Is R2-D2 a person?
- Staying Alive: Personal Identity, Practical Concerns and the Unity of a Life by Marya Schechtman
Oxford, 214 pp, £35.00, March 2014, ISBN 978 0 19 968487 8
What does it take for a person in 2015 to be the same person as she was in 1995 and will be in 2035? This is the question of personal identity, a question about persistence through time, or ‘diachronic’ identity. It seems enough at first to say that the person is the same in 2015 as in 1995 and in 2035 just so long as she is the same living human animal, the same biological organism (same passport, same national insurance number, same DNA). This is enough for the passport office, HMRC and those philosophers of personal identity who are called ‘animalists’ (notably Paul Snowdon and Eric Olson). But the concept of a person contains pressures that push us to say different things. We have for example to consider diseases that radically alter personality. People have divorced on the grounds that ‘this isn’t the person I married,’ and one doesn’t need to be unwell to feel what Henry James felt, writing to Rhoda Broughton in November 1915 after she had praised one of (what he called) his ‘old perpetrations’: ‘I think of it, the masterpiece in question, as the work of quite another person than myself, at this date – that of a rich (so much rather than a poor) relation, say, who … suffers me still to claim a shy fourth cousinship.’ People regularly and sincerely claim to have become a different person although they know they’re the same biological organism as before. They think that it’s their mental being – in particular their overall personality – that’s essential to their always being the person they are.
If this is right, it looks as if the person that I am can survive when a surgical supercomputer transplants my brain into a perfect clone body (assuming, plausibly enough, that my fundamental mental being is carried in my brain), leaving my 1952-2015 body to be cremated or recycled. And it’s not even clear that I need a perfect clone body in order to survive. Locke in 1694 imagined the souls of a prince and a cobbler swapping bodies, and we can run the same thought experiment today substituting brains for souls. It seems natural to think that after the swap the cobbler has the prince’s body and vice versa. Suppose the prince had committed a murder before the swap: who (which body) should be locked up?
Things become less clear when we increase the differences between the two bodies. (Emily Dickinson in Winston Churchill’s body? Martin Amis in Joyce Carol Oates’s?) We can reduce the impact of a strange body by imagining that the overall chemistry of the transferred brain is essentially the same as in the old body (no strange hormonal rushes). Even so, there may be limits on how different one’s new body can be if one is to remain the same person. I may feel I’m most essentially a mental self, that my identity is in some deep way independent of my body, but ‘I am not merely present in my body as a sailor is present in a ship,’ as Descartes observed. ‘I am very closely joined and, as it were, intermingled with it, so that I and the body form a unit.’
Locke leaves our bodies unchanged in another famous thought experiment. He imagines the instantaneous transfer of our whole mental being (personality, memories and so on) from one immaterial soul or ‘soul-substance’ to another. Derek Parfit also preserves strong bodily similarity in his ‘teletransportation’ thought experiment, a variation on Locke in which a superscanner records every last detail of the structure of one’s body (including one’s brain) and encodes it in digital form, destroying the body in the process. The resulting data file is then radio-transmitted to Mars, allowing a perfect replica of one’s body to be assembled from new matter.
Parfitian teletransportation is not like being ‘beamed up’ by a ‘transporter’ in Star Trek – if (as most people suppose) beaming transmits the matter that makes up one’s body as ‘energy’ which is reassembled exactly as it was on arrival. On the journey to Mars one exists only as a complex pattern of radio waves. This, perhaps, is why many doubt they’d survive teletransportation even when they think they’d survive Star Trek beaming. But it’s hard on reflection to see why teletransportation would be less good than beaming. In everyday life the atoms constituting one’s brain (in particular one’s neurons) are constantly being replaced in processes of cell repair. It may be that one’s brain today has almost no matter in common with one’s brain six months ago. So why should it be fatal if the replacement happens much faster than usual, or even all at once? It seems that there’s something deeply right about the Lockean idea that a person is essentially just a certain kind of complex informational pattern, a pattern that must have some concrete incarnation in order to exist, but that can nonetheless persist through time without its usual vehicle, i.e. a living brain (or, if you will, an immaterial soul). Suppose it becomes routine for medical 3D printers to issue new disease-free clone bodies for the seriously ill. How long will the old view survive, that a person’s fate depends on the fate of the body they were born with?
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