Jon Barwise

Kenneth Jon Barwise (; June 29, 1942 – March 5, 2000) was an American mathematician, philosopher and logician who proposed some fundamental revisions to the way that logic is understood and used.

Education and career He was born in Independence, Missouri, to Kenneth T. and Evelyn Barwise.

A student of Solomon Feferman at Stanford University, Barwise began his research working in infinitary logic. After positions at Yale University and the University of Wisconsin, during which time his interests turned to natural language, he returned to Stanford in 1983 to direct the Center for the Study of Language and Information (CSLI). He began teaching at Indiana University in 1990. He was elected a Fellow of the American Academy of Arts and Sciences in 1999.

In his final year, Barwise was invited to give the 2000 Gödel Lecture; he died prior to the lecture.

Philosophical and logical work

Barwise contended that, by being explicit about the context in which a proposition is made, the situation, many problems in the application of logic can be eliminated. He sought ... to understand meaning and inference within a general theory of information, one that takes us outside the realm of sentences and relations between sentences of any language, natural or formal. In particular, he claimed that such an approach resolved the liar paradox. He made use of Peter Aczel's non-well-founded set theory in understanding "vicious circles" of reasoning.

Barwise, along with his former colleague at Stanford John Etchemendy, was the author of the popular logic textbook Language, Proof and Logic. The text is notable for including computer-aided homework problems, some of which provide visual representations of logical problems. During his time at Stanford, he was also the first Director of the Symbolic Systems Program, an interdepartmental degree program focusing on the relationships between cognition, language, logic, and computation. The K. Jon Barwise Award for Distinguished Contributions to the Symbolic Systems Program has been given periodically since 2001.

Selected publications Barwise, K. J. (1975) Admissible Sets and Structures. An Approach to Definability Theory Barwise, K. J. & Perry, John (1983) Situations and Attitudes. Cambridge: MIT Press. Barwise, K. J. & Etchemendy, J. (1987) The Liar: An Essay in Truth and Circularity Barwise, K. J. (1988) The Situation in Logic Barwise, K. J. & Moss, L. (1996) Vicious Circles. On the Mathematics of Non-Wellfounded Phenomena Barwise, K, J. & Seligman, J. (1997) Information Flow: the Logic of Distributed Systems Barwise, K. J. & Etchemendy, J. (2002) Language, Proof and Logic Barwise, K. J. Editor (1977) Handbook of Mathematical Logic. xi+1165 pages Barwise, J. & Feferman, S. Editors (1985) Model-Theoretic Logics. x+893 pages