man from those of a man’s personal identity. According to Locke, a person is ‘a thinking
intelligent Being, that has reason and reflection, and can consider it self as it self, the same
thinking thing in different times and places’ [2.27.9]. One might also want to include that
persons are necessarily subjects of perception and authors of intentional action i.e. they’re
both percipients and agents. In other words, a person isn’t simply a member of our species
since some human beings lack the power of reason and self-consciousness. Furthermore, in
principle, some non-human creatures could be considered persons. Locke recites a tale of
a rational parrot that was able to answer some quite detailed questions in a convincing way,
but he points out that we would be unlikely to call it a man, despite its intelligence. It would
always be a rational parrot, but it might also be considered a person if it had the appropriate
level of rationality and self-consciousness.
According to Locke, the criterion of personal identity over time is not simply bodily
continuity, since that does not guarantee us that we are dealing with the same person.
Rather, personal identity stretches only so far as consciousness will stretch: ‘as far as this
consciousness can be extended backwars to any past action or thought, so far reaches the
identity of that person’[Locke, 2.27.9]. No matter how much I’ve changed physically, if I
can remember my past actions as my own, then I am the same person that I was.
Locke illuminates this notion with a thought experiment. Imagine that one day a prince
wakes up to find that he has all the memories of a cobbler, and none of his own. His body
remains unchanged. On the same morning a cobbler wakes up to find that he has all the
prince’s memories. Locke maintains that, although the prince-bodied individual remains the
same man, he is not the same person that he was when he went to sleep. It would not be
fair to hold the prince-bodied person responsible for the prince’s former actions, since he
would not have any recollection of having performed them. This example is intended to
bring out the important difference between the terms ‘man’ and ‘person’.
It would seem that on Locke’s account we should never punish people for what they can’t
remember doing since they would not be the same persons who committed the acts.
‘Person’ for Locke is a term which is particularly relevant to legal questions which relate to
the responsibility of one’s actions. It would seem then that we should never punish a
murderer who can’t remember killing. Locke’s view on this is that in cases of memory loss
or alleged memory loss, we tend to assume that if we have identified the man who
performed the actions, then this must be the same person who committed them. We punish
drunks for their actions even if they claim not to be able to remember what they did.
However, this is simply a result of the difficulty of anyone proving their ignorance of what
they did. The law has to be practical and so rarely accepts memory loss as an excuse.
However, Locke suggests, on the day of judgement, God will not hold anyone responsible
for actions which they can’t remember performing.
The philosopher Thomas Reid countered Locke’s claim that memory provides an adequate
criterion of personal identity with the following example. Imagine a brave officer who was
once flogged at school for stealing from an orchard. In his first campaign as a young soldier
he succeeded in capturing a standard from the enemy. When he captured the standard he
could remember that he has been flogged as a boy. Later, he was made general. But by
that time, although he could remember capturing the standard, he could no longer remember
being flogged at school. The person who captured the standard is, on Locke’s account, the
same person who was flogged, because of the memory link. Similarly, the memory link
makes the general the same person as the young officer who captured the standard, but the
general is not the same person as the boy. However, the principle of transitivity of identity
tells us that if the boy is the same person as the young officer, and the officer the same
person as the general, then the boy must be the same person as the general. If X is the same
as Y, and Y is the same as Z, then X is the same as Z. Reid’s point is that Locke’s account
gives us two contradictory conclusions: both that the boy and the general are the same
person, and that they are not. Any theory which leads to such an obvious contradiction
must be false.
Locke’s response to this sort of criticism would have to be that the boy and the general are
the same man but not the same person, and that it would be wrong to hold the general
responsible for what the boy did. Locke could try to deny the principle of transitivity, but
this seems ludicrous.
In the face of this difficulty, Mackie argues that a Lockean might say that there are ‘units of
potential consciousness’. In principle, a person could remember every conscious
experience of his, even those that he cannot in fact be brought to remember by any stimulus.
The ‘could in principle’ surely means only those actions and experiences that are his. If this
suggestion is to avoid circularity, it must presuppose that there is some other criterion or
constituent of personal identity thereby tacitly abandoning Lockean theory.
Instead Mackie suggests that a more plausible defence would turn the problem of transitivity
into an advantage. One could argue that the general’s, the boy’s and the officer’s
experiences all belong to the same unified mental history. However, this is a revision of
Locke’s account, not an interpretation. Locke commits himself explicitly to the view that I
am not the same person as the one who has committed an act of which I now no longer
remember.
Another criticism of Locke also concerns the fallibility of memory but is the converse of the
first. Failure to remember is one thing, but misremembering is another. What, then, do we
say when a person claims to remember doing something which we know, on independent
grounds, he did not do? The example made famous by Bertrand Russell is that of George
IV who apparently ‘remembered’ leading his troops to victory at the battle of Waterloo, a
battle at which he wasn’t present. Surely he is not really that person?
Naturally one could reply that Locke could not have meant that just any claim to remember
would entail identity, surely he meant that only valid claims would do so. That is, it is only
when my remembering corresponds with the true state of affairs that it is a criterion of
identity. However, this would leave his position logically intact, but without a working
criterion of personal identity: it would be impossible for us to judge which memories are true
and which are not.
The third main criticism stems from the eighteenth-century philosopher Joseph Butler. His
contention was that consciousness of personal identity presupposes, and therefore cannot
constitute, personal identity. On Locke’s account, we can infer from the fact that I
remember doing X that I was the person that did X. According to Butler, this must be false
because the formulation of my memory claim already has built in to it the fact that I was the
person concerned. We tend to say ‘I remember doing X’, but this is just an abbreviated
version of ‘I remember that I was the person that was doing X’. His proposition is that the
memory claim contains within it an assertion of identity, and therefore it cannot be regarded
as an independent premise from which identity can be inferred. Consequently memory
cannot be the only criterion for personal identity.
What these criticisms of Locke’s theory of personal identity show is that we would have to
refine his thoughts to get near anything that was defendable. However this process might
leads us so far away from Locke’s account as to leave them incomparable.
BIBLIOGRAPHY
Chappell (ed) – Cambridge Companion To Locke
Locke – Essay On Human Understanding (edited by P. Nidditch) (Oxford University Press,
1975)
Lowe – Locke on Human Understanding (Routledge, 1995)
Mackie – Problems From Locke
Noonan – Personal Identity (Routledge, 1989)
Winkler – Locke On Personal Identity
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