The article presents a memoir of U.S. legal scholar Thomas Reed Powell. The article author states that although Powell founded no school and espoused no doctrinal creed, his teaching and writing were distinctive, unmistakable, and inimitable. His published papers, numbering close to two hundred essays, are marked by that relentless analysis of judicial rhetoric, that irreverent uncloaking of disreputable logic, that playfulness in the service of intellectual morality, which made him a fearsome delight to students and friends. If one were to revert after all to the language of science and identify a phenomenon with his name, it would have to be called the Powell Effect.