Readings for this section: Williams, “The Self and The Future”
There is a really important caveat to make here, which Bernard Williams is keen to highlight in the case of the brain transplants.
To illustrate this, Williams begins by describing a version of a brain transplant case involving two people, Adam and Brian, who are shortly to have their brains exchanged.
Now before the exchange takes place, an experimenter tells the two that after the brain swap has taken place, one of the two bodies will be rewarded with $100,000 and the other body will be tortured. Both Adam and Brian are asked to choose which outcome they would like to happen.
Suppose Adam chooses that the Brian-body should be given the money and the Adam-body tortured, and suppose that Brian chooses that the Adam-body should be given the money and the Brian-body tortured.
Of course, these two choices are incompatible, so the experimenter is going to have to go with one of the two requests and against the others – let’s say he goes with Adam’s request and gives the money to the Brian-body and tortures the Adam-body.
After the operation, how will the people inhabiting the two bodies respond?
The Brian-body: After the operation, the experimenter gives the money to the Brian-body so it will be pleased on that account. What is more, as Adam’s brain is now in the Brian-body and will therefore have Adam’s memories, the Brian-body will remember asking that the Brian-body should be given the money, and will also be pleased that the experimenter acted in accordance with that choice.
The Adam-body: After the operation, the experimenter tortures the Adam-body so it will be unhappy on that account. What is more, as Brian’s brain is now in the Adam-body and will therefore have Brian’s memories, the Adam-body will remember asking that the Brian-body should be tortured, so will also be unhappy that the experimenter has not done what they requested.
So the thought is, the person in the Adam body thinks that the experimenter has gone against their choice, whilst the person in the Brian-body thinks that the experimenter has gone with their choice. As the experimenter went with Adam’s choice, that suggests the person in the Brian-body is Adam. And as the experimenter went against Brian’s choice, that suggests that the person in the Adam-body is Brian.
So when we think carefully about such a case, it looks as though such an operation will constitute a body-transplant, and that the identity of the person travels with the brain.
The “Second Presentation”
What Williams is keen to point out, though, is that if we describe the case differently, our intuitions may well point us in an entirely different direction.
For example, consider this:
• Suppose I tell you that I am going to torture you tomorrow. You would rightly be frightened and apprehensive about tomorrow.
• But now suppose I tell you that, by the time the torture takes place, you will have forgotten that I told you about it. That doesn’t seem to give you any less feeling to be scared and apprehensive. In fact, maybe even more reason to be scared as it will be completely unexpected.
• So now imagine I tell you that, by the time the torture happens, you won’t remember anything of your past life at all. This would be like imagining that you are involved in an accident after which you wake up both in serious pain and with amnesia. That would still be something to be perturbed about happening.
• So suppose I now tell you that, not only will you not have any memories of your past, but you will have different memories of somebody else’s past and that you this will happen as a result of large-scale brain surgery where your own brain will be removed and replaced by someone else’s. Should this make you feel any better? Not according to Williams. In amongst everything else you know you still know this – tomorrow you will be tortured and the fact that the torture will be preceded by brain surgery and various psychological derangements does not make that possibility seem any less concerning.
But notice now that what we have done is described the very same thing that Adam chose (and appeared to be right to choose) to happen to his original body in the previous case! We have just described a case in which your brain is removed from your skull and someone else’s brain put in your body. But presented like this, it doesn’t seem quite so appealing.
• “It is differently presented, of course, and in two notable respects; but when we look at these two differences of presentation, can we really convince ourselves that the second presentation is wrong or misleading, thus leaving the road open to the first version which at the time seemed so convincing? Surely not” (300-301).
And indeed Perry points out (in a wonderful passage) that there is a similarly alternative way to describe the Senator / Peter Pressher events:
• “You are a senator from your home state. One morning you wake up on the sofa, seeming to remember being Peter Pressher, a lobbyist for the ACA. A man emerges from a bedroom, who seems to remember being you. But subsequent tests – fingerprints, testimony of close friends, comparison of medical records, etc. – establishes, to your delight and his dismay, that you are a duly elected senator with delusions (which you keep quiet about) of having been a lobbyist, while he is a lobbyist with delusions of having been a senator. His situation is rather ironic. He willingly participated in a scheme where his brain (and so various of his psychological characteristics) were exchanged for your brain (and so various of your psychological characteristics). He seems to have thought that would somehow constitute a “body transfer,” and he would wind up in the Senate. (He was taught this by a philosophy professor in college, whom he is suing). What actually happened, of course, is that two people underwent radical changes in character and personality, and acquired delusive memories, as a result of brain surgery” (269-70).
The underlying thought here is the following. When scientists do scientific experiments, they have to set the experiment up very carefully so as to ensure that they are testing exactly what they want to test and not allow anything external to affect the results of the experiment. Effectively, what Williams is trying to get across is that the same applies to the philosopher’s use of thought experiments. If we are to use thought experiments in an appropriate fashion, we need to be very careful not to allow our assessment of certain scenarios to be manipulated or influenced by irrelevant features, such as (for example) the language used to outline the scenario.
And where thought experiments are used in personal identity, Williams suggests, we must be alive to the possibility that our reactions and responses to the thought experiments are being influenced by language in such a way that we cannot rely on our intuitions being a reliable guide to the truth.
So, if we think that the essence of a person lies in their memories and psychological characteristics, then perhaps what is important is not the whole body, but that small part of it that is the basis of psychological characteristics – the brain.
But consider the following modification to the body transplant scenario.
Let’s assume that you are undergoing a body transplant of the sort just described. Your brain has been taken out and is being prepared to be installed in the new body. However, on examining your brain, suppose that the neuroscientists spot that there is some weakness in the blood vessels which could be the cause of the headaches you had been suffering from, and could leave you open to strokes in later life.
So rather than put this imperfect brain back into its brand new body, the neuroscientists use a new technology – brain rejuvenation technology – to make an exact psychological duplicate of your brain. This new brain will be psychologically just like the original, just far less likely to suffer from headaches, dizziness and the like. They then install it in the new body.
Just as before, this body will wake up, remember having been you, remember your friends and family, and so on. If you had been the subject of an experiment as before, the body would be pleased to have chosen – prior to the operation – that this body should be given $100,000 and not tortured and so on.
So, for the same reasons as we gave in the original transplant case, we might think that the person who wakes up will be you, even though they have a different brain.
Teletransportation
If you’re worried by the fact that this person wakes up with both a different brain and an unfamiliar body, we can also set up a similar example in which you wake up in a familiar body too.
Imagine that the kind of “teletransporter” found in Star Trek really works, and can instantaneously “beam” an individual from one place in the universe to another.
• You enter a cubicle and press a button. A scanner reads and records the exact state of all of your cells and transmits that information by radio to another machine based, say, on Mars. While on Mars, a replica brain and body – based exactly on the blueprint sent across – is being created out of new matter, your original brain and body down on Earth is being deconstructed to provide the raw materials for future replications.
Now what happens from your point of view? Well, you walk into one of these machines, press a button and lose consciousness for a short while. Then you wake up – wearing the same clothes, hair done in the same way, and so on – on Mars. What a great way to travel!
And from the point of view of others, the person on Mars seems to be you too. You might remember that you had promised to phone your partner, or your parents when you arrive, to tell them that everything went OK. You will continue to recognise your friends and family, and so on.
And again, for the same reasons as we gave in the original transplant case, we might think that the person who wakes up on Mars will be you, even though they have a brain made out of different material.
If you’re inclined to stick to the claim that brain identity is required for personal identity, and to deny that the person with the reduplicated brain and the replica on Mars are really you, then you can do that.
But, as Gretchen points out, this is not the most stable of resting places as refusing to accept that these individuals are you looks to be in tension with some of the reasons for thinking that the person went with the brain in the first place.
The first concern is that, when we were looking at why we thought that the person goes with the brain, one of the arguments we used was the following:
What is crucial to us as a person is our psychological characteristics; psychological characteristics are based in structures in the brain, not the body; so what is crucial to being a person goes with the brain.
But of course, a reduplicated brain or a transported brain would carry our psychological characteristics just as much as the original brain would. So if that is not enough to say that the person goes with the reduplicated brain, then why should it make us think that the person goes with the brain in the first place?
The second concern is that, when we discussed the advantages of a theory based on psychological characteristics, we noted that, on such a view, we could know that we were the same person as we were before purely by dint of our introspective awareness of our own minds.
But if we say that brain identity is required for personal identity, then in as much as I have no access to whether my brain is one and the same brain as it was before, I have no access to whether I am the same person that I was before.
For example, imagine that the brain transplant has taken place and I am lying in bed (in my new body) recovering. Believing that all that has transpired is a brain transplant, I think how lucky I am to be alive in such a technological age, and of all the plans and projects that I had before which I am now in a position to complete.
But then the neuroscientists come in and tell me that my original brain had some serious problems and therefore they duplicated it and implanted the duplicate. Now, according to this theory, I was wrong – I didn’t survive the operation after all (or rather, I did – I was created by the operation. The poor guy who thought he would survive – my predecessor – didn’t survive however).
So brain identity as a theory of personal identity looks to face similar problems to the more general body theory – what is crucial can survive both changes in body and change in brain.
So what is important? Well, given what we have seen, we might think that what is important is psychological identity. If what is important about personal identity is psychological characteristics then, as the person who walks out of the scanner on Mars is both psychologically and physically identical (in the qualitative sense) to me, then that person is indeed me.
But as soon as you stop tying the identity of the person to the identity of some particular lump of matter (body, brain or even soul) you open yourself up to a different range of problems.
Multiplication Of Psychological Duplicates
For example, the kinds of theoretical technologies we appealed to to show that brain identity is not necessary – brain reduplication and teletransporters – are both consistent with the possibility ofmore than one replicated person being produced. Indeed, this whas been the plot of a couple of Star Trek episodes.
To see this, imagine we have a network of teletransporters across the solar system. When you walk into the booth on Earth and push the button for Mars, something goes wrong and it sends your information to both Mars and Venus where new yous are created.
But now where are you?
Mars AND Venus?: Perhaps both of these people are you. But the problem with this is that, if M = E (Mars-you is identical with Earth-you) and V = E (Venus-you is identical with Earth-you), then it ought to be the case that V = M. But the person on Mars and the person on Venus are notidentical – after all, they could even talk to one another. So they can’t both one and the same person as you.
Mars OR Venus?:Perhaps only one of the two Replicas is you – either the one on Mars or the one on Venus. But they both have the same psychological characteristics (yours) and they both remember being you, and so on. So on what grounds could you say that Mars-you is the same person as you, but Venus-you is just somebody similar (or vice-versa)? What could possibly justify one choice over another?
Nowhere?: So perhaps you might think, because there are two of them, neither of them could be you. But think about the person on Mars – the question of whether he is you now depends, not on his psychological characteristics or his memories, but on a lack of competition! But that would be an odd thing for a claim of personal identity to stand or fall on.
So none of these options looks at all appealing!
Another problematic possibility is outlined by Parfit.
As before you walk into the scanner cubicle and press the button. But this time you don’t lose consciousness – in fact, nothing seems to happen at all.
So you walk out and tell the technicians that it isn’t working. Yes it is, they tell you – the scanner, data-collector, transmitter and reassembler on Mars are all working perfectly well. What is not the same as before is that, rather than destroying your old body immediately, the new scanner seriously damages your heart so that you die of heart failure a few hours later.
But, they tell you, don’t worry, because a new you is being reassembled on Mars as we speak, so as far as that person is concerned, everything is as normal. Maybe you even talk to this person – and he tells you not to worry, that he cares as much about your family as you do, and that he will look after them just as you would have, and so on.
However as Parfit says:
• “Since I can talk to my replica, it seems clear that he is not me. Though he is exactly like me, he is one person and I am another. When I pinch myself, he feels nothing. When I have my heart attack, he will again feel nothing. And when I am dead he will live for another forty years”.
But if the replicated person is not you in this case, then is he really you in the original case or, as he looks to be in this case, someone just like you after all? Here’s how Captain Picard resolved the issue…
Identity of Psychological Characteristics
A further problem is that, over time we are not psychologically identical with what we think of as our past selves.
For example, the me of right now is very psychologically different from the me of ten years ago, and I even have a few different memories from the me of this time yesterday – memories of some of the events which happened between now and then for example.
So our psychological characteristics are not identical across time, but are gradually changing, just like our physical characteristics are gradually changing (in that cells are steadily replaced and so on). But unlike the physical case, there appears to be no independent criteria (like space-time continuity) on which to ground psychological identity.
If this is the case, then what we think of as one and the same person, can change in psychological characteristics over time. So psychological identity cannot be necessary for personal identity either.
So where are we?
Well, when we considered the brain transplant case, it seemed that the “essence” of a person lies in their psychological, rather than their physical, characteristics.
This gave us some reason, but not necessarily a completely compelling reason, to think that bodily identity is not necessary for personal identity.
But then, as these were cases in which the brain was moved from body to body, we might think that brain identity is necessary for personal identity.
Then we looked at the reduplication / replication cases which give ways in which psychological characteristics could be transferred from body to body without requiring an identical brain. If these cases are coherent (i.e. possible in principle if not in practice) then they suggest that, if it is memory and psychological characteristics which are important, then brain identity is not necessary for personal identity either.
So we might think instead that what is necessary for personal identity is psychological identity, where by psychological identity, we mean that someone has exactly the same psychological characteristics.
However, as we saw, even this faces a number of problems:
First, it faces the difficulty that reduplication / replication cases give cases in which more than one individual might be produced who is psychologically identical with you (and indeed, with one another). But as these new individuals are physically distinct, they are not one and the same person, so it starts to look difficult to say that they could be the same person as you.
Second, by altering the way the teletransporter works such that the original body is not destroyed, we can give a case which suggests quite strongly that the person on Mars is not you, even though he or she shares your psychological characteristics.
Thirdly, there is the further problem that, over time we are not psychologically identical with what we think of as our past selves.
These considerations might push us back into thinking that physical identity is the key to personal identity after all, but there is another option which retains the centrality of our psychological characteristics to our personhood.
Psychological Continuity Theory
Psychological Continuity is the heart of Parfit’s approach to the issues surrounding personal identity. As you can see from the video above, Parfit accepts that, in Branch Line cases, the original person ceases to exist. However, he thinks that we shouldn’t be overly concerned by this.
The key to why he thinks this lies in his final statement: “my relation to each of them [the people at the end of the branch lines] would contain everything that matters”.
To get clearer on this, we will need to start by defining some terms.
The first thing to note is that, even if I am not psychologically identical with myself over time, two close time-slices of myself will be psychologically very similar. I will usually have very similar memories, beliefs, plans, projects and so on as I did five minutes ago.
In particular, from one moment to the next I will usually, for example, be able to remember what I have just done, and so on. Call this kind of relationship a relationship of strong psychological connectedness. Any two close time-slices of myself will usually be related by a number of links of strong psychological connectedness.
Now think about 100 time-slices of a person P1 – P100. So long as P1 is strongly psychologically connected to P2, P2 is strongly psychologically connected to P3, P3 to P4 and so on up to P100, we can say that P1 and P100 are psychologically continuous, even though they may not be strongly psychologically connected any more.
So even though I am not psychologically identical with the seven year-old version of myself – I no longer want to be a fireman for example – I am still psychologically continuous with him, because at each point between him and me, there are bonds of strong psychological connectedness.
With this in mind, let’s assume that, if you teletransported yourself and nothing went wrong, you would survive up on Mars because there is someone there who is strongly psychologically connected to you. Don’t worry about whether this person would be identical to you – just concentrate on this claim: that you would survive. Now with this in mind, think about the duplicatingtransporter case again and think about this:
If we don’t worry about whether one or both of the replicated individuals is identical to you, then it seems clear that you would also survive in the duplicating case – it’s just that, whereas before you survived in one person, now you survive in two!
What is required for personal survival, Parfit suggests, is not psychological identity but the right kinds of psychological continuity.
So long as there is at least one person somewhere, out there in the future that is psychologically continuous with you, that is all that is required for you to still survive in the future.
And in those boring normal cases in which there is only one person out there in the future that is psychologically continuous with you, then we might say that this person is identical with you. But don’t let this confuse you – there being someone “identical” to you (in this sense) out there in the future, is not what is needed for your personal survival. What is required is that there is someone psychologically continuous with you in the future – having someone identical to you out there is one way of this happening, but it is not the only way.
So even if there are two (or more) people out there in the future who are psychologically continuous with you, then even though you cannot be identical with them both, you can still survive in them both – their future existence is all that is required for your personal survival.
With this in mind, think about the teletransportation without destruction possibility. Up until the point of branching – the point at which an individual presses that button – there is at least one person out there in the future who is both psychologically continuous with that individual (and with a normal lifespan). So until the button is pressed, all the requirements for that individual’s personal survival are met.
As soon as the button is pressed, however, the individual back on Earth is no longer at a point before branching takes place, but post-branching. This means that, for this individual, there is no one out there in the future (for more than a couple of days at least) who is psychologically continuous with them. This is why the existence of someone very like you up on Mars doesn’t feel like survival for the you who is left on Earth.