Richard Jeffrey is considered to be one of the most influential philosophers of decision-making in the 20th century. His work is unified by his development of Bayesianism, the view that making up one's mind is a matter of adopting judgmental probabilities. Likewise, he advocated radical probabilism by denying objective probability and abandoning attempts to analyze judgment into a rational and an empirical component.
Jeffrey was born in 1926 in Boston, Massachusetts. He earned his M.A. in Philosophy at the University of Chicago in 1952 and his Ph.D. at Princeton University in 1957. After holding academic positions at City College of New York, Stanford University, and the University of Pennsylvania, he joined the faculty of Princeton University in 1974 and became a professor emeritus there in 1999. He was also a visiting professor at the University of California, Irvine.
His philosophical career is closely connected to the story of 20th century philosophy, and most of his teachers had participated in the development of Logical Positivism in Vienna and Berlin in the twenties and early thirties. He collaborated with Rudolf Carnap at Chicago, with Kurt Gödel at the Institute for Advanced Study, and with Carl Gustav Hempel at Princeton.
Among his many publications are such works as
The Logic of Decision (McGraw Hill 1965), a collection of essays entitled
Probability and the Art of Judgment (Cambridge 1992), and also two textbooks entitled
Formal Logic: Its Scope and Limits (McGraw Hill, first edition 1967) and
Computability and Logic, with G. Boolos (first published in 1974).
Richard Jeffrey passed away on November 9, 2002.