Shortly after the announcement that British scientists had successfully cloned a sheep, The Guardian ran an article about a man who thought that cloning could provide a route to immortality The article did not include a detailed account of how this was to be achieved, but the essential idea is that since in cloning the genetic blueprint for a particular individual is used to make another individual with the same genetic makeup, the new individual will be an exact copy of the original, and an exact copy is as good as the original.
Thus, the suggestion is that we can bring back the dead by cloning them. All we need is a few cells removed from the body just before death, and we can use these to produce a person with the same genetic makeup, so, in a way, recreating the dead person. In this way, if I can have myself cloned, I can make sure that after my death there will be someone with the same genetic makeup as myself, who will be an exact copy of me. Having this exact copy made is the same as being resurrected, which, if the process is continued, will give me immortality.
An alternative way of achieving immortality through cloning is the rather grisly one using a clones as a source of spare parts. Well before my eyes start to fade, and my heart starts to falter, I have a clone of myself produced. When this clone is, say, seventeen, I have his eyes and heart transplanted into me. This transplant will probably be successful, since there is less likelihood of the transplanted parts being rejected, because they are genetically identical to my own heart and eyes. Similarly if I keep having clones produced, there will spares for any bit of me that wears out. Thus, I will be able to live for ever. (We may be able to get the spare parts by a different sort of cloning, in which bits of my tissue are cultivated into spare organs in tanks. This might be preferable to chopping up a seventeen year old boy for parts.)
The question is, do either of these suggestions actually provide the sort of immortality we usually want? To answer this question, we must decide what we want from immortality. Now it is possible that different people want different things, so I will have to answer for myself, but I suspect that in this, at least, I am not much different from most people. I do not just want my body to last (in good condition) forever, or my name to be honoured for all time. The most important part of wanting to live forever is, for me at least, wanting to experience the future of that immortal life in the same direct way that I experience the present.
The way I have my experiences now is as part of the present stream of consciousness. To have future experiences in the same way, those future experiences must be part of the same stream. That is, the present stream must continue and eventually include those experiences, so that the experiences I am having now will overlap with further experiences in a chain of overlapping experiences that ultimately includes the future experiences. In short, what I want is the infinite continuation of my stream of consciousness, the stream of consciousness of which my present experience is part. This continuity is a necessary condition for my survival. Without it, I do not survive.
An obvious objection here is to say that my stream of consciousness is interrupted every time I go to sleep, and yet I believe that I have survived that interruption. If the continuity of my stream of consciousness really is a necessary condition of my survival, I would have to admit that I will not survive tonight’s sleep. In reply, I will first point out that I believe (as did Descartes) that in fact the stream of consciousness continues during sleep, even if we do not always remember it. This view is supported by the results of psychological experiments on sleep, including studies in which people woken from various stages of sleep were able to report what they had been thinking while asleep, but I will not discuss it in detail here. Second, even if the stream of consciousness does not continue during sleep, there certainly seems to be some sort of strong continuity between the me who went to sleep and the me who wakes up to the extent that my present stream of consciousness seems to be a continuation of the stream of consciousness I had yesterday. Thus, I can amend my claim to say that what I want is the infinite continuation of my stream of consciousness, or, if there are any interruptions in my stream of consciousness, there must be at least the same sort of continuity as that between going to sleep and waking up, whatever that continuity might consist in. If I can arrange that infinite continuation of my stream of consciousness, I will have the most important part of immortality. I will survive forever.
Can I get this by having a clone of myself made? If my stream of consciousness ceases when I die, and a stream of consciousness starts when the clone is produced, will my stream of consciousness be continuous with his? I cannot see how it could be. The clone’s stream of consciousness will develop with the clone, but have no connection with mine. Thus, the stream of consciousness of the clone is not the continuation of my stream of consciousness. Now since I have established that worthwhile immortality requires the continuation of my stream of consciousness, simply creating a clone of me does not provide immortality. I have to find some way of transferring my stream of consciousness to the clone, and my stream of consciousness must either remain uninterrupted during the transfer or at least have the same sort of continuity as that between going to sleep and waking up.
It has been suggested that the continuity can be created by in some way recording all my my memories, ideas, personality traits, and thoughts and then putting all the information into the clone’s brain. This sort of recording was done with Lister in the television show Red Dwarf, and at first blush it seems convincing enough. After all, we are used to our memories, ideas, etc., always accompanying our stream of consciousness, and so we usually think that they will stay together. Where one goes, there the rest will go. But it is not necessarily so. Here is an imaginary case to try to demonstrate this. (This example is adapted from Unger, 1986, and Knox, 1969.)
(Part 1) I collapse onto the floor. Then I find that I seem to be floating up out of my body and hovering near the ceiling, looking down on my body, as in the standard accounts of out-of-body experience. The body on the floor begins to move. It gets up and acts, talks, and shows that consciousness is again associated with the body. There are two conscious beings. One is me, floating near the ceiling, and the other is the being with the body that used to be mine.
(Part 2) While floating away from the body I suddenly lose my personal memory (memory of my past life, as distinct from memory of the English language) and my personality changes. The being in what used to be my body appears to have memories qualitatively similar to the memories I had, and a personality qualitatively similar to the personality I had.
In part 1, I consider my survival to be independent of my body. I survive as the floating being, not the one that inhabits the body I thought of as mine, because the stream of consciousness of the floating being is continuous with my stream of consciousness before I collapsed.
In part 2, the being in my body has physical continuity with the person I was, and has greater psychological continuity with the exception of the continuity of conscious experience. All my friends will think that I simply fainted. The conscious being acts like I used to and can remember the things I used to. Possibly even he thinks that he is a continuation of me. Yet in this case also I consider that I survive as the floating being, not the embodied one, because of the continuity of the stream of consciousness. If, before the collapse, I knew it was going to happen, and I also knew that after the collapse, the floating being would suffer the tortures of Hell, I would feel genuine fear, because I would expect to suffer the tortures of Hell in exactly the same direct way I am suffering the tortures of writing a philosophy paper now.
In other words, it seems that my memories, etc. can go one way, and my stream of consciousness can go another. If this is so, then when I am linked up to the device which transfers my memories, etc. to the clone, there is no guarantee that it will also transfer my stream of consciousness.
Also, there is an interruption between the end of my stream of consciousness and the start of the clone’s stream of consciousness, but there is no guarantee that the interruption will be bridged by the sort of continuity we have during sleep. We do not know what provides that continuity, so we cannot assume that the recording process would provide it. (In ordinary sleep my body and brain do not cease to exist and do not cease to function. It is quite reasonable to suggest that their continuity is the foundation for the continuity I feel between the me who went to sleep and the me who wakes up. If I die, my body and brain cease to function. Alternatively, if I am right and the stream of consciousness of a living person never ceases, even during sleep, then again the recording process will not provide the necessary continuity.)
Just producing a clone of me will not give me immortality. From this it follows, that if the clone does not provide a way for me to be recreated after my death, then of course it does not provide a way or recreating other dead people either. A clone of Mozart will have the same genetic makeup as Mozart, but it will not be Mozart.
However, there does seem to be a way I can use cloning to live forever, and that is by a special use of the cloned spare parts. There is no theoretical problem about replacing most parts, but when we come to the brain it is a different story. As my old brain wears out, I need to replace it with the new brain. The trouble is that, for the reasons outlined above, I have to transfer my stream of consciousness to the new brain, and it is not clear how I can do that. Still, there does seem to be a way around the problem. If I cannot transfer my stream of consciousness to the new brain, I can get the same result by transferring the new brain to my stream of consciousness. I need to find a way of taking out tiny bits of my old brain, and replacing them with tiny bits from the new brain, while I am conscious. Each tiny piece would have to be so small that its removal would not affect the continuity of my stream of consciousness. If we can do this, eventually all the old brain would be replaced by the new brain, without any interruption to my stream of consciousness.
Perhaps when the bits of my brain are being replaced, I will find that my personality changes, and perhaps some or all of my memories or skills are lost. This would be regrettable, but it is the sort of thing that happens anyway. As I get older at least some aspects of my personality change (usually for the worse) and some of my memories disappear. (Especially, but not solely, memories of what my wife told me to do this morning.) If the piecemeal brain replacement were similar, but I could still form new memories, regain skills or gain new ones, and form a personality no more inadequate than the one I have now, I would not object too strongly. Indeed, there are some memories I would be happier without.
This imaginary technique seems to be the most probable way that we can gain immortality from any sort of cloning, but it is a long way from anything that is possible at the moment. Indeed, even when the technique of transplanting bits of brain is perfected, it is still not clear that it will be possible. We may find, for example, that there is some bit of the brain that cannot be disconnected without interrupting the stream of consciousness. We have a long way to go from Dolly to immortality.