Locke’s account begins, as most great Philosophical works do, with a distinction. Locke distinguishes between sameness of substance, man (or woman) and person, with the former not our concern. According to Locke, a man is nothing more than a certain animal, so the physical body that we have. Sameness of man, therefore, is just sameness of physical body. However, this is not what Locke takes personal identity to consist in. Locke defines a ‘person’ as, “…a thinking intelligent being, that has reason and reflection, and can consider itself as itself, the same thinking thing in different times and places.” He goes on to state that sameness of person consists in sameness of consciousness, which we take to mean memory.
This is referred to as an account of psychological continuity, because there is a continuing of the psychological features of the person – that is their memory, their beliefs, their personality. For Locke, memory is what is most important. So if a person X, can remember doing an action Y, then person X was the person who performed that action. This what Locke refers to as: remembering from the inside. We have special access to our memory of past events, because we were that very same person that did them.
There are two cases which bring out Locke’s thought. One is a case that Locke himself considered: the prince and the pauper. If the consciousness or mind of a prince is put into the body of a pauper, and the pauper can remember being the prince, then we could say that the pauper is the prince! A modern day example is a case where two men (Brown and Robinson) are in a car crash and Brown’s body but not brain survives, but Robinson’s brain but not body survives, so Robinson’s brain is transplanted into Brown’s body. Locke would say that this new creation is the same man as Brown, but the same person as Robinson, if they can remember being Robinson, which we would suggest, because they share a brain, that the person would.
What this post has attempted to establish is what it means to be the same person throughout time. Why does this matter? Simply put because we reward and punish people for actions we say they committed. When we punish Sarah for murder, we are saying that the Sarah in court was the same Sarah as the one who plunged the knife into the victim’s neck. Locke’s theory of personal identity gives us a basis for coming to this conclusion. Sarah can be said to be the same person that committed the crime because it can be proven that Sarah remembers committing that crime. More on this later.
Let’s return to a case previously discussed, the prince and the pauper. Locke’s theory forces us to conclude that because the pauper can remember the prince’s past life, the pauper is the prince. From this is follows that the pauper’s body would be responsible for all of the prince’s actions prior to the transfer of consciousness and not responsible for the any of the pauper’s prior actions. Where we see the pauper’s body, the Law must see the prince’s actions - according to Locke. The question to be asked is “who” exactly are we punishing if the pauper’s body is put in prison. It seems fairly intuitive that, after the transfer of the prince’s memories, thoughts etc, it would still be the prince - despite the physical change.
Another case to be considered is that of children and the mentally impaired. Locke’s definition of “person” (thinking, intelligent etc) would render children and the mentally impaired not (at least full) persons. Oddly enough, the Law does exactly the same. We hold children and mentally impaired humans much less responsible, often to the extent where they are not held accountable at all, for their actions in virtue of the fact they are children or mentally impaired. Locke’s theory gives us a reason why we do this: children and the mentally impaired are, in the legal sense, not persons and therefore we do not hold them responsible in the same way.
In a legal sense, therefore, Locke’s theory seems to have a lot going for it. However, in a crucial way it falls down. Let’s return to Sarah and a statement made above: “Sarah can be said to be the same person that committed the crime because it can be proven that Sarah remembers committing that crime.” This leads to two fundamental issues:
- Believe it or not, it is virtually impossible to prove what someone remembers and what someone doesn’t remember
- To forget something would necessarily be a defence in a court of Law.
The second one is just false. Sarah stands up and claims to have been under the influence of alcohol when she murdered the victim and therefore cannot remember doing it. Let’s suppose it can be proven that she did not remember it. Locke’s theory now forces us to believe that a different person committed the crime. Again, it seems uncontroversial to argue that we do not punish criminals for actions that literally another person committed. Do we acquit Sarah? Taking Locke at his word would force us to do so. Intuitively this seems wrong, Sarah is surely guilty of something, even if it is on diminished responsibility - and, indeed, the Legal system tends to agree. We assume that people remain that person even throughout lapses in memory - and hence we can punish them (or reward them) for actions they cannot remember committing. Sorry Sarah, it seems your appeal to Locke’s theory of Personal Identity won’t work.
There are limitations to Locke’s theory. He may help us answer questions of personhood when we consider princes and paupers or why children are not held accountable, but his theory is, at least in part, not compatible with our modern legal system. Can’t remember doing something? Tough luck!