The problem of personal identity is one of the main problems that are very preoccupied with contemporary philosophy. What makes a person that person? (Olson, 2015) Let's take your personal identity, for example. We can say that you are still the same person, although your neck, weight, color, place and many other physical characteristics have not changed. If we deal with your choices and pleasures, not your physical features, you meet the same conclusion: You are still your own when you have your faith, your political opinion, the type of music you listen to. So what is it that keeps you from being at different points in the world, at different times, with different beliefs and with you all the time? According to some, the answer is hidden in a very special part of our central nervous system. (Smart, 1959) According to others, we are some kind of algorithm other than some kind of algorithm that our brain works. (Piccinini, 2009) In fact, opinions are often encountered in the history of thought, apart from our material, whether we have made a very special statement or already exist. The problem of personal identity is closely related to very basic philosophical issues that try to explain our mental activities at this point.
Instead of answering a great philosophical question about the personal identity of the questions of the doctoral theses written on philosophy of mind in many loyal universities of the world today, let us consider a problem that is an introduction to the same subject: if your brain was successfully transfigured to another body, would you still be the same person? I think many people will answer this question, "Even if I feel very different in such a situation, I will continue to live on that body again." So much so that Joel Pust gives this answer as an example of human intuition. (Pust, 2012) In fact, there was a system of thought centered on the brain that preceded the development of modern neuroscience. For example, the mental states of the belgian dille, now known as the Edwin Smith Papyrus, which were written in 1700 BC and attributed to an Egyptian vizier who lived in 3000 BC, are related to the brain. (Minagar et al., 2003). Of course, the next time in Egypt, this experimental viewpoint is based on mystical, supernatural, and only empty speculation, the brain has left its place in people's eyes. In ancient Greece, thinkers such as Croton Alkmaion and Hippocrates are accusing all of our thoughts, cognitive processes, psychological problems such as sleepwalking, obsessive compulsive disorder, to be related only to our brains, and accusing the heart centers of being a charlatan (Gross, 1987, 843-44); Aristo, who lived a century or so after them, claimed that the mental processes were carried out in the heart, and that the task of the brain was only to cool the blood in the body. (PA 653b-Pa 656a)
Though the opposition of the heart and brain in the history of thought still exists through cultural and religious beliefs, I think that when the subject organ is born, the general attitude will be in favor of the general attitude in terms of our personal identity. But Derek Parfit gives us a thought experiment that shows that this is not so easy: Think of an accidental body (parts outside your brain) becoming dysfunctional. The two halves of your brain that are identical (with the same functions) have been transferred to two different bodies whose brains have become inoperable. Let's just say the surgery was successful. When these two people (Donald Trump and Kim Jong-in) wake up to where two pairs of your brains are being witnessed, they immediately run into your family, unaware of what is happening without talking to them at once and start talking to them like you are. In an opinion, because your brains will be in those bodies, in fact they are you. So your body is not your changing brain! You are trying to convince people that you are the person who welcomes your family and your friends with different faces, different body sizes, two different sound colors. If you look at your family from the eyes of your friends, you claim that you are in the middle, but there are two people quite different from each other who have no physical appearance at all. Just think that these two people are accusing each other of lying.
Parfit mentions three scenarios that are candidates for explaining this situation. In the first scenario, both of these two people are different from you; because you do not actually kill the brain transplant. But it is unlikely to blame these surgeries, where your brain has been successfully transplanted in two different bodies, with a failure in the form of your death. In the second scenario, you are still alive as one of these two people. So you are only one of the brains in Trump or Jong's body. Therefore, only one of Trump and Jong-Un, who tells you about your memories claiming to be your friends, is telling the truth. But this scenario is also problematic because we have no reason to choose one from these two people. In the third scenario, these beings, who appear to be two different people, are actually one person who is unaware of each other. So after the surgery, you continue your life, both in Trump body and Jong's body, without being aware of the other yourself in a sense. This third scenario does not make much sense to the ear. Parfit claims that since the three scenarios are unlikely, the problem actually lies in our understanding of personal identity. Claiming that the problem is related to the concept of identity, he thinks that this concept must be revised.
Of course, the technical details related to the concept of identity in Parfit's argument here are not something that this short essay can summarize. However, our response to the scenario above pushes us to a deeper philosophical discussion in this regard. For example, can scenarios other than the above scenarios be produced? Or are there any of these scenarios that can be defended? If we look a little further out, can this experiment of thought itself be problematic? Is it even possible to get away from the question, perhaps by claiming that all the thought experiments are problematic? In philosophy it is important how we respond to the questions, how we approached the issue rather than the feeling which we are close to. Such an endeavor aims to keep the connection of our concept network with our experience under control. As a result, this type of question about personal identity and the meta-philosophical questions about whether these questions are meaningful affects positively the network of concepts that are organized and other disciplines working on personal identity through the relation of this concept network to our experience.