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[Article updated on 21 June 2019.]
Personality can be defined as a person's pattern of thinking, feeling, and behaving. All well and good, but what happens if we dig a little bit deeper? What is "a person" and, more precisely, what does it take for a person no longer to be the same person? Are you the same, identical person at all times? Are you the same person that you were a minute, a day, a year, 10 years ago? If so, what do you have in common with the person that you were 10 years ago?
A person is a mental being, but not just any mental being, because many animals are also mental beings. A person is a self-conscious mental being who, according to the English philosopher John Locke (1632–1704), is "a thinking, intelligent being, that has reason and reflection, and can consider itself as itself, the same thinking thing, in different times and places." According to this definition, you are a person because you can think about yourself in the past, future, and conditional, and in a variety of different places: "In February I might go on a holiday to India," "Last summer I went on holiday to Florida," "Last month I could have won the lottery, if only I had bought a ticket."
If a person is "a self-conscious mental being," what is it that makes him so? Is it his body, his brain, his "soul?" Imagine that he has a serious accident that leaves him lying brain-dead on a hospital bed. His body is still alive but he is no longer self-conscious nor can he ever be again. Is he then still a person? If not, then his physical body cannot be that which makes him a person.
Let us for a moment turn to the second aspect of the question, what it takes for a person no longer to be that same person. Some philosophers have argued that a person at a time A can be the same as a person at a time B because his body or brain is the same body or brain at both times, in the sense that they are spatiotemporally continuous (continuous in space and time). Other philosophers have argued that this is not the case and that a person at a time A can be the same as a person at a time B because they are psychologically continuous, that is, the mental states of the person at a time B derive or descend from the mental states of the person at a time A.
To help elucidate this problem, the American philosopher Sydney Shoemaker (born 1931) asks us to imagine that science has advanced to such an extent that brain transplants are now possible. Two men, Mr. Brown and Mr. Robinson, each have their brain removed and operated on at the same time. However, a poorly trained assistant inadvertently puts Brown's brain into Robinson's head, and Robinson's brain into Brown's head. One of these men dies, but the other—say the one with Brown's brain and Robinson's body (let's call him "Brownson")—eventually regains consciousness. When asked his name he replies "Brown." Subsequently, he is able to recognize Brown's wife and family and to recount Brown's childhood memories, but he cannot recognize Robinson's wife and family nor recount Robinson's childhood memories.
Who then is this man Brownson with Brown's brain and Robinson's body? If he is Brown, as most people would argue, then a person cannot be reduced to a body, as indeed the earlier brain-dead scenario may already have demonstrated. This leaves us with two possibilities: Either Brownson is Brown because he has Brown's brain, or he is Brown because he is psychologically continuous with Brown.
To decide between these two possibilities, let us carry our thought experiment further still. As many people have survived with half their brain destroyed, let us imagine that Brownson's brain (or indeed anyone's brain, say Smith's) is now divided into two equal halves or hemispheres and that each hemisphere is transplanted into a brainless body. After the operation, two people awake who are both psychologically continuous with Smith, and who have the same character and memories as Smith. If both people are psychologically continuous with Smith, are they both Smith? If so, then are they also each other? Most people would argue that, even though the two people may be very similar at the time of awaking from the operation, they are in fact two people and not one and the same.
So what can we conclude from this mind-boggling discussion, and what are the implications for personality? It seems that what makes you a person, what makes you "a self-conscious mental being," depends causally upon the existence of your brain but at the same time amounts to something more than just your brain. What this might be is unclear, and perhaps for a reason.
As human beings, we have a tendency to think of our personhood as something concrete and tangible, something that exists "out there" in the real world, and that therefore extends through time. However, it is possible that personhood is in fact nothing more than a product of our minds, merely a convenient concept or schema that enables us to relate our present self with our past, future, and conditional selves.
According to the Buddha, the failure to recognize this illusion of the self is the source of all ignorance and unhappiness. It is by renouncing the self—that is, by dropping his ego defences and committing metaphorical suicide—that a person can open up to different modes of being and relating and become a pure essence of humanity. Only then is he free to recast himself as a more mindful, joyful, and productive person, and, in so doing, attain the only species of transcendence and immortality that is open to man.
Neel Burton is author of Hide and Seek: The Psychology of Self-Deception.
