Editing Arthur Prior (section)

==Professional life==
Prior was educated entirely in New Zealand, where he was fortunate to have come under the influence of [[J.&nbsp;N. Findlay]],<ref name=SEP/> under whom he wrote his M.A. thesis on 'The Nature of Logic'.<ref name="David Jakobsen 2019">David Jakobsen (2019): A.N. Prior and ‘The Nature of Logic’, History and Philosophy of Logic, DOI: 10.1080/01445340.2019.1605479</ref> While Prior was very fond of the theology of [[Karl Barth]], his early criticism of Barth's adherence to Philosophical Idealism, is a mark of Findlay's influence on Prior.<ref name="David Jakobsen 2019"/>

He began teaching [[philosophy]] and logic at [[Canterbury University College]] in February 1946, filling the vacancy created by [[Karl Popper]]'s resignation. In 1951 Prior met [[J.&nbsp;J.&nbsp;C. Smart]], also known as "Jack" Smart, at a philosophical conference in Australia and the two developed a life-long friendship. Their correspondence was influential on Prior's development of [[Temporal logic#Prior's tense logic (TL)|tense logic]]. Smart adhered to the tenseless theory of time and was never persuaded by Prior's arguments, though Prior was influential in making Smart skeptical about [[Wittgenstein]]'s view on pseudo-relations.<ref>Jakobsen, D. (2017) The Significance of the Prior-Smart Correspondence for the Rise of Tense-Logic. In: Hasle, P., Blackburn, P. and Øhrstrøm, P.(eds.): Logic and Philosophy of Time: Themes from Prior. Aalborg University Press: pp. 63-82.  ([http://aauforlag.dk/UserFiles/file/Logic_and_Philosophy_of_Themes_from_Prior_ONLINE.pdf ''Logic and Philosophy of Time: Themes from Prior''].</ref> He became Professor in 1953. Thanks to the good offices of [[Gilbert Ryle]], who had met Prior in New Zealand in 1954, Prior spent the year 1956 on leave at the [[University of Oxford]], where he gave the [[John Locke lectures]] in philosophy. These were subsequently published as ''Time and Modality'' (1957). This is a seminal contribution to the study of tense logic and the [[metaphysics]] of time, in which Prior championed the [[A series and B series|A-theorist]] view that the temporal modalities of past, present and future are basic [[ontological]] categories of fundamental importance for our understanding of time and the world. Prior was several times warned by [[J.&nbsp;J.&nbsp;C. Smart]] against making tense-logic the topic of his [[John Locke lectures]]. Smart feared that tense-logic would get Prior "involved in side issues, even straight philosophy, and not in the stuff that will do Oxford most good."<ref>Jakobsen, D. (2017) The Significance of the Prior-Smart Correspondence for the Rise of Tense-Logic. In: Hasle, P., Blackburn, P. and Øhrstrøm, P.(eds.): Logic and Philosophy of Time: Themes from Prior. Aalborg University Press: p 78. aauforlag.dk/UserFiles/file/Logic_and_Philosophy_of_Themes_from_Prior_ONLINE.pdf
</ref> Prior was however convinced that tense-logic had the potential to benefit logic, as well as philosophy, and thus he considered his lectures an "expression of a conviction that formal logic and general philosophy have more to bring to one another than is sometimes supposed".<ref>Prior, A.N., (1957) Time and Modality, Oxford University Press, p. vii</ref>

During his time at Oxford, Prior met [[Peter Geach]] and [[William Kneale]], influenced [[John Lemmon]], and corresponded with the adolescent [[Saul Kripke]]. Logic in the United Kingdom was then in a rather low state, being "deeply out of fashion and its practitioners were isolated and somewhat demoralized."<ref>Copeland, J., (1996) Prior's Life and Legacy, In Logic and Reality, Edited by Copeland, J. Oxford University Press, pp. 6)</ref>  Prior arranged Logical a Colloquium which brought together such Logicians as [[John Lemmon]], [[Peter Geach]], [[Czesław Lejewski]] and more.<ref name="Copeland, J 1996 p. 6">Copeland, J (1996), Prior's Life and Legacy, p. 6.</ref> The colloquiums were a great success and, together with Prior's John Locke lecture and his visits around the country, he helped revitalize British logic.<ref name="Copeland, J 1996 p. 6"/> From 1959 to 1966, he was Professor of Philosophy at the [[University of Manchester]], having taught [[Osmund Lewry]]. From 1966 until his death he was Fellow and Tutor in philosophy at [[Balliol College, Oxford]]. His students include [[Max Cresswell]], [[Kit Fine]], and Robert Bull.

Almost entirely self-taught in modern [[formal logic]], Prior published four major papers on logic in 1952,<ref>{{Citation|last=Copeland|first=B. Jack|title=Arthur Prior|date=2020|url=https://plato.stanford.edu/archives/spr2020/entries/prior/|encyclopedia=The Stanford Encyclopedia of Philosophy|editor-last=Zalta|editor-first=Edward N.|edition=Spring 2020|publisher=Metaphysics Research Lab, Stanford University|access-date=2021-03-09 |quote=Of the four technical papers that marked the explosive beginning of Prior’s career as a formal logician in 1952 (1952a-d), two concerned modal logic...His one recourse in the face of isolation was to read, and read he did. In logic he began by returning to W.E. Johnson. Next came J.N. Keynes’s Studies and Exercises in Formal Logic and then (in his own phrase) he got stuck into Principia Mathematica. He learned a lot about the history of the subject from Peirce, whom he found ‘unexpectedly magnificent’. An important discovery, in 1950, was Bochenski’s Précis de Logique Mathematique (Bochenski 1949). Prior was fascinated by the ‘very neat symbolic notation’ due to Łukasiewicz, and before long he turned his back completely on the more usual Peano-Russell notation}}</ref> when he was 38 years of age, shortly after discovering the work of [[Józef Maria Bocheński]] and [[Jan Łukasiewicz]],<ref>{{Citation|last=Copeland|first=B. Jack|title=Arthur Prior|date=2020|url=https://plato.stanford.edu/archives/spr2020/entries/prior/|encyclopedia=The Stanford Encyclopedia of Philosophy|editor-last=Zalta|editor-first=Edward N.|edition=Spring 2020|publisher=Metaphysics Research Lab, Stanford University|access-date=2021-03-09 |quote=This paper was the curtain raiser to Prior’s extensive study of Łukasiewicz’s work on modality, and thereafter he read Łukasiewicz widely...To judge by his references in The Craft, his first encounters with modern symbolic modal logic must have been the pioneering explorations by Lewis in his and Langford’s Symbolic Logic, Bochenski’s chapter ‘La Logique de la Modalité’ in his La Logique de Théophraste, and Feys’ article ‘Les Systèmes Formalisés des Modalités Aristotéliciennes’...An important discovery, in 1950, was Bochenski’s Précis de Logique Mathematique (Bochenski 1949). Prior was fascinated by the ‘very neat symbolic notation’ due to Łukasiewicz, and before long he turned his back completely on the more usual Peano-Russell notation.}}</ref> despite very little of Łukasiewicz's work being translated into English.<ref name="Copeland 2020">{{Citation|last=Copeland|first=B. Jack|title=Arthur Prior|date=2020|url=https://plato.stanford.edu/archives/spr2020/entries/prior/|encyclopedia=The Stanford Encyclopedia of Philosophy|editor-last=Zalta|editor-first=Edward N.|edition=Spring 2020|publisher=Metaphysics Research Lab, Stanford University|access-date=2021-03-09 |quote=This paper was the curtain raiser to Prior’s extensive study of Łukasiewicz’s work on modality, and thereafter he read Łukasiewicz widely—even material in Polish, saying ‘the symbols are so illuminating that the fact that the text is incomprehensible doesn’t much matter’.}}</ref><ref>{{cite book |last1=Lejewski |first1=C. |editor1-last=Borchert |editor1-first=David |title=Encyclopedia of Philosophy |date=2006 |publisher=Thomas Gale & MacMillan Reference |location=USA |isbn=0028657853 |pages=605–609 |edition=2nd |quote=...It must have stood high in the author's own estimation, for in 1995 he began translating it into English.}}</ref> He went so far as to read untranslated Polish texts without being able to speak Polish claiming "the symbols are so illuminating that the fact that the text is incomprehensible doesn’t much matter".<ref name="Copeland 2020"/> He went on to employ [[Polish notation]] throughout his career.<ref>{{Citation|last=Copeland|first=B. Jack|title=Arthur Prior|date=2020|url=https://plato.stanford.edu/archives/spr2020/entries/prior/|encyclopedia=The Stanford Encyclopedia of Philosophy|editor-last=Zalta|editor-first=Edward N.|edition=Spring 2020|publisher=Metaphysics Research Lab, Stanford University|access-date=2021-03-09 |quote= Prior was fascinated by the ‘very neat symbolic notation’ due to Łukasiewicz, and before long he turned his back completely on the more usual Peano-Russell notation...Formal Logic is steeped in Polish notation and the axiomatic method, and typifies Prior’s mature work.}}</ref> Prior (1955) distills much of his early teaching of logic in New Zealand. Prior's work on tense logic provides a systematic and extended defense of a tensed conception of [[reality]] in which propositional statements can change truth value over time.<ref>{{Citation|last=Copeland|first=B. Jack|title=Arthur Prior|date=2020|url=https://plato.stanford.edu/archives/spr2020/entries/prior/|encyclopedia=The Stanford Encyclopedia of Philosophy|editor-last=Zalta|editor-first=Edward N.|edition=Spring 2020|publisher=Metaphysics Research Lab, Stanford University|access-date=2021-03-09 |quote= This idea that tensed propositions are liable to be true at one time and false at another became central to Prior’s philosophy. In a summary of his views, composed nearly two decades later, he wrote: Certainly there are unchanging truths, but there are changing truths also, and it is a pity if logic ignores these, and leaves it … to comparatively informal ‘dialecticians’ to study the more ‘dynamic’ aspects of reality. (Prior 1996a: 46)}}</ref>

Prior stood out by virtue of his strong interest in the [[history of logic]]. He was one of the first English-speaking logicians to appreciate the nature and scope of the logical work of [[Charles Sanders Peirce]], and the distinction between ''[[de dicto]]'' and ''[[de re]]'' in [[modal logic]]. Prior taught and researched [[modal logic]] before Kripke proposed his [[Kripke semantics|possible worlds semantics]] for it, at a time when modality and intensionality commanded little interest in the English speaking world, and had even come under sharp attack by [[Willard Van Orman Quine]].

He is now said to be the precursor of [[hybrid logic]].<ref name="CarnielliPizzi2008">{{cite book| author1=Walter Carnielli| author2=Claudio Pizzi| title=Modalities and Multimodalities| url=https://books.google.com/books?id=XpAFM04G6BAC&pg=PA181| year=2008| publisher=Springer| isbn=978-1-4020-8589-5| page=181 }}</ref> Undertaking (in one section of his book ''Past, Present, and Future'' (1967)) the attempt to combine binary (e.g., "until") and unary (e.g., "will always be") temporal operators to one system of [[temporal logic]], Prior—as an incidental result—builds a base for later hybrid languages.

His work ''Time and Modality'' explored the use of a [[many-valued logic]] to explain the problem of [[non-referring names]].

Prior's work was both philosophical and formal and provides a productive [[synergy]] between formal innovation and linguistic analysis.{{citation needed|date=November 2012}} [[Natural language]], he remarked, can embody folly and confusion as well as the wisdom of our ancestors. He was scrupulous in setting out the views of his adversaries, and provided many constructive suggestions about the formal development of alternative views.

<blockquote>He possessed an intellectual purity and a devotion to the subject that I immediately recognized and have always attempted to emulate ([[Kit Fine]])<ref>https://www.researchgate.net/publication/375917611_Kit_Fine%27s_Autobiography</ref></blockquote>