This is in response to TheFountain in case I don't finish before someone else posts...
I do not think the idea of free will is incompatible with identity. Really we lack good terminology to discuss this issue in depth.
You asked how I can believe that some convicts are driven my chemical imbalances and some act more deliberately and yet still hold that three is no free will. I will explain.
Like I said, the terminology we have confuses a lot of things. For example, I say that I don't believe in free will, but it is obvious that we make choices every day. This is not a contradiction. I could say that the choice is an illusion, but you've heard that simple statement before. I believe it is something like that, but not so simple.
Even though I think free will doesn't exist, that doesn't stop us from needed to make choices in our lives. Imagine you're at sitting down at a restaurant and the waiter comes up to you ask asks, "What will you have tonight?"
As much as I believe in determinism, I must make a choice of my own will. That is choice, but not free will.
Now, let's say someone, call him Bob, had implanted a chip in my brain and can control my body. So when the waiter asks me what I want, Bob pushed a button and makes me say "steak." This was not my choice, nor was it free will.
I'm considering the first example, of me making my own choice. That is a deliberate act, but still bound by determinism. The second example is not the "fault" of the actor, but rather some other force beyond the actor's control.
So with the example of violent acts. One person's actions may be very deliberate and intentional and another person's acts may governed more by hormones and chemicals in their brain that they are not in full control over.
Ultimately neither have free will, and I see your point. My point was only that some violent criminals are not merely driven by simple "chemical imbalances" that can be easily fixed. Some people seem to be truly intent on harming others, and didn't just commit violence out of simple rage.
There's a lot of issues here. Let's take things slowly and cautiously, being careful not to misunderstand.
Now your issue about "identity."
What identity? If free will is completely predetermined then why isn't 'personal identity' predetermined as well? In this case what does it matter what personality is there or not? Your argument is that 'I' am merely a puppet being tugged about by some deterministic law. Why then was 'I' provided a personal identity? It is a conundrum that makes no sense.
I believe personal identity is "predetermined." That doesn't prevent unique personalities from existing. You're asking "why" we are provided a personal identity? I think you might mean "how." Let me know, because I'm confused by that last bit.
Either our personal identities were granted to us for the purpose of making decisions or we do not have personal identities, we only think we do. But then why would we have to think we have personal identities at all? Wouldn't it be easier if we were governed like insects? Or the Borg from Star Trek? One shared delusion? There has to be a reason why we were given individual identities.
I think you're asking why we are conscious. Or rather
how we are conscious when our actions are determined by physics. Why do we even think we can make decisions? What advantage does it give us? I think that's what you're asking.
Here is my answer. It's not that consciousness is an extra, unnecessary thing that sits on top of the rest of our brain. It's that it is an integral part of us. Without a conscious mind you couldn't make intelligent decisions, plan for the future, remember the past, or love a person.
Somebody has to be aware of the whole goings-on. And guess what? That somebody is you.