Stephen Hawking's The Grand Design is an inspiring masterpiece that is one of my favorite books.
I've found, however, one inconsistency in the book:
1) While conceding that human behavior is indeed determined by the laws of nature, it also seems reasonable to conclude that the outcome is determined in such a complicated way and with so many variables as to make it impossible in practice to predict. For that one would need a knowledge of the initial state of each of the thousand trillion trillion molecules in the human body and to solve something like that number of equations. That would take a few billion years, which would be a bit late to duck when the person opposite aimed a blow. (Chapter 2 THE RULE OF LAW)
We cannot even solve exactly the equations for three or more particles interacting with each other. Since an alien the size of a human would contain about a thousand trillion trillion particles even if the alien were a robot, it would be impossible to solve the equations and predict what it would do. We would therefore have to say that any complex being has free will-not as a fundamental feature, but as an effective theory, an admission of our inability to do the calculations that would enable us to predict its actions.
(Chapter 8 THE GRAND DESIGN)
The above shows us:
Chapter 2 tells us that the human body contains "the thousand trillion trillion molecules," while Chapter 8 tells us "the size of a human would contain about a thousand trillion trillion particles." Yet we know that a molecule contains a lot of particles. So Chapter 2 is not consistent with Chapter 8.