Seems related to the question of what is consciousness, another issue that I think is more in the religious or philosophical realm rather than the scientific.
I know there is a dedicated section on free will in the book Behave.
I havent read every one, so maybe you are talking about what that I havent seen. From my understanding, his academic career and body of literature largely runs through the how genetic environmental factors impact neurochemistry, and uses this to explain why individual actors behave a certainty way.