Continuity of Consciousness

PHIL 131 – Mind and World

Research Essay

Explain Locke’s view that personal identity depends on continuity of consciousness, rather than continuity of substance. How does he argue for his view over the alternatives he considers? What do you think are the strongest objections to Locke’s view? Give your own evaluation of the success of Locke’s argument and defend your answer with reasons.

The question of personal identity, that is, the question of what ensures that a person is that person over time, is one that has been debated in philosophy for centuries. One of the first people to explore this question was John Locke, as part of his work An Essay on Human Understanding.  Defining personal identity in terms of the way thinking, intelligent beings are able to chart the sameness of their self over time, the question Locke is seeking to answer becomes ‘what makes the same person think themselves that person over time’?^[1] He considers three possible answers to this question of continuity of the self: the physical body; the possible immortal soul; and the consciousness.

Locke immediately answers his question by saying that consciousness, which Locke sees as inseparable from thought,^[2] is the root of personal identity. Locke goes on to further define consciousness as memory, saying that the only way to determine if a person is the same person over time is if they are conscious of the actions they previously performed and the thoughts they had at the time.^[3] With these definitions, Locke explores some of the moral complications of his view, saying that it should be taken as a given that it is impossible to assign blame for the thoughts and actions of a person when that person is not conscious of those thoughts and actions. Thus, Locke says “to punish Socrates waking for what sleeping Socrates thought, and waking Socrates was never conscious of, would be no more right, than to punish one twin for what his brother-twin did.”^[4] Locke explores this from the point of view of mental illness, stating that in events where a person can exist in two separate states, madness and sobriety, and there is no consciousness shared between the two states, then no humane law will punish the mad person for the actions performed while sober, or punish the sober person for the actions performed while mad^[5], since in the cases such as this, we refer to such people as not being themselves, proving the change in personal identity between the two states of consciousness.^[6]

Having established his position, Locke continues on to examine the other possible answers to his question. Considering the body, Locke accepts that people may see the body as an important part of themselves, but rejects the idea that the physical self can be a meaningful marker of the sameness over a person over time.^[7] Using the example of a man losing a hand, Locke establishes that the man does not change into a new identity because of the physical change, and the hand does not constitute a separated part of the identity that once used the hand.^[8] Locke goes on to discuss this from the perspective of a finger that has been removed from a person, saying that “should this consciousness go along with the little Finger, and leave the rest of the Body, ‘tis evident the little Finger would be the person.”^[9] He does point out that this, however, ensures the primacy of consciousness as the marker of personal identity.^[10] For Locke, since the body can change significantly over a person’s lifetime without another identity arising, and parts of the body can be removed without any proof of the self being attached to it afterwards; the body cannot be the marker of personal identity.

In his consideration of the possibility that a soul could be the marker of personal identity over time, Locke rejects the idea using two examples. The first example Locke brings up is the concept of reincarnation, where one eternal soul has occupied multiple bodies and multiple selves over the course of human history. Going on to speak of an acquaintance that believed that his soul had once been the soul of Socrates, Locke asserts that no one would say that both his acquaintance and Socrates are the same person, even if his claims were true, since the man has no demonstrable memory of being Socrates.^[11] Locke goes on to say that if someone did possess the soul of a historical figure, without conscious memory of that figures thoughts and actions it would be no different to having the same atoms present in part of their physical makeup, but if those memories were present, then that person and the historical figure can be considered to be the same person.^[12] Locke makes a further point about possibility of a soul changing between living bodies, and uses this to further re-enforce his point that, unless the consciousness of the original person is also transferred, then no-one would be able to say that the soul’s new body was the original person.^[13]

Of the multiple objections to Locke’s view that continuity of consciousness, as defined by the ability to remember events of the past, those objections that highlight the unreliability of memory stand out. Thomas Reid uses the example of the Brave Officer – an old general remembers his actions in war as an officer, but not the flogging he received at school as a boy – to show that Locke’s argument results in a logical contradiction where the general both was and was not punished as a boy.^[14]. According to Reid, since the general remembers being the officer who fought in war, and the officer remembered being the boy, the general is and should be the same person as the boy. According to Locke, however, since the general’s consciousness doesn’t reach back as far as the boy’s flogging, they cannot be considered the same person. Locke does address this objection by creating a difference of definition between ‘same person’ and ‘same human being’, stating that “if it be possible for the same man to have distinct incommunicable consciousness at different times, it is past doubt that the same man would at different times make different persons.”^[15] Simon Blackburn, in his recounting and analysis of both Locke’s and Reid’s views, suggests that both men may have been approaching the question from different starting positions, with Locke viewing a person as a complex entity capable of cumulative change resulting from smaller changes, while Reid saw humans as simpler beings that are essentially incapable of this method of change.^[16]

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