Who are you?

Who are you? What are you? What makes you be you?

Your body is not you; every cell in your body is replaced every seven years or so, thus - should you think your body composes you - you are a completely different person than you were eight years ago.

You could say you’re an organism, a whole being that can survive cell replacement, but you are not a whole being. If medical science developed a way to do proper brain transplants and moved your brain to another body; would you still be you? If no, then you’re now a different person and cannot be you. If yes, then your whole being is not you.

Of course, what would logically follow is that you are your brain. But then the same as above can be said; if your mind, memories, experiences, skills, and everything else were transferred onto a blank brain, then would the body holding that brain be you? What if the copied mind was transferred to two (or more) brains? Logically one person cannot be in two (or more places), thus neither of the minds can be you.

Of course, should the mind be the vessel that defines “you” then you are still not you, because your mind, thoughts and so on are constantly being changed and reshaped.

So, who are you?