Richard Allen Posner fundamental concepts.

Richard Allen Posner Concepts

Posner was generally counted as a liberal. However, in reaction to some of the perceived excesses of the late 1960s, Posner developed a strongly conservative bent. He encountered Chicago School economists Aaron Director and George Stigler while a professor at Stanford.[2] Posner summarized his views on law and economics in his 1973 book The Economic Analysis of Law.[2]

Today, although generally viewed as to the right in academia, Posner's pragmatism, his qualified moral relativism and moral skepticism, and his affection for the thought of Friedrich Nietzsche set him apart from most American conservatives. As a judge, Posner's rulings have always placed him on the moderate-to-liberal wing of the Republican Party, where he has become more isolated over time.

In July 2012 Posner stated that "I've become less conservative since the Republican Party started becoming goofy." Among Posner's judicial influences are the American jurists Oliver Wendell Holmes, Jr. and Learned Hand.

Along with Robert Bork, Posner helped shape the antitrust policy changes of the 1970s through his idea that 1960s antitrust laws were in fact making prices higher for the consumer rather than lower, while he viewed lower prices as the essential end goal of any antitrust policy. Posner and Bork's theories on antitrust evolved into the prevailing view in academia and at the Justice Department of the George H. W. Bush Administration.

A 2004 poll by Legal Affairs magazine named Posner as one of the top twenty legal thinkers in the U.S.

In 2008, the University of Chicago Law Review published a commemorative issue: "Commemorating Twenty-five Years of Judge Richard A. Posner." A website, Project Posner, details all of Posner's many legal opinions. It was begun by Posner's former clerk, Tim Wu, who calls Posner "probably America's greatest living jurist."

Another of Posner's former legal clerks, Lawrence Lessig, wrote, "There isn't a federal judge I respect more, both as a judge and person." The former dean of Yale Law School, Anthony T. Kronman, said that Posner was "one of the most rational human beings" he had ever met.

Reference posted in wikipedia
Reference on Legal reasoning 
Becker & Posner blog