One of the central problems in metaphysics is that of identity: what is it to be a person?
Does your physical manifestation constitute your identity? Would you be the same person if you lost all four of your limbs? What if you were burned beyond recognition in a fire? Are any of your physical attributes pertinent to your identity?
What about your personality? Is there some unchanging essential component of your personality that you retain from the time you’re born until the time you die? This illustrates the problem of change and how it relates to identity.
There are many theories that have been proposed, some going to great lengths to try to address counterpoints and details, and still others dismissing the entire discussion altogether. Religion, for example, has the convenience of a “soul” to tie down to, but there are a variety of ways to address the problem across many different schools of thought.
It is a very interesting concept to contemplate. I find this to be one of the hardest problems to address in metaphyics, as there doesn’t seem to be any happy medium place to draw the line.
It really is a nice theory. The only defect I think it has is probably common to all philosophical theories. It’s wrong.
Saul Kripke
no man steps in the same river twice