I'm participating in a university course on free will. On the online forum, someone asked me to summarise Eliezer's solution to the free will problem, and I did it like this. Is it accurate in this form? How should I change it?
“I'll try to summarise Yudkowsky's argument.
As Anneke pointed out, it's kinda difficult to decide what the concept of free will means. How would particles or humans behave differently if they had free will compared to if they didn't? It doesn't seem like our argument is about what we actually expect to see happening.
This is similar to arguing about whether a tree falling in a deserted forest makes any noise. If two people are arguing about this, they probably agree that if we put a microphone in the forest, it would pick up vibrations. And they also agree that no-one is having the sense experience of hearing the tree fall. So they're arguing over what 'sound' means. Yudkowsky proposes a psychological reason why people may have that particular confusion, based on how human brains work.
So with respect to free will, we can instead ask the question, “Why would humans feel like they have free will?” If we can answer this well enough, then hopefully we can dissolve the original question.
It feels like I choose between some of my possible futures. I can imagine waking up tomorrow and going to my Engineering lecture, or staying in my room and using Facebook. Both of those imaginings feel equally 'possible'.
Humans execute a decision making algorithm which is fairly similar to the following one.
List all your possible actions. For my lecture example, that was “Go to lecture” and “Stay home.”
Predict the state of the universe after pretending that you will take each possible action. We end up with “Buck has learnt stuff but not Facebooked” and “Buck has not learnt stuff but has Facebooked.”
Decide which is your favourite outcome. In this case, I'd rather have learnt stuff. So that's option 2.
Execute the action associated with the best outcome. In this case, I'd go to my lecture.
Note that the above algorithm can be made more complex and powerful, for example by incorporating probability and quantifying your preferences as a utility function.
As humans, our brains need the capacity to pretend that we could choose different things, so that we can imagine the outcomes, and pick effectively. The way our brain implements this is by considering those possible worlds which we could reach through our choices, and by treating them as possible.
So now we have a fairly convincing explanation of why it would feel like we have free will, or the ability to choose between various actions: it's how our decision making algorithm feels from the inside.”