To: Hakeem G.
From: Geoffrey Klempner
Subject: Locke on the identity of 'person' and 'human being'
Date: 23 April 2007 11:51

Dear Hakeem,

Thank you for your email of 17 April, with your University of London Essay in response to the question, 'According to Locke, how does the identity of a person differ from the identity of a human being? What does he think the identity of a person requires?'

This is a rather long essay (at over 4000 words compared to the target length of 2500) and at times I had the impression that I was reading a report on the reading that you had done on this topic.

I have no doubt that you did a lot of work on this question, and you will probably not welcome my suggestion that you should have done more! However, it is also necessary to bear in mind how you are going to respond if a question like this comes up in the exam. Will you have the arguments at your fingertips? Will you know how to respond to the particular wording of the question?

You do raise a number of important issues, in particular Locke's idea of identity over time as necessarily identity under a particular sortal concept. Thus arises the possibility that one and the same living being is not the same collection of material parts, and, crucially for Locke, one and the same person is not necessarily the same living being.

This idea of 'identity under a sortal concept' has in recent times been developed by David Wiggins, first in his monograph 'Identity and Spatio-Temporal Continuity' and later in his longer book, 'Sameness and substance'. Wiggins is not defending the view of 'relative identity'. where A can be the same f as B but not the same g as B, a view associated with the logician Peter Geach. (Wiggins' argument is that if A=B then there is no way in which it could fail to be the case that A=B. If we say that A is the same f as B but not the same g as B, then the term 'B' must necessarily be referring to two different individuals. Hence, this is not, as first appears, a case of relative identity.)

Wiggins is heavily dependent on Aristotle's view of essence, and fully admits that his theory is in effect the Aristotelian view brought up to date.

Another important issue which you raise is the problem that continuity of consciousness can allow for the possibility that the change from A to B and B to C both satisfy the conditions for 'same consciousness' even though A has nothing in common with C. This is a line of criticism developed by Derek Parfit in his book 'Reasons and Persons' where he puts forward the controversial theory that personal identity cannot be adequately 'defined' and is not as 'important' as we take it to be.

It is necessary to ask why Locke defines personal identity in the way that he does, the motivation that he gives for his definition. You do briefly mention the fact that we 'hold persons accountable'. However, for Locke this is not just incidental but central to his theory. Personal identity is, in Locke's words, a 'forensic' notion. Our interest in personal identity is based on our interest in the criticism and evaluation of one another's actions.

It is here that the most serious problem for Locke's account arises. Having distinguished between the notions of 'same mass', 'same life' and 'same person', Locke offers an account of memory which fails to account for the difference between 'true' and 'false' memories. This is a point made by Wiggins in 'Sameness and Substance'.

Suppose that I wake up tomorrow morning 'remembering' that I was once Socrates, and recalling a conversation that I had in the market square in Athens with my pupil Plato. The question would arise what is it in virtue of which my claim is true or false? Not the claim that the events took place as described, but rather the claim that *I* was there as Socrates. It is not sufficient that memory correspond to events that actually occurred; in addition, we require a causal link -- or, rather, the right kind of causal link -- consisting of a sequence of states forming a causal chain in which memory is transmitted and preserved. If we give up the requirement of continuity of matter, or at least something that is capable of preserving the causal chain, then it becomes in principle impossible to distinguish genuine causality from accidental correspondence. In order to 'be' Socrates resurrected, there must be some story which can be told, in principle about how GK's memories are caused by the events which I seem to recall taking place in the market square.

On Locke's view, if someone appeared who seemed to possess the memories of a serial murderer, then we would be obliged to punish that person for the murderer's crimes. Yet, arguably, punishment is only justified if that person really is the murderer -- the person who actually did those crimes -- and not merely someone who has qualitatively the 'same' conscious states as the murderer.

What prevented Locke from appreciating this point is his implicit adherence to Cartesian dualism, even though he strongly downplays the role of any notion of a 'soul' on the grounds that it fails to designate anything that we meet up with in our experience. The claim that memory is essentially causal, requiring the persistence of matter, can only be realized on the assumption of materialism.

All the best,

Geoffrey