Question

Consider patient TA. TA was a vibrant man who worked hard his whole life, loved kittens, relished a good meal, and had a kind word for anyone within earshot. Around 75, TA developed Alzheimer’s. Within 2 years, his close friends and family said he was no longer the same person. He didn’t recognize them, was angry and ill tempered most of the time, and preoccupied with what was wrong with his life.

What would John Locke say about this man and whether or not he is the same person? What would Derek Parfit say about this man and whether or not he is the same person?

Answer 1

John Locke hels that personal identity is a matter of psychological continuity. In other words, he considered personal identity to be founded on consciousness or memory, and not on the substance of either the soul or the body. Therefore, John Locke would conclude that TA is not the same person anymore.
On the other hand, Derek Parfait asserted that personal identity does not matter for survival, memory, or moral responsibility. He argued that there is no unique entity that underlies the mental experiences and dispositions that may be attributed to a single individual at a given time. Therefore Derek Parfait would spend time debating about TA's personal identity.