In the chapter XXVII of the Essay Concerning Human Understanding, Locke reflects on what identity consists in. He starts with identity of substances which can be divided into three sorts: God, finite intelligences and bodies. God’s identity cannot be questionable as he is eternal, unalterable and everywhere. Identity of finite intelligences is defined by relation to time and place as each spirit has its determinate time and place of existence. As for bodies, their identity is determined by the organisation of particles of matter that is distinguished from all other bodies. The parts of an oak are organised as one coherent body partaking of one common life. They receive and distribute nourishment so that wood, bark and leaves continue to grow.  So, this collection of matter united to the living body of the plant is that identity which makes the same plant. Similarly to plants, identity of brutes and men is placed in a fitly organized body to a certain end.

For Locke, however, identity of man, thinking substance and person stand for three different ideas.  We can place the identity of man in the particles of matter united to the same organised body. While the word man applies to an idea of body, thinking substance applies to an idea of which body and shape are excluded. This is the idea of soul, which is of the opinion that it can be thrust into the bodies of beasts or into the bodies of different men living in distant ages. In this regard, Locke refutes the idea that two distinct persons can be of the same immaterial substance. As long as the soul has a remaining consciousness of what it did in the preexistent state, it defines the identity of the same person. Anyone who would persuade that his soul is that of Socrates could not be the same person with Socrates, since he is not conscious of any of Socrates’ actions or thoughts. Thus, consciousness makes personal identity that reaches no further than consciousness reaches. In other words, as far as this consciousness can be extended backwards to any past action or thought, so far as person can consider itself as itself, the same thinking thing in different times and places.

Further difficulty may arise if we try to reflect on our past selves. Our consciousness is being interrupted always by forgetfulness and we cannot have all our past actions before our eyes in one view. In this case, doubts are raised whether we are the same thinking substance or the same person. For Locke, it does not matter if it is the same identical substance which always thinks in the same person. Different substances can be varied and united into one person by the same consciousness. So, what matters is the same consciousness that makes a man be himself to himself, whatever substances that contributed to man’s actions. Even if the being cuts off a hand and separate if from the consciousness, there would not be a change of personal identity. The hand is no longer a part of that which is himself, but the rest of particles are vitally united to the same thinking conscious self. In case of forgetfulness of a being, it is reasonable to think that this being cannot be wholly stripped of all the consciousness of its past existence. The fact that the being has the power to retrieve the consciousness of past actions, even partly, shows that it is the same person.

However, imagine that a person wholly loses the memory of his past life beyond a possibility of retrieving it. Can we say that we are accountable for any actions in the past if we never be conscious of them again? Locke accepts the possibility for the same man to have distinct incommunicable consciousness at different times. An example of this would be a mad man, who would make different persons at different times. One is a man who commits mad actions, the other is a man who does sober actions. Implying that these are two different persons, human laws are not punishing the mad man for the sober man’s actions, nor the sober man for what the mad man did. Nevertheless, we punish a drunk man for the fact he commits when drunk or a man who acts in his sleep. Even though they may not be conscious of what they committed, we cannot prove that the drunk or the sleepwalker have two consciousnesses at different times.

Finally, suppose that self is determined by identity of thinking substance. Considering that the mind forgets past actions and recovers the memory of a past consciousness, there would be always two persons in the same body. For intervals of memory and forgetfulness would take their turns regularly. So, if we remove the consciousness from the substance, there will be no more man’s self. Only consciousness can unite remote existences into the same person and make alone self. This is why self should be determined by consciousness which provides more assurance to personal identity.  

Bibliography:

  • Locke, John, Essay Concerning Human Understanding in Modern Philosophy, an anthology of primary sources, second edition, edited by Roger Ariew and Eric Watkins, Hackett Publishing Company, Inc. 2009