From the book: Ivan Karamazov said that if God does not exist everything is permitted, and traditional legal thinkers are likely to say that if legalism (legal formalism, orthodox legal reasoning, a "government of laws not men," the "rule of law" as celebrated in the loftiest "Law Day" rhetoric, and so forth) does not exist everything is permitted to judges--so watch out! Legalism does exist, and so not everything is permitted. But its kingdom has shrunk and greyed to the point where today it is largely limited to routine cases, and so a great deal is permitted to judges. Just how much is permitted and how they use their freedom are the principal concerns of this book. ... I am struck by how unrealistic are the conceptions of the judge held by most people, including practicing lawyers and eminent law professors, who have never been judges--and even by some judges. This unrealism is due to a variety of things, including the different perspectives of the different branches of the legal profession--including also a certain want of imagination. It is also due to the fact that most judges are cagey, even coy, in discussing what they do. They tend to parrot an official line about the judicial process (how rule-bound it is), and often to believe it, though it does not describe their actual practices. This book parts the curtain a bit.

Richard A. Posner retired as a judge of the United States Court of Appeals for the Seventh Circuit in 2017. He was previously a senior lecturer at the University of Chicago Law School.