A classic book on propaganda technique proposes a general theory of the strategy and tactics of propaganda. This classic book on propaganda technique focuses on American, British, French, and German experience in World War I. The book sets forth a simple classification of various psychological materials used to produce certain specific results and proposes a general theory of strategy and tactics for the manipulation of these materials. In an introduction (coauthored by Jackson A. Giddens) written for this edition, Harold Lasswell notes that this study was partially an exercise in the discovery of appropriate theory. It raised the crucial questions of how to classify the content of propaganda—for instance, a distinction is made between "value demands" (war aims, war guilt, and casting the enemy as evil personified) and "expectations" (the illusion of victory)—and how to summarize the procedures employed in organizing and carrying out propaganda operations. Propaganda Technique in World War I deals primarily with problems of internal administration and lateral coordination rather than with the relationship between policymakers and propagandists. However, Jackson Giddens enumerates procedures in the book that illustrate an underlying assumption that decision makers were deeply involved in propaganda and influenced by considerations of public opinion. He takes the study of propaganda further by elaborating on the nature and meaning of the category of "war aims" and its relation to the propagandist, for this, more than any other category of content, "is the catalyst of transnational political action." Giddens's exploration of the development of a comprehensive theory of propaganda adds another dimension to Lasswell's study while confirming its value as outstanding groundwork for continuing research.