To: Jeffrey D.
From: Geoffrey Klempner
Subject: Is personal identity dispensable? / ethics and sociobiology
Date: 8th May 2008 12:06

Dear Jeffrey,

Thank you for your two emails of 25 April, with your notes on unit 7 of Possible World Machine, and your second essay, entitled, 'Just who am I?', in response to the question, ''What thought experiments concerning body-duplication show is that the concept of personal IDENTITY is ultimately dispensable.' - Discuss.'

Identity

The first question to ask is why we need a notion of identity, in the sense of 'one and the same' or an 'individual', by contrast with identity of attributes. Philosophers sometimes use the term 'token identity' for individuals, by contrast with 'type identity' for attributes.

You state, correctly, that token identity depends upon spatio-temporal position. We track the identity of an individual by tracing its journey through space and time. So far so good.

This doesn't always work, however, because some physical individuals like an amoeba are capable of fission, the resulting two amoebae each satisfy the condition of 'spatio-temporal continuity' with the original amoeba. This straightaway leads to a contradiction with the law of identity, because A (the original amoeba) IS B (the amoeba on the left) and also IS C (the amoeba on the right) but B IS NOT C.

We're not too troubled by this. It's a case of 'say what you like.' Say that an amoeba only 'survives' so long as it doesn't undergo fission. At the moment when fission is complete, the original amoeba no longer exists.

Or, you could define an 'amoeba life history' as the branch of a tree going back to the original amoeba which spawned the countless amoebae. Each one of the resulting amoebae can be identified as a unique life history, even though all the life histories overlap at some point.

This is more or less the choice that faces us if we consider the logical possibility that human beings might divide like amoebae, each resulting individual carrying all the thoughts, memories, feelings and physical characteristics of the individual before the split. Neither of the alternatives is particularly palatable.

Imagine that you face the prospect that this will happen to you. Do you expect to die? Do you expect to survive? In what way?

This is the point where one's Cartesian intuitions come to the fore. I am tempted to say that I, the essential I, cannot be tied to what happens to my body. My identity cannot be monkeyed around with. Maybe I will die. But if I don't, then either I am the one on the left or I am the one on the right.

The problem with this response is that the 'soul substance' which I intend to refer to when I say 'I' has now been cut loose from all physical constraints. It does not occupy a spatial location (if you think it does, like spiritualist's ectoplasm, then we can simply duplicate the splitting scenario). But if soul substance is not spatially located then we have deprived it of the one thing which is capable of distinguishing token identity from type identity.

How can Descartes be confident that he has only one soul? Maybe he has a hundred identical souls. Or maybe his soul 'dies' every second and is replaced by a fresh soul. The fact that we can engage in these speculations shows that *no sense* has been given to the notion of being 'one and the same soul', there is no way to distinguish token identity from type identity for souls.

Natural laws and social laws

Your essay made me think of 'sociobiological' theories of morality. It is not clear from what you have written whether you would approve of this idea. Sociobiologists argue that the objective validity of social laws is a direct measure of their utility in promoting survival -- whether of the individual or of society.

Richard Dawkins in 'The Selfish Gene' explores arguments over whether, or in what sense, a natural 'social law' might develop through Darwinian evolution.

Dawkins dismisses the idea of applying the theory of evolution to societies (along the lines of, the fittest societies survive) because the mechanics of evolution depend on genes, and only genes. Dawkins reports experiments conducted with computer simulations, showing that a gene for altruism cannot survive because the altruists in any society will always be taken advantage of. However, a gene for 'I'll be nice to you if you are nice to me' has a better chance of survival than one which leads to purely selfish behaviour.

So far, so good. The problem is that morality demands a lot more than this.

However, we can also speculate on whether there might be a cultural equivalent of genes. Dawkins calls these 'memes'. Ideas that work, that benefit or stimulate human beings in such a way that those human beings are prompted to propagate those ideas survive and flourish, while other ideas appear for a moment and then are gone.

Is social morality such an idea? You teach your children to be moral, not lie or steal, and the resulting individuals have a better chance of teaching this to their children.

I liked your application of the idea of probability, which is not something which is often talked about. If you make the laws too strict then you are guaranteeing that they will be disobeyed. If they are too lenient then they become ineffective. So, from the point of view of memetics, social morality will be sufficiently demanding to make it more probable than not that a given individual will obey them (you can slide the probability scale from 50 per cent upwards as desired until you reach the optimal point).

In these terms, I would argue that in addition to natural laws and social laws there are rational laws, laws of reason. That is what ethics is about. As the unit on ethics shows, however, it is no easy task to make the case for reason.

Consider the 'Predator' films. Might Predator society be sufficiently different from ours so that 'morality' as we would understand the term has no place? What would such a society be like? How would it survive? The question here is not one that you can answer a priori. We can't be certain that such a society could not exist. Maybe they would find a way, a creative solution diametrically opposed to ours.

Is there something we have seen that Predators have missed? If you feel any urge to say 'yes' then that shows you are not fully convinced of the evolutionary argument as a full account of the nature of what it is to be 'moral'.

All the best,

Geoffrey