It seems a trivial question to ask how it is that I find no difficulty identifying myself with that five-year-old boy in the photograph, who has changed so much over the years to the extent that not a single cell in my body has been left unreplaced. Would a house be the same house if all the bricks had to be completely replaced by new ones?
A seemingly trivial question which has troubled the minds of philosophers since time immemorial and is still keeping them awake at night trying to solve this seeming mystery.
There is no question that our body replaces itself constantly, with some tissues like skin and gut lining doing so within a couple of days, while others taking months to do so.
Some would say that the possibility for self-identity depends on our own memory of our individual history. We remember the incidents through which we have gone, and all these form a biography that is uniquely ours. We remember our parents, our family, our teachers, our friends and colleagues, and it is this album of our life that makes us so different from anyone else, however close they may be.
There is no doubt that memory plays an important part of our identity
There is no doubt that memory plays an important part of our identity, enabling us to keep tab on who we are and how we have arrived at any particular destination. It may be stated that if and when we lose our memory, say after a stroke or through chronic disease like Alzheimer’s, we have lost our identity, at least as far as we are concerned.
We may still be recognisable to a third person, but we have become so detached, so cut off from ourselves and everyone else, that it is difficult to believe that we are still conscious of our own identity.
So what precisely constitutes our identity?
There is not one single factor that defines our identity. In the first instance, there is biological identity. I am biologically different to everybody else (identical twin excepted) because the blueprint for each of my cells depends on my DNA, which is uniquely different from everybody else’s.
So while each brick (cell) in my house will change over the years, the uniquely individual DNA marker is still precisely the same as what I had as a foetus and throughout my lifetime. To continue the analogy, all the bricks in my changing house have precisely the same markers I had as a child or even as a foetus.
The second factor determining my identity is psycho-sociological, or what might be looked at as environmental influences that interact constantly with my inherited make-up to make me the person I am today.
My health, education, wealth, position within society and every other factor which distinguishes me from anyone else, is determined by a continuous interplay between my inherited genes and the various environmental factors which work upon them.
If I was born in deepest Africa or in the North Pole, I would most probably be a completely different person to what I am today (even, for the sake of argument, if the same parents dropped me there!).
A third aspect concerning identity is the personal consciousness of this history. This is where memory comes in. One cannot appreciate one’s individuality without memory: when the latter is lost, so is one’s own appreciation of individual existence and personal identity.
So one could conclude that, while memory is an essential component of our understanding of our identity, it cannot be conflated with it. To use the inevitable computer analogy, memory is merely the hardware, a readily accessible depository of information, like a USB.
While one cannot have identity without memory, it is not memory that gives us our identity but all other factors which together plot to weave a uniqueness that lasts a lifetime.