On the topic of personal identity and brian transplants. The person whose brain is used is saved if you believe in John Locke. Locke holds that consciousness can be transferred from one soul to another and that personal identity goes with consciousness. Consciousness can be transferred from one substance to another, and thus, while the soul is changed, consciousness remains the same, thereby preserving the personal identity through the change. On the other hand, consciousness can be lost as in utter forgetfulness while the soul or thinking substance remains the same. The psychological states criterion holds that our memories constitute our identity over time. You are the same person were at 10 years of age because you have a continuous set of memories that contains all those that you were at 10 years of age plus others than continued after that year. However there are problems with this view when considering Locke's theory. Objections he faces includes that memory is not needed, false memories, and Thomas Reid's Brave Officer as well as David Hume's opinion. Thomas Reid suggested a problem regarding Locke: suppose there is a military officer who at 25 is a hero in battle who remembers getting flogging in his childhood, age 10. Later at age 65, he recalls the heroic deed at 25, but cannot recall the flogging, even though it defined his personhood at 25, therefore is he still the same person flogged when he was 10, even though he can not recall it? Locke does not have away out of this problem. David Hume's theory is even more radical than Locke's through denying we even have a soul as there is no separate, permanent self that endures over time hence personal identity is fication. Locke believes that personal identity through time consists in having a continuity of consciousness since it is sent by consciousness that our various thoughts and sensations belonging to the same person. It is via memories that the person possess this connection of consciousness, for memories link the past consciousness with the present. As well as you remember doing an act 10 years ago, you were still the person who did that act- regardless whether you had this body or another- for after all, our cells are constantly replacing one another so that every 7 years we essentially have a new body. In reference to the question, Is an entirely new person made?, Under these conditions, there is the same soul but a different person. These affirmations amount to the claim that the same soul or thinking substance is neither necessary nor sufficient for personal identity over time. Would the post-operative identity person remain the same over time? We should speak of survival of the person, rather than the identity of the person. Persons, a physiological states, survive, and gradually merge (like Theseus's rebuilt ship) into descendant persons. Your memories gradually emerge from the 15 year old who gradually developed from the 6 year old and before that, the 1 year old who bore your name. Derek Parfitt, a British philosopher who specialised in personal identity, rationality, and ethics. He is widely considered one of the most important and influential moral philosophers of the late 20th and early 21st centuries. His point is that we are going through significant changes all the time, so that as we have new experiences, we take on new selfhood. Something in us survives, but with a difference. It encourages a sort of general utilitarianism, for since our distant interests really are not as closely related to us the needs of our contemporaries, we could be free to work for greater good. The third criterion , the brain criterion of personal identity. Our memories are contained within parts of our brain, so we might want to say that having the same brain constitutes the same person. But also has difficulties as brought out by Derek Parfit. It is well known that if the corpus callosum, the great band of fibers that unites the two hemisphere of the brain is cut, two different centers of consciousness can be created. When either side of the cerebral cortex of the brain is destroyed, the person can live on as a conscious being. In my opinion, believe that brain transplants are unethical. Yes, this mind is mine but I can't look past the physical changes. It is not my body, even though as the brain I have control over it. Personally, I have a problem with not being in control of my body which is why I do not experiment with drinking or drugs whatsoever. This body is 99% body parts that is someone else. And for me I see it as I won't come by to pick up the package of body parts they will have left specifically for me. I don't want them. I don't want their heart. It's not theirs anymore, it's just a heart now and I already had one. I don't want their lungs. This body is not mine.