Nuel Belnap | |
|---|---|
| Born | Nuel Dinsmore Belnap Jr. (1930-05-01)May 1, 1930 |
| Died | June 12, 2024(2024-06-12) (aged 94) |
| Education | |
| Education | University of Illinois Yale University (PhD, 1960)[citation needed] |
| Thesis | The Formalization of Entailment (1960) |
| Doctoral advisor | Alan Ross Anderson |
| Philosophical work | |
| Era | Contemporary philosophy |
| Region | Western philosophy |
| School | Analytic |
| Institutions | University of Pittsburgh |
| Doctoral students | Ruth Manor |
| Main interests | Philosophical logic,temporal logic,structural proof theory |
| Notable ideas | Display logic |
Nuel Dinsmore Belnap Jr. (/ˈbɛlnæp/; May 1, 1930 – June 12, 2024) was an American logician and philosopher who has made contributions to thephilosophy of logic,temporal logic, andstructural proof theory. He taught at theUniversity of Pittsburgh from 1963 until his retirement in 2011.
Belnap was born on May 1, 1930.[1] He attendedNew Trier High School inWinnetka, Illinois, and earned a Bachelor of Arts degree from theUniversity of Illinois.[1] He recalled Max Fisch assignedWhitehead readings.[citation needed]
Belnap worked as a programmer on theIBM 701 for theNational Security Agency through theUnited States Air Force for two years before attending graduate school atYale University.[1] He enjoyedmetaphysics, and his professors includedPaul Weiss,Arthur Pap,Henry Margenau,Frederic Fitch, and Rulon Wells.[citation needed]
On aFulbright Fellowship in 1958 he went toLouvain to study with CanonRobert Feys. Belnap domiciled in Brussels with wife and 2-year-old. Feys directed Belnap to readWilhelm Ackermann's article on rigorous implication in theJournal of Symbolic Logic.[2]
Alan Ross Anderson and Belnap began to discuss relevant implication. In 1960 Anderson told Belnap to write up the work he had done onrelevance logic, and this was Belnap's PhD dissertation at Yale (entitledThe Formalization of Entailment). The dissertation was published through Omar Kayam Moore at Office of Naval Research, Group Psychology Branch.[citation needed]
Belnap became an assistant professor at Yale. He recalled hiringJon Barwise and John Wallace as research assistants.[3]
Pittsburgh University wantedWilfrid Sellars, and according to Belnap, "Jerry Sneewind and I hung on his coattails."Adolf Grunbaum andNicholas Rescher were at Pittsburgh. Vice chancellor Charlie Peake brought Alan Anderson to Pittsburgh in 1965, where he worked until his death in 1973. Anderson and Belnap were co-authors ofEntailment: The Logic of Relevance and Necessity.[4][5] "The way we worked when we worked together was cheek by jaw. We just sat down and wrote sentences together."[3]
Belnap became full professor in 1966.Kurt Baier was department chairman. Belnap began to teach philosophy of social sciences, with students includingBas van Fraassen andJon Michael Dunn. In 1967 he became professor of sociology and in 1971 professor philosophy of science. Eventually he occupied the endowed chair named for Alan Ross Anderson. He recalled Rich Tomason, student of intelligent systems, passing through Pitt.[3]
Wary of consequences of contradictory stored data, Belnap proposed afour-valued logic to avoid run-away inferences such as (A & ~A) →B for an arbitrary statementB.[6] Known as theprinciple of explosion inclassical logic, the four-valued logic provides a basis forparaconsistent logic to avoid this pathology of two-valued logic.
In 1976 Belnap and T. B. Steel Jr. publishedThe Logic of Questions and Answers as a timely contribution toerotetics. Beyondpropositional logic, they noted that the evolvingdatabases make possible "dossier files on individuals" (page 146) leading to the "problem ofprivacy in record keeping." The book included a 45-page annotated bibliography of erotetics, sectioned by philosophy, linguistics, automatic question-answering, and pedagogy, compiled byHubert Schleichert and Urs Egli.
On sabbatical, Belnap was visiting professor at theUniversity of California, Irvine and atIndiana University Bloomington, in the falls of 1977, 1978, 1979 with Jon Michael Dunn. In 1982 atStanford'sCenter for Advanced Studies in the Behavioral Sciences, and in 1996 atLeipzig, Centrum für Höhere Studien with Heirich Wansing. He was a founding member of the Society for Exact Philosophy, which collaborated with Canadians such asMario Bunge. Belnap has served as referee for many academic papers.[3]
He was elected a Fellow of theAmerican Academy of Arts and Sciences in 2008.[7]
Belnap had three sons and a daughter with his first wife, Joan Gohde Belnap.[1] He died inWhitefield, New Hampshire on June 12, 2024, at the age of 94.[1]
