New York: McGraw-Hill Book Company [1965], 1965. First edition. Hardcover. 8vo. [8], ix-xiv, 201, [1] pp. Blue cloth with silver and black lettering on the front board and spine. SEP, "Decision Theory", Katie Steele & H. Stefansson; Princeton University, Department of Philosophy: Past Faculty. Jeffrey is perhaps best known for his work in the Bayesian tradition, exploring the methodological foundations and applications of Bayesianism. In this influential book, Jeffrey develops a theory of subjective expected utility combining two functions, a utility function representing an agent’s desires, and a probability function representing the agent's beliefs. Jeffrey proposes an axiomatization and proves a representation theorem. The book was written during Jeffrey's time as a visitor at the Institute for Advanced Study in Princeton. During this period, Jeffrey met weekly with mathematician Kurt Godel who was quite influential in the writing of this book.