Oliver Wendell Holmes Jr.

Oliver Wendell Holmes Jr. (1841–1935) was an American jurist and legal scholar who served as an Associate Justice of the Supreme Court from 1902 to 1932. The son of the poet Oliver Wendell Holmes Sr., he fought with the 20th Massachusetts Volunteer Infantry in the Civil War, suffering three severe wounds at Ball's Bluff, Antietam, and Chancellorsville, which shaped his lifelong philosophical skepticism and tough-minded legal pragmatism.

In his 1881 masterpiece The Common Law, Holmes declared: 'The life of the law has not been logic: it has been experience'. Appointed to the Supreme Court by Theodore Roosevelt, Holmes became famous as 'The Great Dissenter', defending state economic regulations against substantive due process (Lochner v. New York). In Schenck v. United States (1919), he introduced the 'clear and present danger' doctrine and in Abrams v. United States formulated the iconic concept of the free 'marketplace of ideas'.