Monday, July 23, 2012

Locke's account of persons and their identity

To: Scott B.
From: Geoffrey Klempner
Subject: Locke's account of persons and their identity
Date: 23 January 2008 13:05

Dear Scott,

These are my comments on your University of London Introduction to Philosophy essay, in response to the question, 'Outline and evaluate Locke's account of persons and their identity.'

You have given a very full and careful exposition of Locke's account of personal identity, which takes into consideration Locke's view about the identity for different kinds of material body.

The interesting point, which you successfully bring out, is that the conditions for the identity of a living body are functional, in terms of continuity of organism, allowing for the possibility of significant change over time without loss of identity. While the conditions for the identity of a person are defined in terms of memory and continuity of consciousness.

In principle, as Locke's thought experiments show, these criteria could give divergent results, when, e.g. by some mysterious process the consciousnesses of a prince and a pauper are exchanged. A significant point here is that the identity of the soul, as defined as a non-physical entity, has no part to play. We may suppose that the souls of the prince and the pauper are exchanged with no corresponding change in memory/ consciousness, or that memory and consciousness are exchanged while each soul remains in the body to which it was originally assigned.

This is, in effect, a devastating critique of the notion of a soul, which shows that as a metaphysical entity it has no function or purpose. Further proof that souls do not, or cannot exist is not needed.

This answers half the question.

The other half of the question concerns the evaluation of Locke's account of personal identity.

Locke claimed that his theory was 'forensic', in the sense of being determined by the point of the concept of a person, as an individual whom we hold accountable for his/her deeds, whether good or bad. Holding someone to account presupposes that they are aware of what they have done.

There is, however, a serious problem in principle with the way Locke separates the identity of an individual qua organism and the identity of a person in terms of consciousness/ memory.

This problem is illustrated, e.g., by claims that persons can be hypnotised into 'recalling' their past lives. Let's say that as a result of undergoing hypnosis you become convinced that in your past life you were a mass murderer. Wracked with guilt, you surrender yourself to the police explaining the circumstances in which you discovered your 'true' identity.

The Police would be naturally sceptical, but there are questions which they might put to you in order to 'confirm' your story. Let's say you 'remember' where one of the bodies is buried, and, true enough the body is found just where you said. And so on.

This is evidence for a remarkable parapsychological gift of knowing what the murderer did; it is not, and cannot be evidence that you are the murderer.

In short, what is missing from Locke's account is a way of distinguishing between veridical and non-veridical memory. Veridical memory that 'I buried the body in location X' entails not only that the body is in location X, but that *I* was the one who buried it there.

What would be sufficient to show this would be evidence of the continuity of the *causal source* of continuity of consciousness/ memory. For example, you were not born but grown in a vat, and given the transplanted brain of the murderer.

This is by no means a solution to the vexed problem of defining personal identity. What it shows is that a purely psychological criterion cannot be defended. However, there are those who defend a modified version of Locke's account, as outlined above.

There is a remaining difficulty, pointed to by your initial remarks about the notion of identity not being capable of being many-one or one-many.

Sydney Shoemaker originally put forward the thought experiment of a man whose brain is split in two, with each half given to a different recipient. Each of the recipients is firmly convinced that he is the original owner of the brain. Continuity of all that is necessary and sufficient for continuity of consciousness/ memory does not require identity.

Today, we are familiar with the idea that the same 'program' can be uploaded into any number of devices capable of running that program. If the 'function' of the human brain is correctly described in terms of running a program, as AI theorists believe, then the possibility would arise of an unlimited number of 'me's, each satisfying the modified Lockean account.

All the best,

Geoffrey