Philosophy Now magazine has an interesting article on the problem of identity – how we have the impression that we are the same person, despite the fact that our personality, preferences and even cognitive abilities may change from moment to moment.
It’s a problem that was most famously tackled by 17th century philosopher John Locke but is still relevant for understanding the issues of identity and the self in contemporary cognitive science, as well as for informing complex judgements on free will and responsibility.
Suppose a man has committed a crime whilst drunk or undergoing temporary amnesia. Suppose also, that because of his mental state at the time of the offence, he genuinely cannot remotely remember a thing about it. Clearly on the evidence of witnesses ‚Äì and perhaps he was caught in the act ‚Äì it was his own body, the same man who now stands in the dock, who did it. But was it the same person? Should the present person be found guilty of the crime if the drunkenness or amnesia had so changed his psyche that, at the time, he ‘wasn’t his true self’? Can he rightly claim that at the time of the incident the occupant of his body was a different person altogether; or perhaps some fractured component of his own psyche that couldn‚Äôt rightly be described as ‚Äòhimself‚Äô?
Psychological continuity was, Locke claimed, the answer to the question. The accused, considered as a man, the physical being, is certainly guilty. His own hand struck the blow, his own voice had risen in anger. But if the person, the psychological being, cannot remember one atom of it, then he is not guilty.
But though Locke’s theory answered the question, it‚Äôs not certain that it solved the problem; for it raises a paradox that will try the wits of the jurists: the man in the dock may be guilty, but not the person in the man! And if the man is punished, he will experience the pain, but the wrong person will suffer it.