Joseph Schumpeter was not a member of the Austrian School, but he was an enormously creative classical liberal, and this 1919 book shows him at his best. He presents a theory of how states become empires and applies his insight to explaining many historical episodes. His account of the foreign policy of the Roman Empire reads like a critique of the United States today. The second essay examines class mobility and political dynamics within a capitalistic society. Overall, Imperialism and Social Classes is a very important contribution to the literature of political economy.