinking about socks. If you have a sock with a hole in it and you patch that hole up, and then patch up another hole, eventually you might end up with a sock that consists just of the patches, with none of the original material there at all. Would that still be the same sock? In one sense it is, because there is a continuity of parts from the original to the completely patched up sock. But in another sense it isn’t the same sock, because none of the original material is there. Or think of an oak tree. An oak tree grows from an acorn, loses its leaves each year, gets bigger, branches fall off, but still remains the same oak tree. Is the acorn the same plant as the sapling, and the sapling the same plant as the huge oak?

One way of approaching the question about what makes a human being the same person over time would be to point out that we are living things. You are the same individual animal that you were as a baby. Locke used the word ‘man’ (meaning by that ‘man or woman’) to refer to the ‘human animal’. He thought it was true to say that over a life each of us remains the same ‘man’ in that sense. There is a continuity of the living human being that develops in the course of its life. But for Locke being the same ‘man’ was very different from being the same person.

According to Locke, I could be the same ‘man’, but not the same person I was previously. How could that be? What makes us the same person over time, Locke claimed, is our consciousness, our awareness of our own selves. What you can’t remember isn’t part of you as a person. To illustrate this he imagined a prince waking up with a cobbler’s memories; and a cobbler with a prince’s memories. The prince wakes up as usual in his palace, and to outside appearances is the same person he was when he went to sleep. But because he has the cobbler’s memories instead of his own, he feels that he is the cobbler. Locke’s point was that the prince is right to feel that he is the cobbler. Bodily continuity doesn’t decide the issue. What matters in questions about personal identity is psychological continuity. If you have the prince’s memories, then you are the prince. If you have the cobbler’s memories, you are the cobbler, even if you have the body of a prince. If the cobbler had committed a crime, it would be the one with the prince’s body that we should hold responsible for it.

Of course in ordinary cases memories don’t switch like that. Locke was using this thought experiment to make a point. But some people do claim that it is possible that more than one person can inhabit a single body. That is a condition known as multiple personality disorder, where it appears that different personalities are present within a single individual. Locke anticipated this possibility and imagined two completely independent persons living in one body – one present by day, the other only at night. If these two minds have no access to each other, then they are two persons, on Locke’s account.

For Locke, questions of personal identity were closely connected with moral responsibility. He believed that God would only punish people for crimes they remembered committing. Someone who no longer remembered doing evil wouldn’t be the same person who committed the crime. In everyday life, of course, people lie about what they remember. So if someone claims to have forgotten what they’ve done, judges are reluctant to let them off. But because God knows everything, he will be able to tell who deserves punishment and who doesn’t. A consequence of Locke’s view would be that if Nazi-hunters track down an old man who in his youth had been a concentration camp guard, the old man should only be held responsible for what he can remember, and not for any other crimes. God wouldn’t punish him for the actions he’d forgotten about, even if ordinary courts wouldn’t give him the benefit of the doubt.

Locke’s approach to personal identity also gave an answer to a question that vexed some of his contemporaries. They worried about whether you needed the same body to be brought back to life in order to go to heaven. If you did, what would happen if your body had been eaten by a cannibal or a wild animal? How would you get all the body parts back together to be raised from the dead? If the cannibal had eaten you, then bits of you would have become part of him or her. So how could both the cannibal and the cannibal’s meal (i.e. you) both be restored as bodies? Locke made clear that what mattered was that you were the same person in the afterlife rather than the same body. On his view you could be the same person if you had the same memories, even if these were attached to a different body.

One consequence of Locke’s view is that you probably aren’t the same person as the baby in the photograph. You are the same individual, but unless you can remember being a baby, you can’t be the same person. Your personal identity only extends as far back as your memory. As your memories fade in old age, too, the extent of what you are as a person will also shrink.

Some philosophers feel that Locke went a bit far with his emphasis on self-conscious memory as the basis of personal identity. In the eighteenth century, the Scottish philosopher Thomas Reid came up with an example showing a weakness in Locke’s way of thinking about what it is to be a person. An old soldier can remember his bravery in a battle when he was a young officer; and when he was a young officer he could remember that he had been hit when as a boy he’d stolen apples from an orchard. But in his old age, the soldier can no longer remember this event from his childhood. Surely this pattern of overlapping memories would mean that the old soldier was still the same person as the boy? Thomas Reid thought it was obvious that the old soldier was still the same person as the young boy.

But according to Locke’s theory the old soldier was the same person as the young brave officer, but wasn’t the same person as the young child who was hit (because the old soldier had forgotten about that). Yet, also according to Locke’s theory, the young brave officer was the same person as the child (because he could remember his orchard escapade). This gives the absurd result that the old soldier is the same person as the young brave officer, and the young brave officer is the same person as the child; but at the same time the old soldier and the child are not the same person. As a matter of logic that doesn’t work at all. It is like saying A = B and B = C, but A doesn’t equal C. Personal identity, it seems, relies on overlapping memories, not on total recall as Locke had thought.

Locke’s impact as a philosopher rests on far more than his discussion of personal identity. In his great work An Essay Concerning Human Understanding (1690), he put forward the view that our ideas represent the world to us, but that only some aspects of that world are as they seem. This stimulated George Berkeley to come up with his own imaginative account of reality.