This book is hands down the best introduction to the issue of "free will" that exists today. Kane is writing to the beginning philosophy student, but I assume a Phi. prof who has never taught on free will, or spent much time studying the issue, would profit from this book.
Kane's book is both extremely clear on the issues surrounding free will, it is also not too technical, and it also manages to bring the reader up to speed on what is a very technical, wide-ranging, and sophisticated debate.
Kane is a libertarian about free will. This means that free choices or actions are incompatible with determinism, and also that the agent who acts or chooses is ultimately responsible for those actions. Kane holds that there may be times when a person's choices and actions are the outcome of some prior cause outside of the person, but for this person to be responsible and free she had to, at some time in the past, be responsible for forming her character, for setting her will in a direction. This forming is "up to her" and is indeterministic. The agent had alternative possibilities, and formed herself one way rather than another.
I am a compatibilist. That means I believe that free will (any freedom worth having) is compatible with determinism. Kane expressed my position very well (as far as the philosophical aspects of it, as a theist there's more I'd like said). He provides the reader with a brief history of compatibilist (classical compatibilism of the David Hume, Jonathon Edwards sort) accounts of what it means to be "free" and what it means to be able to say you "could have done otherwise," before focusing on contemporary compatibilist positions. I believe his presentation of my side was fair and strongly argued. In fact, I think it was so well-argued that I believe most readers will find Kane's argument for libertarianism (towards the end) not-intuitive and unable to deal strongly with the objections put to libertarianism via compatibilism.
This book also focuses on moral responsibility and what it is to be a proper subject of ascriptions of praise or blame. What is it to be responsible for your actions? This is important because many people tie questions of moral responsibility and freedom so close as to be almost inseparable, such that if one can (say) show that one's actions or choices can be morally responsible even if determined, one has shown that one can be free even if determinism is true. Of course no account of moral responsibility can be properly done without reference to what has been called, "Frankfurt-type counter examples," after the philosopher Harry Frankfurt. Here's a quick rundown:
Many say that an agent cannot be held morally responsible for a choice or an action if that person could not have chosen or acted otherwise. Seems fairly intuitive, right? Not so, said Frankfurt. Imagine someone locked in a room, though they don't know that they are locked in the room. The door has a glass window in the middle of it so that you can look out. Now, say you hear some screams coming from the hallway outside the room. You look at the window and see a woman being attacked. You decide that you don't want to help her and you sit on the bed and turn on the boob tube. Are you morally responsible? Even though you couldn't have done otherwise?
Some say, "Yes, because even though you couldn't have done otherwise through no fault of your own, you could have chosen to do otherwise, i.e., made the choice to try and help. But Frankfurt just tweaks the examples. He asks us to consider a controller, Black, who implants a device in your head such that if you choose the way he wants he will do nothing, but if he sees that you're not going to choose the way he wants, he will press a button and make you choose his way. Now say that you end up choosing the way Black wanted (say, to vote for a poor presidential candidate), so he never had to press the button. Are you morally responsible for your choice? It would seem so. After all, you made it, you were not forced, you presumably had reasons to vote the way you did, etc. So it looks like ability to do otherwise isn't necessary for moral responsibility, and then also freedom.
There are responses to the above, and then responses to the responses. The issue is a very detailed one, as you can see, and Kane walks you through it like a skilled scout master.
Kane even allows that some particular actions/choices you do you may be held responsible even if you couldn't have done otherwise. But, Kane says that you would not be ultimately responsible if you were indeterministically able to form your character some time in the past. At some point you had to have been able to go either A or B, and you, without any prior cause or reason, decided to go, say way B. You had to be responsible for forming your character. At later dates your character might determine what you do, but you are ultimately responsible for who you are.
The last thing I will point out is that Kane has a chapter on how divine foreknowledge and free will are supposed to relate. He explains the problem and the various solutions very well. He didn't spend much time on my solution - the Calvinistic one - and I thought he was too dismissive. I'm not sure he has studied our answers out that much since he didn't provide resources from those I would associate with, viz., Paul Helm, John Frame, etc., in the suggested reading at the end of the chapters (which, by the way, was another excellent bonus in the book. Kane offers a suggested reading list at the end of each chapter so the interested reader can study this debate out more fully.).
If you're looking to get into the metaphysics of free will debate, this is the place to start, bar none. Be careful, though, it's easy to get bit by the free will bug. The debate has been going on between philosophers for thousands of years without any common consensus on the matter, you'll see why.