Although the author purports to address the issue of free will from a neuroscience point of view he goes off on many, many tangents and is oddly reticent to make any firm assertions.
He gives a good tour of the current state of what we understand about how the brain works. This is meant to set the stage for addressing the question of whether brain chemistry and wiring pre-determines out decisions or if free will really exists. However, although he asserts that he thinks free will exists he does not create any structured arguments to support his belief. Either he feels the evidence speaks for itself (in which case he has over-estimated his audience) or his hypothesis never crystallized in his mind.
As an experienced neuroscientist he has a masterful grasp of the subject (although I found his frequent, parenthetical comments of "so-and-so, who worked in a lab across campus from me" did not add anything to the story.) Not only does he understand what he is writing about, but he has thought deeply about the implications and he presents the material accurately.
I found the performance to be rather snarky and it distracted from the text.
The survey of current neuroscience makes the book worth reading, but I think he does a disservice to claim the book is about free will.
I found this less compelling than "The Demon Under the Microscope." The discovery is relatively straightforward which requires a lot of "filler" material to flesh out the book.
The science of nitrogen fixation and it's profound implications for humanity quickly draw in the reader but the plot climaxes too quickly. This creates a prolonged denouement chronicling the remainder of Haber and Bosch's lives. It really feels like three separate books--one about nitrogen fixation and two biographies.
The performance is good and the characters are interesting but the science is a bit light. I believe most readers come to a book like this expecting to learn some interesting technical details. He talks about the process, but never drills down to the chemistry.
I would recommend it to anyone interested in the protagonists' lives or science history, but I would recommend "The Demon Under the Microscope" first.