This is an important new book about human motivation, about the reasons people have for their actions. What is distinctively new about it is its focus on how people see or understand their situations, options, and prospects. By taking account of people's understandings (along with their beliefs and desires), Professor Schick is able to expand the current theory of decision and action. The author provides a perspective on the topic by outlining its history. He defends his new theory against criticism, considers its formal structure, and shows at length how it resolves many currently debated problems: the problems of conflict and weakness of will, Allais' problem, Kahneman and Tversky's problems, Newcomb's problem, and others. The book will be of special interest to philosophers, psychologists, and economists.