This article traces the evolution of Milton Friedman’s ideological views over the course of his adult life. It finds the evolution to be from a moderate liberalism to a definite classical liberalism and then, during the last 50 years of his life, to an increasingly robust libertarianism. Friedman explicitly acknowledged a change in his views on a number of policy issues; also, sometimes even if his opinion on an issue did not change, the strength with which he held and promoted it did. A significant point in Friedman’s life was his retirement and relocation to San Francisco in 1976. There he became almost exclusively a public policy advocate, and his mode of discourse shifted significantly away from empirical demonstration and toward invoking and applying what he considered to be the broad verities and maxims of the outlook he had established for himself.