So, I’m an atheist, I’ve let go of mystical notions such as gods, spirits etc. Therefore I don’t believe I have a soul. Then what makes me me? It can’t be the stuff of which I am made; the atoms, ions, molecules, cells, etc. since they are all being continually replaced, and after all, what would be special about any atom that would change my identity if it was replaced with another?
The only possible answer can be that I am the arrangement of the stuff of which I am made, most particularly, the arrangement of the cells and chemicals in my brain. A scarily minimal thing on which to hang one’s identity, but it fits the facts:
More and more, it becomes clear that personality (to which I think we would all agree identity is greatly tied) is an emergent property of brain function. Specific characteristics in brain chemistry and structure are linked to specific psychological problems or profiles. Neuropsychology is the study of how the two are linked, and it is still in its infancy – the brain is so complex that untangling the huge numbers of processes and linking them to outwardly expressed behaviours is incredibly difficult – but, as usual with science, the more time passes, the more can be explained by a good understanding of the processes involved.
We start life with a brain which has certain formative characteristics. There are many arguments to be had about how much of our personalities is inbuilt and how much a product of our environment, but it is clear that the answer will turn out to be “a bit of both”. For instance, I know that I have continuity with the child I used to be, but I have clearly changed to some extent, with different needs, desires, attitudes and opinions. These have arisen as I have interacted with the world around me, adding to the experiences on which I draw for further interactions in an ongoing feedback loop. I am even part of the environment with which I interact – ever felt guilty about an action and resolved to change? That’s you being your own environment – cool, huh?
Thus, as time goes on, the pattern that is me has grown and changed, while retaining sufficient characteristics to claim a continuing “self”, and when I die, that pattern will break up and cease to exist. The only real continuation is in the effect I have on others who will remain afterwards, and their effect on yet others, etc.
You are an ephemeral arrangement of stardust. So be good to yourself, and try to leave a better environment for all those other arrangements to come.
Just a tad belatedly 😉 I’d like to make an adjustment to my postulate – we are not the arrangements themselves, we are the processes that occur within those arrangements. Hence when those processes cease, so do we. And if those processes can be restarted before the substrate deteriorates, back we come!