My last blog post discussed the notion that our intuitions are not trustworthy guides to understanding truths that are outside the bounds of our everyday experience. Relativity shows how our intuitions deceive us as to the nature of space and time, while quantum theory shows us the flaws in our common sense notions of matter and energy.
But there are many other ways in which our intuitions may deceive us. Much has been written about free will and whether this is an illusion (I believe it is). Bruce Hood has recently released a book called The Self Illusion, which argues that what we identify with is not a well-integrated self but a collection of competing drives and subconscious processes.
In this post I will introduce the idea that something is wrong with the very notion of personal identity itself.
By the notion of personal identity, I mean the concept that I as an individual have a necessarily unique and persistent essence of "me-ness" which distinguishes me from other people and indeed other collections of matter. The philosophy of identity has long been a topic of debate within the field of philosophy, and it seems to be a particularly difficult subject on which to build consensus.
By arguing that our intuitions of person identity are illusory, I'm not trying to say that they are totally without foundation. What I am saying is that if you think about them deeply enough, you encounter paradoxes and contradictions which imply that there is something deeply wrong with the way we usually think about identity.
The underpinnings of identity are not normally a big issue because our intuitions are usually up to the task of dealing with problems we face in everyday life. If we catch the perpetrator of a murder that happened ten years ago, we don't generally waste much time pondering whether the murderer is really the same man he was when he committed the crime.
But imagine he had a brain injury and he can no longer remember committing the crime. While you're at it, imagine that the brain injury has altered his personality and he is now calm and childlike where he was previously predisposed to violence and aggression.
It's hard to see the purpose of punishing such a man. The brute who committed the crime has effectively ceased to be, so there's no point in retribution. He no longer poses a danger to society, so there's no point in rehabilitation. The circumstances are unusual enough that even the deterrence value is without merit. After all few murderers are going to try to get a brain injury in order to avoid prison.
And yet our intuitions of personal identity cause us to see him as responsible for the crime and would demand that we hold him to account for it.
This is just one example of the kind of question we might ask if we question our intuitions of identity. For issues like these, and for metaphysical arguments I will develop in later posts, the issue of personal identity is worth discussing. I will do so in the following series of posts.