If you haven’t, go check out Part 1!
Picking up where we left off: if we look back at our answers to the original problem, we might not feel so confident about either one, right? I’d hope so, because neither side truly resolves the problem. If we look at the first answer — that Ship A and Ship B are different because their physical makeup aren’t the same — then we have to believe that we also aren’t the same person we were seven years ago.
But that doesn’t feel right. Although our personalities might change a lot in seven years, most people probably believe that there is something that truly makes them them, and that this “something” has been there for their entire life. They might call it many things — their soul, their mind, or just their character — but in the end everyone has a sense of it.
But some people might have trouble agreeing with the existence of souls and all these vague ideas about “underlying qualities.” For them, the science is clear, and the science says that we are never the same thing; that we are constantly changing. But there also might be some facts that allow a compatibility between the two differing ideas.
You might remember in Part 1 that I didn’t say that every part of your body is replaced every seven years. I actually said almost every part. It just so happens that this irreplaceable part is also the most important organ in your body: your brain. Unfortunately for us, our neurons don’t regenerate. But on the other hand, our brain cells last a very long time. Once our brain stops growing in our mid-20s, the neurons we have at twenty-five will be the same neurons that will carry us all the way to old age. So unlike your hand, which will be replaced many times in your life, your brain will always remain.
What does this mean for the scientifically-minded person? Well, it should mean that there is no problem: everything that makes you you, like your memories, are stored in your brain. And since the brain never physically changes then neither do you.
However, I don’t think it’s so simple to separate our bodies from our brains, given that they are fundamentally linked and can’t exist without each other. On top of that, are memories really the best basis for your identity given that they are never set in stone and often wither away in old age? Does that mean that as you grow older, you become less and less of your original self? And let’s not even mention what might lie in the future with cybernetic brain enhancement. Will you still be yourself when half of your brain is machine? What about when it is completely cybernetic?
Unfortunately, I’m out of time! These are questions you’ll have to wrestle with on your own.
In the end, it seems the only fact about ourselves that never changes is that we are always changing. As Heraclitus says, “It is not possible to step twice into the same river, or to come into contact twice with a mortal-being in the same state.”
Matt is in his second year of Algonquin’s Professional Writing program. He enjoys writing, editing, reading history and philosophy, and not talking about himself.