William Rathbone Greg's name is well known to historians of nineteenth-century Britain, but the content of his political thought is not. This article, based on a comprehensive reading of Greg's prolific published output, has two aims. The first is to pin down his politics. The article positions Greg as a leading spokesman for the rationalistic, antidemocratic strand of mid-Victorian Liberalism. It argues that his thought centered on the idea that politics was a science, and that scientific statesmanship might solve many of the problems of the age. The article's second aim is to show that Greg was a sophisticated thinker on politics overseas. He developed distinctive arguments about the structures of European politics, and especially about France under the Second Empire (1852–70). Greg's writings cast important light on the connections between abstract, domestic, and European issues in less familiar reaches of Liberal thought, and on how Victorian political science grappled with Continental despotism.