Judge Richard A. Posner of the 7th U.S. Circuit Court of Appeals in 2014. Posner announced he was retiring on Friday afternoon. — Michael R. Schmidt

Richard A. Posner, one of the best known appellate judges in the nation, is retiring from the 7th U.S. Circuit Court of Appeals on Saturday.



Posner, a teacher and a prolific writer on and off the bench, has served on the Chicago-based 7th Circuit for nearly 36 years.



“I am proud to have promoted a pragmatic approach to judging during my time on the Court, and to have had the opportunity to apply my view that judicial opinions should be easy to understand and that judges should focus on the right and wrong in every case,” Posner said in a statement.



“I look forward to continuing to teach and publish, with a particular focus on social justice reform.”



A leading proponent of the law-and-economics school of thought, Posner was widely regarded as a conservative when he was appointed to the bench in 1981 by President Ronald Reagan.



He called for fewer restrictions on domestic surveillance, wrote the majority opinion declaring an Illinois ban on carrying weapons in public to be unconstitutional and dissented from a decision striking down an Illinois law that barred citizens from audio-recording police in public.



But Posner also supported the legalization of marijuana and wrote opinions in favor of abortion rights and same-sex marriage.



While one of the most — if not the most — frequently cited federal appellate judges in the United States, Posner had no interest in serving on the U.S. Supreme Court.



“It’s not a real court,” Posner said in a 2014 interview with the Daily Law Bulletin. “It’s a political court.”



In addition to writing more than 3,300 opinions, Posner has written a slew of books and articles on a wide range of topics, including adoption, domestic intelligence, public intellectuals, President Bill Clinton’s affair with Monica Lewinsky and the ballot recount in the 2000 presidential election.



Posner also pitched in for his colleagues on the U.S. District Court, serving as a trial judge in criminal and civil cases.



Chief Judge Diane P. Wood of the 7th Circuit described Posner’s impact on the court as “immeasurable.”



“For more than 50 years, Judge Posner has been one of the leading public intellectuals in the United States — indeed, in the world,” Wood said in a statement. “He is one of the most distinguished people to ever sit on the federal bench.



“His opinions have had an impact around the world. He has produced an unparalleled body of scholarship — books, articles, and public commentary — covering virtually every legal topic that can be imagined.”



Posner, 78, earned a bachelor’s degree in English at Yale University in 1959 and then graduated from Harvard Law School in 1962.



He clerked for U.S. Supreme Court Judge William J. Brennan Jr. for a year before joining the Federal Trade Commission as assistant to Commissioner Philip Elman.



In 1965, Posner became the assistant to Thurgood Marshall, the future Supreme Court justice who was then the U.S. solicitor general. Two years later, Posner took a job as general counsel to a presidential task force on telecommunications policy.



Posner taught law at Stanford University from 1968 to 1969. He started teaching at the University of Chicago Law School in 1969, first full-time and later part-time.



In 1977, Posner helped found Lexecon Inc., an economic consulting firm that merged in 2008 with Competition Policy Associates. He cut ties with Lexecon after joining the 7th Circuit.



Posner served as the appeals court’s chief judge from 1993 to 2000.