U.S. law is in the midst of an intellectual revolution. Supreme Court Justice Oliver Wendell Holmes saw it coming more than a century ago: “For the rational study of the law the blackletter man [who focuses on existing legal rules] may be the man of the present, but the man of the future is the man of statistics and the master of economics.”
Holmes’s future is our present. Today’s law school casebooks highlight opinions that display new patterns of legal argument based on economics and statistics as well as psychology and other social sciences. These pathbreaking decisions are written by judges of different political persuasions — liberals such as Stephen Breyer and Guido Calabresi and conservatives such as Frank Easterbrook and Richard Posner. They do not represent a passing political fad but are a central tendency of modern law.