What is free will? This book presents the views of four different philosophers on the topic. The book defines free will via a question - what are the prerequisites for someone to be held morally responsible for their actions? What is especially great about this book is that the authors could see each other's sections in the book so that as the book progresses each author can refer to what the authors in the sections before them said. Then at the end each of the four authors gets another chapter in which they can refer fully to what the other three authors said and respond. I especially liked the fact that the authors really engaged with each other's points rather than just throwing stones at each other. Below I explore the key points that each of the authors made and why I'm not fully buying any of it.
The key question seems to be determinism versus non-determinism. Determinism means that everything in the world is pre-ordained. That the universe is just a big clock work machine.
Non-determinism means that there is randomness in the universe. That we can't know the outcome ahead of time.
To me this is a distinction without a difference. From the perspective of moral responsibility if I did something because I have burned into my brain "If X then Y" or if my brain says "If (X and Random() > 3) then Y" doesn't make a bit of difference. I'm still a machine with no real say.
Which gets to the real problem that all four authors struggle with. If we have free will, if we can make "free" choices, then this argues that there is something inside of us that can affect the universe without being a part of the universe. Because if something is part of the universe then it is influenced by the universe in which case how can we really say that someone is morally responsible for their actions? In other words if a child is raised to believe that enslaving black people is just fine then how can we hold that child responsible for their actions in enslaving black people as an adult if they literally had access to no other idea? Moral responsibility would seem to call for some ability to act independently of the rest of the universe.
One of the names given to this ability is the "Unmoved mover", another is a soul. This idea that some such mechanism exists has had a long history in the free will debate but is currently out of favor because we can't find any scientific basis for believing in it.
The four views presented in the book are:
Libertarianism - Libertarians (in the philosophical sense) are what are called incompatibilists. What this means is that they don't believe that free will is compatible with a deterministic universe. But Libertarians affirm that that we have free will. So first the author has to show that the universe is non-deterministic (since, being an incompatibilist, they don't believe in free will in a deterministic universe). This is done mostly by alluding to quantum mechanics which works on probabilistic rather than deterministic laws. Of course this doesn't prove the universe is actually non-deterministic since in theory what appear to us to be probabilistic outcomes might actually be pre-ordained. But where the author runs into real trouble is trying to explain the unmoved mover. He really seems to argue that just having a random component is enough but as I explained above that isn't compelling to me as an argument for free will. So in the end the author throws out some chaos theory and quantum mechanics as being present in the brain as a possible thesis on how the unmoved mover exists. None of it was really compelling to me.
Compatibilist - This author argues that free will is consistent with a deterministic universe. But he does this in a very sneaky way, he redefines the question. He essentially argues that if you can do what you 'wanted' to do then you have free will. But what is never usefully touched upon is how you came to what you 'wanted' to do. In other words if what you 'wanted' to do was what was pre-programmed into you before you were even born then in what useful sense is that free?
Hard Incompatibilism - This author essentially makes the arguments I'm making above that deterministic or non-deterministic, without an unmoved mover, which nobody can find, there is no free will. So get over it. We don't have free will. That logic I can buy (even if I don't like it) but where I think his arguments fall apart is when he tries to argue that it's just fine if everybody knows they don't have free will. That this won't rip our society apart. I tend to suspect that someone who truly believes they don't have free will will just use this as an excuse to do horrific things (not that humans have ever really needed such excuses). It's tempting to argue that if Hard Incompatibilism is correct then discussing it is useless since everything we will do is pre-ordained. But actually that doesn't need to be true even if Hard Incompatibilism is correct. I can write a program that says "If "I have free will" then "be nice" else "Kill everyone". It might not be a free decision but it's still a decision. So even if one doesn't believe in free will, arguments about the psychological effects of Hard Incompatibilism are still relevant since there are consequences to adopting those beliefs.
Revisionism - This author is also trying to change the question. Essentially he wants to redefined free will so that it works in either a deterministic or non-deterministic universe. This is really a compatibilist view except that even if compatibilists can be shown to be wrong his argument is that it doesn't matter because he is redefining what free will is to essentially be what the compatibilists claim (e.g. the right to do what you wanted to do even if what you wanted was pre-programmed into you). I tend to have a bit more respect for the revisionist author's arguments than the compatibilist author's arguments because the revisionist author is crystal clear about what he is doing. That is, changing the rules of the game.
So in the end none of the views really floated my boat. I do think it would be very interesting to further explore the consequences of Hard Incompatibilism. I have a suspicion that there is a Pascal type wager in here where the 'best' thing to do is pretend there is free will until such a time as we have proof positive (and don't ask me what that would look like) that we don't have free will.
In any case, I'm going to look for more books in the series. I really like the idea of allowing philosophers to discuss things with each other. Their questions and challenges help to bring clarity to otherwise difficult points.