William J. McGuire's research on the diverse topics of attitudes, beliefs, self, thought systems, language, history, and methodology created and shaped social psychology in enduring ways. In this collection, his work appears with new commentary and bridging sections that illuminate the context in which the original papers were written. Here, students of psychology and its history can learn about the creative and critical processes that McGuire sought to study: the magical experiments on attitude innoculation showing that small doses of a persuasive message can increase resistance to later larger doses; the construction of self in terms of its distinctive and atypical features; the content, structure, and processing of thought system functioning by balancing logical consistency, realistic coping, and hedonic gratification; persuasion by Socratic questioning that selectively directs attention; and the process of doing research as an exciting and infinitely rewarding activity. These papers not only provide insight into one of psychology's greatest minds, but they also tell the story of psychology's history over the past fifty years. William J. McGuire is Professor of Psychology at Yale University. A Fulbright Scholar and Guggenhiem Fellow, McGuire received the Distinguished Scientific Contribution Award from the American Psychological Association, the Distinguished Scientist Award from the Society of Experimental Social Psychology, and is a William James Fellow of the American Psychological Society.