W alter Lippmann was an influential early twentieth-century scholar, journalist, and political philosopher who wrote prolifically about the relationship among newspapers, public opinion, and the democratic process. Born in 1889, his best-known work, Public
Opinion, was published in 1922. He continued as an active intellectual until his death in 1974. In contrast to many classical writers of earlier years who undertook similar goals, Lippmann used a clear, concise, and very readable writing style. However, his basic ideas are scattered through a huge body of books, articles, and other writings that he produced over more than a half century. This makes it difficult to bring them together into a simple summary. Nevertheless, because his explanations of the relationship among public opinion, the press, and public policy in a democratic system remain so central to understanding those issues today, it is important to try to identify his central set of propositions and set them forth in formal terms as the basic assumptions of his theory. That is specifically the goal of the present chapter.