Richard C. Jeffrey (5 August 1926 – 9 November 2002) was an American philosopher, logician, and probability theorist. Events 642 - Battle of Maserfield - Penda of Mercia defeats and kills Oswald of Bernicia. Year 1926 ( MCMXXVI) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar. Events 694 - Egica, a king of the Visigoths of Hispania, accuses Jews of aiding Muslims sentencing all See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. The United States of America —commonly referred to as the Philosophy is the study of general problems concerning matters such as existence knowledge truth beauty justice validity mind and language Logic is the study of the principles of valid demonstration and Inference. Probability theory is the branch of Mathematics concerned with analysis of random phenomena He was a native of Boston, Massachusetts.
Jeffrey served in the U.S. Navy during World War II. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including As a graduate student he studied under Rudolf Carnap, Kurt Gödel, and Carl Hempel. Rudolf Carnap ( May 18, 1891 &ndash September 14, 1970) was an influential German -born philosopher who was active in Kurt Gödel (kʊɐ̯t ˈgøːdl̩ (April 28 1906 – January 14 1978 was an Austrian American Logician, Mathematician and Philosopher Carl Gustav "Peter" Hempel (born January 8 1905 in Oranienburg, Germany died November 9 1997 in Princeton He received his M.A. from the University of Chicago in 1952 and his Ph.D. from Princeton in 1957. A Master of Arts ( Latin: Magister Artium) is a Postgraduate academic Master's degree awarded by universities in a large The University of Chicago is a Private university located principally in the Hyde Park neighborhood of Chicago. "PhD" redirects here for other uses see PhD (disambiguation. 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. The City College of The City University of New York (known more commonly as the City College of New York or simply City College, CCNY, or colloquially as Leland Stanford Junior University, commonly known as Stanford University or simply Stanford, is a private Research university located in The University of Pennsylvania (also known as Penn) is a private University located in Philadelphia, Pennsylvania, USA. Princeton University is a private Coeducational research university located in Princeton, New Jersey. Emeritus (ɨˈmɛrɨtəs is an Adjective that is used in the title of a retired Professor, Bishop or other professional He was also a visiting professor at the University of California, Irvine. The University of California Irvine is a public Coeducational Research university situated in Irvine, California.
As a philosopher, Jeffrey specialized in epistemology and decision theory. Epistemology (from Greek επιστήμη - episteme, "knowledge" + λόγος, " Logos " or theory of knowledge Decision theory in Mathematics and Statistics is concerned with identifying the Values uncertainties and other issues relevant in a given He is perhaps best known for defending and developing the Bayesian approach to probability—specifically, for inventing "Jeffrey conditioning" (which he referred to as "probability kinematics"), a way of modeling the change in the probability of a proposition in light of new evidence. Bayesian probability interprets the concept of Probability as 'a measure of a state of knowledge'. Probability is the likelihood or chance that something is the case or will happen In Logic and Philosophy, proposition refers to either (a the content or Meaning of a meaningful Declarative sentence Evidence in its broadest sense includes anything that is used to determine or demonstrate the Truth of an assertion
Jeffrey also wrote or co-wrote two widely used and influential logic textbooks: Formal Logic: Its Scope and Limits, a basic introduction to logic, and Computability and Logic, a more advanced text dealing with, among other things, the famous negative results of twentieth century logic such as Gödel's incompleteness theorems and Tarski's indefinability theorem. Logic is the study of the principles of valid demonstration and Inference. In Mathematical logic, Gödel's incompleteness theorems, proved by Kurt Gödel in 1931 are two Theorems stating inherent limitations of all but the most Tarski's undefinability theorem, stated and proved by Alfred Tarski in 1936 is an important limitative result in Mathematical logic, the Foundations of mathematics
Jeffrey, who died of lung cancer at the age of 76, was known for his sense of humor, which often came through in his breezy writing style. Lung cancer is a Disease of uncontrolled Cell growth in tissues of the Lung. In the preface of his posthumously published Subjective Probability, he refers to himself as "a fond foolish old fart dying of a surfeit of Pall Malls" (p. Pall Mall Cigarettes are a brand of cigarettes produced by R J xii).