Thomas Healy’s The Great Dissent re-treads the familiar story of US Supreme Court Justice Holmes’s First Amendment conversion between March and November 1919, when he launched his marketplace of ideas theory and strong-form version of the clear and present danger doctrine. Healy’s book demonstrates that fresh perspectives on this vital and ever-intriguing change of mind or transformation on Holmes’s part remain possible. The review offers its own perspective by highlighting the process of “reverse mentoring” which took place, in which the older jurist was mentored on free speech issues by the emerging thought leaders of the day – Laski, Frankfurter, Chafee – and showing how Justice Holmes’s landmark dissent in Abrams was nonetheless and indisputably a product of his own jurisprudential ingenuity.