To: Michael W.
From: Geoffrey Klempner
Subject: Identity and the mind-body problem
Date: 11 January 2002 14:49

Dear Mike,

Thank you for your e-mail of 28.12.01 with your essay for the Philosophy of Mind program in response to the question, 'Whereas one could trace a path from the Morning Star to the Evening Star, or from the North side of Everest to the South side, there is no path one could trace from the inside of the mind to the outside.' - Discuss.

You have made some interesting points in your essay, although you have not in fact understood the question in the way that I had intended. (Don't worry, this is a pretty common occurrence.)

Let me first explain what I did mean. The examples of the Morning Star and the Evening Star, and the South and North sides of Everest give the clue to the kind of 'tracing a path' in question. (The issue is discussed in unit 4, para 81 ff.)

The Morning Star does not exercise any causal effects on the Evening Star. (I was going to say, nor does the North side of Everest exercise any causal effects on the South side, but that is not quite as good an example because in the case of Everest we are talking about different 'parts' of an object, and the parts of an object exercise forces of gravitational attraction on one another.) What we term the 'Morning Star' is in fact a certain astronomical object (the planet Venus) seen from a particular point of view. What we term the 'Evening Star' is in fact the very same astronomical object seen from a different point of view. (I have subsequently learned that astronomers also talk collectively of 'morning stars' and 'evening stars', without the definite article.)

This example conveys an important logical point about identity statements: that they can sometimes convey factual information. In the case of Venus, as a result of careful astronomical observation it was concluded that *if* you could keep the Morning Star constantly in view until the evening (e.g. by leaving the surface of the Earth, then returning) you would find yourself looking at the Evening Star. This is what I mean by 'tracing a path'. The path in question is a conceptual construction, based on our primitive understanding of what it is to be one and the same object at a given time. (Namely, the same object is the same object, regardless of the direction from which you approach it, or the impact it makes on your experience.)

Now, what certain identity theorists want to say about mental and physical events (let's keep to events to avoid worries about the continuity of mental or physical 'objects') is that a mental event can be one and the same entity as a physical event. The difference is merely one of point of view. We see the mental event from the 'inside', by looking in our own minds, whereas we see the physical event from the 'outside', by noting its effects on measuring instruments.

The objection to this is that this does not distinguish between identity and mere 1-1 correlation. It is not possible to make the distinction in this case because there is no conceptual 'path' that can be traced, only a relation of cause and effect, mental event A is always correlated with physical event B.

OK, let's forget the essay title. I will take some of the blame in not making the question clearer.

You do say some important things about identity. Physical things are not constant, but acquire new parts and lose other parts, whether they be cars or people. Similarly, seen from the psychological point of view, a person is constantly changing, losing certain characteristics and acquiring others.

What some (not all) philosophers of language would say is that this is perfectly consistent with talk of identity. Identity over time involves 'tracing a path' under a concept that describes things of a particular sort, such as a car or a man. So the old Ford Capri with new differential, brakes, clutch etc. is the same car. GK at 50 is the same person as GK at 20. In the case of a person, there is physical as well as mental change.

It is true, however, that we fail to appreciate the hidden complexity underlying the notion of being 'one and the same person'.

One important point that you make, in regard to the mind-body question, is that it is not at all likely that we will in fact ever identify mental and physical events of types A and B as described above. For we are dealing with two wholly different levels of description. For the sake of argument, I am saying, suppose we were able to identify events that could figure either side of a mental-physical identity statement: what would follow? (the answer is, Nothing, because we can't distinguish between identity and 1-1 correlation). You are saying that in view of the complexity of the physical and mental systems that constitute a given individual, we cannot realistically hope to identify one unique element from each system to figure in an identity statement. I am inclined to agree!

The last point you make is that there is no clear dividing line between 'possession of a mind' and 'non-possession of a mind' as you would expect if there were such a thing as a mental substance. This hurts the Cartesian dualist more than it hurts the dualist who rejects the soul and merely claims that mental events are non-identical with physical events. However, even the Cartesian dualist has got to admit that our minds are in different states of alertness at different times - it can hardly have escaped their attention that an adult person not suffering from brain damage or dementia can sometimes be groggy or dopey.

All the best,

Geoffrey