This provocative book refurbishes the traditional account of freedom of will as reasons-guided "agent" causation, situating its account within a general metaphysics. O'Connor's discussion of the general concept of causation and of ontological reductionism v. emergence will specially interest metaphysicians and philosophers of mind.
This may end up being one of the ten most important books I've ever read, but also one of the ten most frustrating.
The theory of agent causation holds that agents are, at least sometimes, capable of making choices whose results are neither fully pre-determined by our already existing nature/nurture nor by purely random or indeterministic external or internal forces outside the will itself. All these things may influence the will, but, O'Connor contends, it is coherent to hold that the will itself acts outside their influence (at least in part). In the most memorable phrase of the book, he suggests that, while we may not be the "unmoved movers" of ancient philosophy, we might be at least "not-wholly-moved movers" (4.1). He offers no proof for this position (and doesn't claim to prove it), but defends its coherence against the wide array of attacks leveled against it throughout the 20th century, and offers several compelling reasons for why we might find it more probable than determinist alternatives.
O'Connor's argument for the coherence of this position is dense, thorough, and brief. Unfortunately, it's not the brief density of vivid clarity. It is the mud-slog density of analytic philosophers talking in shortcuts. For the first third, I thought probably I was just dumb and insufficiently trained to appreciate the writing, but, by the back half, I was pretty sure that (while I am pretty dumb and not nearly well-trained enough) O'Connor's style was making a lot of missteps, too.
The target audience seems to be professional philosophers and graduate philosophy students who are already broadly familiar with not only the full range of analytic tools, but specifically with existing literature on free will. Even for much of that audience, I think it would be a struggle. O'Connor's writing style very rarely slows down to expand on a point with an illustration; he is already on to the next argument. I'm not a philosophy grad student, but neither am I a total n00b; there's an unpublished paper on my hard drive that's just a Thomist sendup of David Lewis's seminal "Holes." Yet I think this is the hardest book I've ever read, including Edward Feser's book on Scholastic Metaphysics and a book I once read on wormhole physics. (I don't know any math.) I think O'Connor is a brilliant thinker but not a great writer. (That's okay; being a brilliant thinker is enough of a blessing for him already, and I'm okay having to work for my meal on occasion.)
Nevertheless, the concept of libertarian free will has always evaded me. Going back to my youth arguing with my parents at the dinner table about religious topics, I've always felt that determinism is not just true, but *obviously* true. *Obviously* moral responsibility is impossible. Reading Derk Pereboom was just an exercise in vigorously nodding along with him. Galen Strawson's Basic Argument seemed unanswerable (no matter how many answers I read in the various journals). Now, with O'Connor's book in hand, I think agent causation is plausible. That's... huge. That's seismic. That could change my whole life. I owe this book a lot, even if I have to read the same page six times every time I pull it off the shelf. I therefore salute the author.
In a sentence: I want to believe there is a magical agent over and above my mental states, so I will just assume that and bend the rules of physics to my will.