The Oxford Companion to Philosophy Part 49. The book is alphabetized by the whole headings of entries, as distinct from the first word of a heading. Hence, for example, abandonment comes before a priori and a posteriori. It is wise to look elsewhere if something seems to be missing. At the end of the book there is also a useful appendix on Logical Symbols as well as the appendices A Chronological Table of Philosophy and Maps of Philosophy. | 460 Jeffrey Richard Jeffrey Richard 1926-2002 . Princeton philosopher. Jeffrey helped develop the subjective interpretation of probability and Bayesian approaches to decision theory and Confirmation. Using relatively simple mathematical and logical machinery he developed materials from Thomas Bayes Frank Ramsey and others into what amounts to a version of the ancient Sceptic Sextus Empiricus dream of solving practical and theoretical problems by appeal to one s own desires preferences and subjective impressions without assuming any objective knowledge. Jeffrey s contributions to the epistemology ofscience include techniques for calculating the probability of a hypothesis from uncertain evidence and investigations of problems raised for confirmation theories by photographs and other such non-propositional evidence. By popularizing the use of truth trees in teaching introductory logic he saved countless thousands of innocent students from incalculable hours of drudgery. . Richard Jeffrey The Logic ofDecision 2nd edn. Chicago 1983 . jen see Confucianism. Jevons William Stanley 1835-82 . British economist and philosopher who taught in Manchester and London. Much of his work was pioneering and influential such as his theory of utility in economics and his inclusive interpretation of the logical connective either . . . or . His logical theory was based on the principle of the substitution of similars the idea that what is true of a thing is true of its like. He recognized that logical deduction is a mechanical process and invented a machine that could perform inferences. However his theory of scientific method developed in The Principles of Science 1874 though more neglected is equally deserving of respect. He opposed Mill s views on induction arguing instead for a hypo-thetico-deductive account ofscience in which theories are not conclusively verified but have a degree of probability interpreted as a measure ofreasonable belief. . Margaret Schabas A World .
