In this article, I’d like to talk about an interesting topic in contemporary philosophy. Let’s dive right in.
Who are we? Some answers someone may throw out are:
- a person
- a mammal
- a brother, mother, sister, father, cousin
- a writer, painter, artist, singer, athlete
While descriptive, none of these answers prove sufficient for the question. I asked what we are, not how we relate to other people. We are only brothers because we have a brother. We only identify as artists because some are athletes, and we need a way to distinguish from them. We are people because others are gorillas. We are mammals because others are insects. An exceedingly large part of our identity is derived from our relationships to others. While this suffices for describing our identity to others, to making clear where we stand in relation to the rest of the world, it missed the core philosophical argument: who are we, in our essence?
Philosophers who are asked this question may respond:
- we are our body
- we are memories, and experiences
- we are our mind
- we are a soul/essence
- a point in time
These answers are closer. Yet, drawing on the work of contemporary philosophers and neuroscientists, most (all?) of them miss the mark. Let’s start with disproving some of the easiest ones, and work towards arguing against the more tricky ones.
We are our body. All you need to disprove this is a nudge. Yes, a nudge, that bruises your skin, possibly breaking a bone, harming some part of your body. If your personal identity is truly linked to merely your body, the slightest injuries that inflict bodily harm would be removing shreds of that personal identity, cut by cut, scrape by scrape. Consider the age-old thought experiment, the Ship of Theseus. It goes like this: if you replace all the pieces in a wooden ship with new wood, is the ship the same? This ship bears no original parts to the old ship, yet some would still say the ship remains the same. The same logic can be applied back to us. The vast majority of our cells are replaced during our life. While some cells, such as those in the brain and heart are not replaced, by this logic, our personal identity must decay, or irrevocably shift during our life outside of our control, so that when we are old and decrepit, who we are bears as much resemblance to who we were when we were young as to a whole other person. But this doesn’t make sense. While people admit that they change over time, when they are old they wouldn’t say they are 0.1% of Asher, they would say they are still Asher. So unless we are willing to accept this wildly unintuitive conclusion, there must be some guideline, some guardrail apart from our physical existence that guides our identity even as our body is replaced. So what is this thing?
Well, many propose that it is the memory, or experiences. John Locke thought so. His famous conception of the Tabula Rasa proposed that every mind was born a blank slate, a slate to be furnished with new experiences, memories, and an eventual personal identity. As those memories and experiences continue, the personal identity is etched out and developed. Locke believed that personal identity was a continuous stream of ongoing processes, or consciousness, and that you were you as long as you remember your own thoughts or consciousness. This raises a couple questions. First of all, what about the old people? As we grow older, does our identity crumble away behind us, until we remember nothing at all. This is a somewhat depressing view: if our identity is linked to mere memory, alzheimers or dementia are a gateway to death—that of the personal identity. But that alone is not enough to make the argument that identity is more then a collection of memories. Consider the famous split brain problem.
With modern neurosurgery, it is possible to sever the corpus callosum, which is the part of the brain responsible for the communication between the right and left parts of the brain. It is conceivable that someone could quickly have their corpus severed. Say you do this while you are taking the SAT. You are struggling with a different math problem, and you have narrowed down the possible answers to A and C. Instead of going through both, you think, why don’t I just split corpus callosum, and disconnect my left and right sides of my brain, as both sides (left and right) have been proven to act independently of each other (this is the kicker). Suddenly your corpus is severed, and now you have two distinct consciousnesses: one that you use to check answer A, and one that you use to check answer C.
What happens when you try to apply Locke’s theory of consciousness? Well, you would get either 1 person, 2 people, or 0 people. After splitting your brain for this tricky SAT problem, if identity is solely linked to a chain of memories or experiences, it is impossible to decree there is now only one identity—you have the side who has checked A and the side who checked C. The identity of left/right brain are fundamentally altered, their experiences are different. Like wise, one cannot simply decree that the identity disappears overall, as the stream of consciousness is continuous in both hemispheres. So what does this leave you with? Two personal identities that are both the original. Yet this is also implausible. The original person cannot be identical to both of the two remaining personalities, which suggest a contradiction: identity is both irrevocably lost and preserved. Therefore, continuity of memory cannot be the sole mark which personal identity is based on. If one is able to split their brain into two continuous streams of memory, they create two distinct personalities which both lay claim to being the original one.
So sorry Locke, the claim that our personal identities equate to a conscious stream of memories cannot be true. This is post 1 of 2, in the next one, I will dive into the way other philosophers, like Derek Parfit, think about our personal identity.