Who am I?  Who is anyone?  How do you tell if, after going through some transformational experience, you are still you?  These are the sorts of questions about identity that keep me up at night.

One of the core issues of identity to me is the difference (or gap, I guess) between the way I make my thoughts (let’s call it agency) and the sum of my experiences (let’s call it memory).  Throughout my life, as I experience new things, I am continuously altering myself in tiny ways.  I like to think of myself as the combination of my memories, but this immediately leads to a problem: if I somehow lost my memory, or if, in the course of aging, I became unable to recall some memories, am I a different person entirely?  This bothers me – I think that I have an unbroken chain of identity through my life, so that each moment I can still lay claim to being “me”.

On the flip side, if I were to suffer some huge shift in personality or ability to think, would that alter my agency and thus my identity?  This seems like a more likely candidate to change Dave from “me” to “someone else”.  Of course, once again we consider the case where over time, I subtly but surely alter my thought patterns in response to experience.  Is this different than the radical shift I proposed first?  My guess is it’s not very different at all.  So where alteration of memory seems irrelevant to my identity, alteration of agency seems highly relevant.

There’s another factor – the continuity of my physical body (by which I mean brain) – but I choose to discount it (see my posts on Free Will).  That’s because I think the relevant factor in identity is some combination of memory and agency, and not physical being.  I think that if a person could somehow be transferred into pure energy or information (as in, running on a computer system), the chain of identity for that person could remain unbroken and they would still be “them” (curse you, English, for no neuter third person singular for individuals!).

This brings us to the extreme cases:

  • Teletransportation – I think I am still me.  The continuity of the physical body is not relevant to me… but there’s yet another factor here: my BELIEF that I am the same person.  Dennett considers this in his essay Where Am I? In the case where the teletransport can make a copy, which is the real me?  Are both the real me?  What does that mean for my conception of identity?
  • Replacement of Brain with Machine – This one gets me thinking again about how agency is represented.  Maybe there’s something really complicated about natural brain changes over time that this replacement with machine parts couldn’t capture.  Another random thought – this means that a computer simulation could potentially model me and claim to be me… would it be?  I want to say “no” but I can’t really give a reason – I don’t think that the initial biological organism has any special claim of primacy here.
  • Soul Removal – When the issue is forced, and I have to say whether I believe in a nonphysical soul, I have to say not really – there’s no particular evidence to convince me, and I feel like the universe is complex enough to handle all of my existential questions without the need for hidden variables.  As to my answer to the question, I think I am still me… but I would feel bad.

Here’s a parting thought: I often stop and think, why is it that I am in this moment, thinking this thought, of all the possible moments I could be living as “now” – and of all the people I could be?  It’s very frustrating to be unable to even consider the question of why in a thorough manner with respect to this problem of identity.