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{{short description|American mathematician}}
{{Short description|Polish–American mathematician (1901–1983)}}
{{Infobox scientist
{{Infobox scientist
| birth_name = Alfred Teitelbaum
| birth_name = Alfred Teitelbaum
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}}
}}
| notable_students = [[Evert Willem Beth]]
| notable_students = [[Evert Willem Beth]]
| influences = {{plainlist|
* [[Charles Sanders Peirce]]
* [[Jan Łukasiewicz]]
}}
| influenced = {{plainlist|
* [[Kenneth Arrow]]
* [[Rudolf Carnap]]
* [[John Corcoran (logician)|John Corcoran]]
* [[Donald Davidson (philosopher)|Donald Davidson]]
* [[Erich Leo Lehmann]]
* [[Karl Popper]]
* [[Willard Van Orman Quine]]
* [[Patrick Suppes]]
}}
| known_for = {{plainlist|
| known_for = {{plainlist|
* Work on the foundations of modern [[logic]]
* Work on the foundations of modern [[logic]]
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* [[Finitary relation|Logic of relations]]
* [[Finitary relation|Logic of relations]]
* [[Banach–Tarski paradox]]
* [[Banach–Tarski paradox]]
* [[Tarski's fixed-point theorem]]
* [[Tarski-style universes]]
* [[Tarski-style universes]]
* [[Tarski's axioms]]
* [[Tarski's axioms]]
* [[Tarski monster group]]
* [[Tarski monster group]]
* [[Tarski's circle-squaring problem]]
* [[Tarski–Kuratowski algorithm]]
* [[Jónsson–Tarski duality]]
* [[Jónsson–Tarski duality]]
* [[Lindenbaum–Tarski algebra]]
* [[Tarski's circle-squaring problem]]
}}
}}
}}
}}


'''Alfred Tarski''' ({{IPAc-en|ˈ|t|ɑr|s|k|i}}, born '''Alfred Teitelbaum''';<ref>Alfred Tarski, [https://www.britannica.com/biography/Alfred-Tarski "Alfred Tarski"], ''Encyclopædia Britannica''.</ref><ref name="Alfred Tarski">School of Mathematics and Statistics, University of St Andrews, [http://www-history.mcs.st-and.ac.uk/Biographies/Tarski.html "Alfred Tarski"], ''School of Mathematics and Statistics, University of St Andrews''.</ref><ref name="oxfordreference.com">{{Cite journal | url=http://www.oxfordreference.com/view/10.1093/oi/authority.20110803102144812 | title=Alfred Tarski - Oxford Reference}}</ref> January 14, 1901 &ndash; October 26, 1983) was a Polish-American<ref>{{cite web |url=http://www.oxfordbibliographies.com/view/document/obo-9780195396577/obo-9780195396577-0186.xml |title=Alfred Tarski - Philosophy - Oxford Bibliographies |last=Gomez-Torrente |first=Mario |date=March 27, 2014 |website=[[Oxford University Press]] |access-date=October 24, 2017}}</ref> [[logic]]ian and [[mathematician]].<ref>Alfred Tarski, [https://plato.stanford.edu/entries/tarski/ "Alfred Tarski"], ''Stanford Encyclopedia of Philosophy''.</ref> A prolific author best known for his work on [[model theory]], [[metamathematics]], and [[algebraic logic]], he also contributed to [[abstract algebra]], [[topology]], [[geometry]], [[measure theory]], [[mathematical logic]], [[set theory]], and [[analytic philosophy]].
'''Alfred Tarski''' ({{IPAc-en|ˈ|t|ɑr|s|k|i}}, born '''Alfred Teitelbaum''';<ref>Alfred Tarski, [https://www.britannica.com/biography/Alfred-Tarski "Alfred Tarski"], ''Encyclopædia Britannica''.</ref><ref name="Alfred Tarski">School of Mathematics and Statistics, University of St Andrews, [http://www-history.mcs.st-and.ac.uk/Biographies/Tarski.html "Alfred Tarski"], ''School of Mathematics and Statistics, University of St Andrews''.</ref><ref name="oxfordreference.com">{{Cite encyclopedia | url=http://www.oxfordreference.com/view/10.1093/oi/authority.20110803102144812 | title=Alfred Tarski |encyclopedia=Oxford Reference}}</ref> January 14, 1901 &ndash; October 26, 1983) was a Polish-American<ref>{{cite web |url=http://www.oxfordbibliographies.com/view/document/obo-9780195396577/obo-9780195396577-0186.xml |title=Alfred Tarski - Philosophy - Oxford Bibliographies |last=Gomez-Torrente |first=Mario |date=March 27, 2014 |website=[[Oxford University Press]] |access-date=October 24, 2017}}</ref> [[logic]]ian and [[mathematician]].<ref>Alfred Tarski, [https://plato.stanford.edu/entries/tarski/ "Alfred Tarski"], ''Stanford Encyclopedia of Philosophy''.</ref> A prolific author best known for his work on [[model theory]], [[metamathematics]], and [[algebraic logic]], he also contributed to [[abstract algebra]], [[topology]], [[geometry]], [[measure theory]], [[mathematical logic]], [[set theory]], and [[analytic philosophy]].


Educated in Poland at the [[University of Warsaw]], and a member of the [[Lwów–Warsaw school|Lwów–Warsaw school of logic]] and the [[Warsaw school of mathematics]], he immigrated to the United States in 1939 where he became a naturalized citizen in 1945. Tarski taught and carried out research in mathematics at the [[University of California, Berkeley]], from 1942 until his death in 1983.<ref name=FefA>[[#FefA|Feferman A.]]</ref>
Educated in Poland at the [[University of Warsaw]], and a member of the [[Lwów–Warsaw school|Lwów–Warsaw school of logic]] and the [[Warsaw school of mathematics]], he immigrated to the United States in 1939 where he became a naturalized citizen in 1945. Tarski taught and carried out research in mathematics at the [[University of California, Berkeley]], from 1942 until his death in 1983.<ref name=FefA>[[#FefA|Feferman A.]]</ref>
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Alfred Tarski was born Alfred Teitelbaum ([[Polish language|Polish]] spelling: "Tajtelbaum"), to parents who were [[Polish Jews]] in comfortable circumstances. He first manifested his mathematical abilities while in secondary school, at Warsaw's ''[[Szkoła Mazowiecka]]''.<ref>[[#F-F|Feferman & Feferman]], pp.17-18</ref> Nevertheless, he entered the [[University of Warsaw]] in 1918 intending to study [[biology]].<ref name="Feferman & Feferman, p.26">[[#F-F|Feferman & Feferman]], p.26</ref>
Alfred Tarski was born Alfred Teitelbaum ([[Polish language|Polish]] spelling: "Tajtelbaum"), to parents who were [[Polish Jews]] in comfortable circumstances. He first manifested his mathematical abilities while in secondary school, at Warsaw's ''[[Szkoła Mazowiecka]]''.<ref>[[#F-F|Feferman & Feferman]], pp.17-18</ref> Nevertheless, he entered the [[University of Warsaw]] in 1918 intending to study [[biology]].<ref name="Feferman & Feferman, p.26">[[#F-F|Feferman & Feferman]], p.26</ref>


After Poland regained independence in 1918, Warsaw University came under the leadership of [[Jan Łukasiewicz]], [[Stanisław Leśniewski]] and [[Wacław Sierpiński]] and quickly became a world-leading research institution in logic, [[foundational mathematics]], and the philosophy of mathematics. Leśniewski recognized Tarski's potential as a mathematician and encouraged him to abandon biology.<ref name="Feferman & Feferman, p.26"/> Henceforth Tarski attended courses taught by Łukasiewicz, Sierpiński, [[Stefan Mazurkiewicz]] and [[Tadeusz Kotarbiński]], and in 1924 became the only person ever to complete a doctorate under Leśniewski's supervision. His thesis was entitled ''O wyrazie pierwotnym logistyki'' (''On the Primitive Term of Logistic''; published 1923). Tarski and Leśniewski soon grew cool to each other{{why?}}. However, in later life, Tarski reserved his warmest praise for Kotarbiński, which was reciprocated.
After Poland regained independence in 1918, Warsaw University came under the leadership of [[Jan Łukasiewicz]], [[Stanisław Leśniewski]] and [[Wacław Sierpiński]] and quickly became a world-leading research institution in logic, [[foundational mathematics]], and the philosophy of mathematics. Leśniewski recognized Tarski's potential as a mathematician and encouraged him to abandon biology.<ref name="Feferman & Feferman, p.26"/> Henceforth Tarski attended courses taught by Łukasiewicz, Sierpiński, [[Stefan Mazurkiewicz]] and [[Tadeusz Kotarbiński]], and in 1924 became the only person ever to complete a doctorate under Leśniewski's supervision. His thesis was entitled ''O wyrazie pierwotnym logistyki'' (''On the Primitive Term of Logistic''; published 1923). Tarski and Leśniewski soon grew cool to each other, mainly due to the latter's increasing anti-semitism.<ref name="FFintro" /> However, in later life, Tarski reserved his warmest praise for Kotarbiński, which was reciprocated.


In 1923, Alfred Teitelbaum and his brother Wacław changed their surname to "Tarski". The Tarski brothers also converted to [[Roman Catholicism]], Poland's dominant religion. Alfred did so even though he was an avowed [[atheism|atheist]].<ref>[[#F-F|Feferman & Feferman]], p.294</ref><ref>"Most of the Socialist Party members were also in favor of assimilation, and Tarski's political allegiance was socialist at the time. So, along with its being a practical move, becoming more Polish than Jewish was an ideological statement and was approved by many, though not all, of his colleagues. As to why Tarski, a professed atheist, converted, that just came with the territory and was part of the package: if you were going to be Polish then you had to say you were Catholic." Anita Burdman Feferman, Solomon Feferman, ''Alfred Tarski: Life and Logic'' (2004), page 39.</ref>
In 1923, Alfred Teitelbaum and his brother Wacław changed their surname to "Tarski". The Tarski brothers also converted to [[Roman Catholicism]], Poland's dominant religion. Alfred did so even though he was an avowed [[atheism|atheist]].<ref>[[#F-F|Feferman & Feferman]], p.294</ref><ref>"Most of the Socialist Party members were also in favor of assimilation, and Tarski's political allegiance was socialist at the time. So, along with its being a practical move, becoming more Polish than Jewish was an ideological statement and was approved by many, though not all, of his colleagues. As to why Tarski, a professed atheist, converted, that just came with the territory and was part of the package: if you were going to be Polish then you had to say you were Catholic." Anita Burdman Feferman, Solomon Feferman, ''Alfred Tarski: Life and Logic'' (2004), page 39.</ref>


===Career===
===Career===
After becoming the youngest person ever to complete a doctorate at Warsaw University, Tarski taught logic at the Polish Pedagogical Institute, mathematics and logic at the university, and served as Łukasiewicz's assistant. Because these positions were poorly paid, Tarski also taught mathematics at a Warsaw secondary school;<ref>{{cite web|url=http://www.januszkorczak.ca/bulletins/Bulletin%20%235.pdf|title=The Newsletter of the Janusz Korczak Association of Canada|id=Number 5|date=September 2007|access-date=8 February 2012}}</ref> before World War II, it was not uncommon for European intellectuals of research caliber to teach high school. Hence between 1923 and his departure for the United States in 1939, Tarski not only wrote several textbooks and many papers, a number of them ground-breaking, but also did so while supporting himself primarily by teaching high-school mathematics. In 1929 Tarski married fellow teacher Maria Witkowska, a Pole of Catholic background. She had worked as a courier for the army in the [[Polish–Soviet War]]. They had two children; a son [[Jan Tarski,]] who became a physicist, and a daughter Ina, who married the mathematician [[Andrzej Ehrenfeucht]].<ref>Feferman & Feferman (2004), pp. 239–242.</ref>
After becoming the youngest person ever to complete a doctorate at Warsaw University, Tarski taught logic at the Polish Pedagogical Institute, mathematics and logic at the university, and served as Łukasiewicz's assistant. Because these positions were poorly paid, Tarski also taught mathematics at the Third Boys’ Gimnazjum of the Trade Union of Polish Secondary-School Teachers (later the Stefan Żeromski Gimnazjum), a Warsaw secondary school, beginning in 1925.<ref>{{cite book
| last1 = McFarland | first1 = Andrew
| last2 = McFarland | first2 = Joanna
| last3 = Smith | first3 = James T.
| isbn = 978-1-4939-1473-9
| mr = 3307383
| page = 173
| publisher = Birkhäuser/Springer, New York
| title = Alfred Tarski: Early work in Poland — geometry and teaching
| year = 2014}}</ref> Before World War II, it was not uncommon for European intellectuals of research caliber to teach high school. Hence until his departure for the United States in 1939, Tarski not only wrote several textbooks and many papers, a number of them ground-breaking, but also did so while supporting himself primarily by teaching high-school mathematics.{{sfn|McFarland|McFarland|Smith|2014|p=319}} In 1929 Tarski married fellow teacher Maria Witkowska, a Pole of Catholic background. She had worked as a courier for the army in the [[Polish–Soviet War]]. They had two children; a son [[Jan Tarski,]] who became a physicist, and a daughter Ina, who married the mathematician [[Andrzej Ehrenfeucht]].<ref>Feferman & Feferman (2004), pp. 239–242.</ref>


Tarski applied for a chair of philosophy at [[Lwów University]], but on [[Bertrand Russell]]'s recommendation it was awarded to [[Leon Chwistek]].<ref>[[#F-F|Feferman & Feferman]], p. 67</ref> In 1930, Tarski visited the [[University of Vienna]], lectured to [[Karl Menger]]'s colloquium, and met [[Kurt Gödel]]. Thanks to a fellowship, he was able to return to Vienna during the first half of 1935 to work with Menger's research group. From Vienna he traveled to Paris to present his ideas on truth at the first meeting of the [[Unity of Science]] movement, an outgrowth of the [[Vienna Circle]]. In 1937, Tarski applied for a chair at [[Poznań University]] but the chair was abolished{{why?}}.<ref>[[#F-F|Feferman & Feferman]], pp. 102-103</ref> Tarski's ties to the Unity of Science movement likely saved his life, because they resulted in his being invited to address the Unity of Science Congress held in September 1939 at [[Harvard University]]. Thus he left Poland in August 1939, on the last ship to sail from Poland for the United States before the German and Soviet [[invasion of Poland]] and the outbreak of [[World War II]]. Tarski left reluctantly, because Leśniewski had died a few months before, creating a vacancy which Tarski hoped to fill. Oblivious to the [[Nazi]] threat, he left his wife and children in Warsaw. He did not see them again until 1946. During the war, nearly all his Jewish extended family were murdered at the hands of the German occupying authorities.
Tarski applied for a chair of philosophy at [[Lwów University]], but on [[Bertrand Russell]]'s recommendation it was awarded to [[Leon Chwistek]].<ref>[[#F-F|Feferman & Feferman]], p. 67</ref> In 1930, Tarski visited the [[University of Vienna]], lectured to [[Karl Menger]]'s colloquium, and met [[Kurt Gödel]]. Thanks to a fellowship, he was able to return to Vienna during the first half of 1935 to work with Menger's research group. From Vienna he traveled to Paris to present his ideas on truth at the first meeting of the [[Unity of Science]] movement, an outgrowth of the [[Vienna Circle]]. Tarski's academic career in Poland was strongly and repeatedly impacted by his heritage. For example, in 1937, Tarski applied for a chair at [[Poznań University]] but the chair was abolished to avoid assigning it to Tarski (who was undisputedly the strongest applicant) because he was a Jew.<ref>[[#F-F|Feferman & Feferman]], pp. 102-103</ref> Tarski's ties to the Unity of Science movement likely saved his life, because they resulted in his being invited to address the Unity of Science Congress held in September 1939 at [[Harvard University]]. Thus he left Poland in August 1939, on the last ship to sail from Poland for the United States before the German and Soviet [[invasion of Poland]] and the outbreak of [[World War II]]. Tarski left reluctantly, because Leśniewski had died a few months before, creating a vacancy which Tarski hoped to fill. Oblivious to the [[Nazi]] threat, he left his wife and children in Warsaw. He did not see them again until 1946. During the war, nearly all his Jewish extended family were murdered at the hands of the German occupying authorities.


Once in the United States, Tarski held a number of temporary teaching and research positions: Harvard University (1939), [[City College of New York]] (1940), and thanks to a [[Guggenheim Fellowship]], the [[Institute for Advanced Study]] in [[Princeton, New Jersey|Princeton]] (1942), where he again met Gödel. In 1942, Tarski joined the Mathematics Department at the [[University of California, Berkeley]], where he spent the rest of his career. Tarski became an American citizen in 1945.<ref>[[#F-F|Feferman & Feferman]], Chap. 5, pp. 124-149</ref> Although emeritus from 1968, he taught until 1973 and supervised Ph.D. candidates until his death.<ref>{{cite web|url=http://content.cdlib.org/xtf/view?docId=hb4d5nb20m&doc.view=frames&chunk.id=div00159&toc.depth=1&toc.id=|title=Alfred Tarski, Mathematics: Berkeley|author1=Robert Vaught|author2=John Addison|author3=Benson Mates|author4=Julia Robinson |year=1985|publisher=University of California (System) Academic Senate|access-date=2008-12-26}}</ref> At Berkeley, Tarski acquired a reputation as an astounding and demanding teacher, a fact noted by many observers:
Once in the United States, Tarski held a number of temporary teaching and research positions: Harvard University (1939), [[City College of New York]] (1940), and thanks to a [[Guggenheim Fellowship]], the [[Institute for Advanced Study]] in [[Princeton, New Jersey|Princeton]] (1942), where he again met Gödel. In 1942, Tarski joined the Mathematics Department at the [[University of California, Berkeley]], where he spent the rest of his career. Tarski became an American citizen in 1945.<ref>[[#F-F|Feferman & Feferman]], Chap. 5, pp. 124-149</ref> Although emeritus from 1968, he taught until 1973 and supervised Ph.D. candidates until his death.<ref>{{cite web|url=http://content.cdlib.org/xtf/view?docId=hb4d5nb20m&doc.view=frames&chunk.id=div00159&toc.depth=1&toc.id=|title=Alfred Tarski, Mathematics: Berkeley|author1=Robert Vaught|author2=John Addison|author3=Benson Mates|author4=Julia Robinson |year=1985|publisher=University of California (System) Academic Senate|access-date=2008-12-26}}</ref> At Berkeley, Tarski acquired a reputation as an astounding and demanding teacher, a fact noted by many observers:
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{{blockquote|A charismatic leader and teacher, known for his brilliantly precise yet suspenseful expository style, Tarski had intimidatingly high standards for students, but at the same time he could be very encouraging, and particularly so to women — in contrast to the general trend. Some students were frightened away, but a circle of disciples remained, many of whom became world-renowned leaders in the field.<ref>[[#Fef|Feferman]]</ref>}}
{{blockquote|A charismatic leader and teacher, known for his brilliantly precise yet suspenseful expository style, Tarski had intimidatingly high standards for students, but at the same time he could be very encouraging, and particularly so to women — in contrast to the general trend. Some students were frightened away, but a circle of disciples remained, many of whom became world-renowned leaders in the field.<ref>[[#Fef|Feferman]]</ref>}}
[[File:20070206 uw buw hall glowny biblioteki.jpg|thumb|upright=1.5|[[Warsaw University Library]] – at entrance (seen from rear) are pillared statues of [[Lviv-Warsaw School of Logic|Lwów-Warsaw School]] philosophers (''right to left'') [[Kazimierz Twardowski]], [[Jan Łukasiewicz]], Alfred Tarski, [[Stanisław Leśniewski]].]]
[[File:20070206 uw buw hall glowny biblioteki.jpg|thumb|upright=1.5|[[Warsaw University Library]] – at entrance (seen from rear) are pillared statues of [[Lviv-Warsaw School of Logic|Lwów-Warsaw School]] philosophers (''right to left'') [[Kazimierz Twardowski]], [[Jan Łukasiewicz]], Alfred Tarski, [[Stanisław Leśniewski]].]]
Tarski supervised twenty-four Ph.D. dissertations including (in chronological order) those of [[Andrzej Mostowski]], [[Bjarni Jónsson]], [[Julia Robinson]], [[Robert Vaught]], [[Solomon Feferman]], [[Richard Montague]], [[James Donald Monk]], [[Haim Gaifman]], [[Donald Pigozzi]], and [[Roger Maddux]], as well as [[Chen Chung Chang]] and [[Jerome Keisler]], authors of ''Model Theory'' (1973),<ref>Chang, C.C., and Keisler, H.J., 1973. ''Model Theory''. North-Holland, Amsterdam. American Elsevier, New York.</ref> a classic text in the field.<ref>{{MathGenealogy|id=13347}}</ref><ref name=studentlist>[[#F-F|Feferman & Feferman]], pp. 385-386</ref> He also strongly influenced the dissertations of [[Alfred Lindenbaum]], [[Dana Scott]], and [[Steven Givant]]. Five of Tarski's students were women, a remarkable fact given that men represented an overwhelming majority of graduate students at the time.<ref name=studentlist/> However, he had extra-marital affairs with at least two of these students. After he showed another of his female students{{who?}}' work to a male colleague{{who?}}, the colleague published it himself, leading her to leave the graduate study and later move to a different university and a different advisor.<ref>[[#F-F|Feferman & Feferman]], pp. 177–178 and 197–201.</ref>
Tarski supervised twenty-four Ph.D. dissertations including (in chronological order) those of [[Andrzej Mostowski]], [[Bjarni Jónsson]], [[Julia Robinson]], [[Robert Vaught]], [[Solomon Feferman]], [[Richard Montague]], [[James Donald Monk]], [[Haim Gaifman]], [[Donald Pigozzi]], and [[Roger Maddux]], as well as [[Chen Chung Chang]] and [[Jerome Keisler]], authors of ''Model Theory'' (1973),<ref>Chang, C.C., and Keisler, H.J., 1973. ''Model Theory''. North-Holland, Amsterdam. American Elsevier, New York.</ref> a classic text in the field.<ref>{{MathGenealogy|id=13347}}</ref><ref name=studentlist>[[#F-F|Feferman & Feferman]], pp. 385-386</ref> He also strongly influenced the dissertations of [[Adolf Lindenbaum]], [[Dana Scott]], and [[Steven Givant]]. Five of Tarski's students were women, a remarkable fact given that men represented an overwhelming majority of graduate students at the time.<ref name=studentlist/> However, he had extra-marital affairs with at least two of these students. After he showed another of his female student's{{who|date=July 2023}} work to a male colleague{{who|date=July 2023}}, the colleague published it himself, leading her to leave the graduate study and later move to a different university and a different advisor.<ref>[[#F-F|Feferman & Feferman]], pp. 177–178 and 197–201.</ref>


Tarski lectured at [[University College, London]] (1950, 1966), the [[Institut Henri Poincaré]] in Paris (1955), the [[Miller Institute for Basic Research in Science]] in Berkeley (1958&ndash;60), the [[University of California at Los Angeles]] (1967), and the [[Pontifical Catholic University of Chile]] (1974&ndash;75). Among many distinctions garnered over the course of his career, Tarski was elected to the [[United States National Academy of Sciences]], the [[British Academy]] and the [[Royal Netherlands Academy of Arts and Sciences]] in 1958,<ref>{{cite web|url=http://www.dwc.knaw.nl/biografie/pmknaw/?pagetype=authorDetail&aId=PE00003268 |title=Alfred Tarski (1902 - 1983) |publisher=Royal Netherlands Academy of Arts and Sciences |access-date=17 July 2015}}</ref> received [[honorary degree]]s from the Pontifical Catholic University of Chile in 1975, from [[Marseilles]]' [[Paul Cézanne University]] in 1977 and from the [[University of Calgary]], as well as the Berkeley Citation in 1981. Tarski presided over the [[Association for Symbolic Logic]], 1944&ndash;46, and the International Union for the History and Philosophy of Science, 1956&ndash;57. He was also an honorary editor of ''[[Algebra Universalis]]''.<ref>{{MacTutor Biography|id=Tarski}}</ref>
Tarski lectured at [[University College, London]] (1950, 1966), the [[Institut Henri Poincaré]] in Paris (1955), the [[Miller Institute for Basic Research in Science]] in Berkeley (1958&ndash;60), the [[University of California at Los Angeles]] (1967), and the [[Pontifical Catholic University of Chile]] (1974&ndash;75). Among many distinctions garnered over the course of his career, Tarski was elected to the [[United States National Academy of Sciences]], the [[British Academy]] and the [[Royal Netherlands Academy of Arts and Sciences]] in 1958,<ref>{{cite web|url=http://www.dwc.knaw.nl/biografie/pmknaw/?pagetype=authorDetail&aId=PE00003268 |title=Alfred Tarski (1902 - 1983) |publisher=Royal Netherlands Academy of Arts and Sciences |access-date=17 July 2015}}</ref> received [[honorary degree]]s from the Pontifical Catholic University of Chile in 1975, from [[Marseilles]]' [[Paul Cézanne University]] in 1977 and from the [[University of Calgary]], as well as the Berkeley Citation in 1981. Tarski presided over the [[Association for Symbolic Logic]], 1944&ndash;46, and the International Union for the History and Philosophy of Science, 1956&ndash;57. He was also an honorary editor of ''[[Algebra Universalis]]''.<ref>{{MacTutor Biography|id=Tarski}}</ref>
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In ''A decision method for elementary algebra and geometry'', Tarski showed, by the method of [[quantifier elimination]], that the [[first-order theory]] of the [[real number]]s under addition and multiplication is [[Decidability (logic)|decidable]]. (While this result appeared only in 1948, it dates back to 1930 and was mentioned in Tarski (1931).) This is a very curious result, because [[Alonzo Church]] proved in 1936 that [[Peano arithmetic]] (the theory of [[natural number]]s) is ''not'' decidable. Peano arithmetic is also incomplete by [[Gödel's incompleteness theorem]]. In his 1953 ''Undecidable theories'', Tarski et al. showed that many mathematical systems, including [[lattice theory]], abstract [[projective geometry]], and [[closure algebra]]s, are all undecidable. The theory of [[Abelian group]]s is decidable, but that of non-Abelian groups is not.
In ''A decision method for elementary algebra and geometry'', Tarski showed, by the method of [[quantifier elimination]], that the [[first-order theory]] of the [[real number]]s under addition and multiplication is [[Decidability (logic)|decidable]]. (While this result appeared only in 1948, it dates back to 1930 and was mentioned in Tarski (1931).) This is a very curious result, because [[Alonzo Church]] proved in 1936 that [[Peano arithmetic]] (the theory of [[natural number]]s) is ''not'' decidable. Peano arithmetic is also incomplete by [[Gödel's incompleteness theorem]]. In his 1953 ''Undecidable theories'', Tarski et al. showed that many mathematical systems, including [[lattice theory]], abstract [[projective geometry]], and [[closure algebra]]s, are all undecidable. The theory of [[Abelian group]]s is decidable, but that of non-Abelian groups is not.


In the 1920s and 30s, Tarski often taught high school [[geometry]]. Using some ideas of [[Mario Pieri]], in 1926 Tarski devised an original [[axiomatization]] for plane [[Euclidean geometry]], one considerably more concise than [[Hilbert's axioms|Hilbert's]].<ref>{{Cite web |url=https://ceur-ws.org/Vol-1785/F2.pdf |title=Tarski's Geometry and the Euclidean Plane in Mizar |website=ceur-ws.org |author=Adam Grabowski |access-date=28 April 2023}}</ref> [[Tarski's axioms]] form a first-order theory devoid of set theory, whose individuals are [[Point (geometry)|points]], and having only two primitive [[finitary relation|relations]]. In 1930, he proved this theory decidable because it can be mapped into another theory he had already proved decidable, namely his first-order theory of the real numbers.
While teaching at the Stefan Żeromski Gimnazjum in the 1920s and 30s, Tarski often taught [[geometry]].{{sfn|McFarland|McFarland|Smith|2014|loc=Section 9.2: Teaching geometry, pp. 179–184}} Using some ideas of [[Mario Pieri]], in 1926 Tarski devised an original [[axiomatization]] for plane [[Euclidean geometry]], one considerably more concise than [[Hilbert's axioms|Hilbert's]].<ref>{{Cite web |url=https://ceur-ws.org/Vol-1785/F2.pdf |title=Tarski's Geometry and the Euclidean Plane in Mizar |website=ceur-ws.org |author=Adam Grabowski |access-date=28 April 2023}}</ref> [[Tarski's axioms]] form a first-order theory devoid of set theory, whose individuals are [[Point (geometry)|points]], and having only two primitive [[finitary relation|relations]]. In 1930, he proved this theory decidable because it can be mapped into another theory he had already proved decidable, namely his first-order theory of the real numbers.


In 1929 he showed that much of Euclidean [[solid geometry]] could be recast as a second-order theory whose individuals are ''spheres'' (a [[primitive notion]]), a single primitive binary relation "is contained in", and two axioms that, among other things, imply that containment [[partial order|partially orders]] the spheres. Relaxing the requirement that all individuals be spheres yields a formalization of [[mereology]] far easier to exposit than [[Lesniewski]]'s variant. Near the end of his life, Tarski wrote a very long letter, published as Tarski and Givant (1999), summarizing his work on geometry.<ref>{{Cite journal |url=https://www.semanticscholar.org/paper/Tarski's-System-of-Geometry-Tarski-Givant/f9dc27b0f3f9436f0b194ecc6f558a74d346e0e6 |title=Tarski's System of Geometry |journal=The Bulletin of Symbolic Logic |doi=10.2307/421089 |jstor=421089 |s2cid=18551419 |access-date=28 April 2023 |last1=Tarski |first1=Alfred |last2=Givant |first2=Steven |year=1999 |volume=5 |issue=2 |pages=175–214 }}</ref>
In 1929 he showed that much of Euclidean [[solid geometry]] could be recast as a second-order theory whose individuals are ''spheres'' (a [[primitive notion]]), a single primitive binary relation "is contained in", and two axioms that, among other things, imply that containment [[partial order|partially orders]] the spheres. Relaxing the requirement that all individuals be spheres yields a formalization of [[mereology]] far easier to exposit than [[Lesniewski]]'s variant. Near the end of his life, Tarski wrote a very long letter, published as Tarski and Givant (1999), summarizing his work on geometry.<ref>{{Cite journal |title=Tarski's System of Geometry |journal=The Bulletin of Symbolic Logic |doi=10.2307/421089 |jstor=421089 |s2cid=18551419 |last1=Tarski |first1=Alfred |last2=Givant |first2=Steven |year=1999 |volume=5 |issue=2 |pages=175–214 }}</ref>


''Cardinal Algebras'' studied algebras whose models include the arithmetic of [[cardinal number]]s. ''Ordinal Algebras'' sets out an algebra for the additive theory of [[order type]]s. Cardinal, but not ordinal, addition commutes.
''Cardinal Algebras'' studied algebras whose models include the arithmetic of [[cardinal number]]s. ''Ordinal Algebras'' sets out an algebra for the additive theory of [[order type]]s. Cardinal, but not ordinal, addition commutes.


In 1941, Tarski published an important paper on [[binary relation]]s, which began the work on [[relation algebra]] and its [[metamathematics]] that occupied Tarski and his students for much of the balance of his life. While that exploration (and the closely related work of [[Roger Lyndon]]) uncovered some important limitations of relation algebra, Tarski also showed (Tarski and Givant 1987) that relation algebra can express most [[axiomatic set theory]] and [[Peano arithmetic]]. For an introduction to [[relation algebra]], see Maddux (2006). In the late 1940s, Tarski and his students devised [[cylindric algebra]]s, which are to [[first-order logic]] what the [[two-element Boolean algebra]] is to classical [[sentential logic]]. This work culminated in the two monographs by Tarski, Henkin, and Monk (1971, 1985).<ref>{{Cite web |url=https://goodmancoaching.nl/tarskis-convention-t-and-inductive-definition/ |title=Tarski's convention-T and inductive definition? |website=goodmancoaching.nl |date=22 May 2022 |access-date=28 April 2023}}</ref>
In 1941, Tarski published an important paper on [[binary relation]]s, which began the work on [[relation algebra]] and its [[metamathematics]] that occupied Tarski and his students for much of the balance of his life. While that exploration (and the closely related work of [[Roger Lyndon]]) uncovered some important limitations of relation algebra, Tarski also showed (Tarski and Givant 1987) that relation algebra can express most [[axiomatic set theory]] and [[Peano arithmetic]]. For an introduction to [[relation algebra]], see Maddux (2006). In the late 1940s, Tarski and his students devised [[cylindric algebra]]s, which are to [[first-order logic]] what the [[two-element Boolean algebra]] is to classical [[sentential logic]]. This work culminated in the two monographs by Tarski, Henkin, and Monk (1971, 1985).<ref>{{Cite news |url=https://goodmancoaching.nl/tarskis-convention-t-and-inductive-definition/ |title=Tarski's convention-T and inductive definition? |newspaper=Goodmancoaching |date=22 May 2022 |access-date=28 April 2023}}</ref>


==Work in logic==
==Work in logic==
Tarski's student, Vaught, has ranked Tarski as one of the four greatest logicians of all time &mdash; along with [[Aristotle]], [[Gottlob Frege]], and [[Kurt Gödel]].<ref name=FFintro/><ref name="Vaught">{{cite journal|last=Vaught|first=Robert L.|date=Dec 1986|title=Alfred Tarski's Work in Model Theory|journal=[[Journal of Symbolic Logic]]|volume=51|issue=4|pages=869–882|doi=10.2307/2273900|jstor=2273900|s2cid=27153078 }}</ref><ref name="Restall">{{cite web|url=http://consequently.org/writing/logicians/|title=Great Moments in Logic |last=Restall|first=Greg|date=2002–2006|access-date=2009-01-03| archive-url= https://web.archive.org/web/20081206052240/http://consequently.org/writing/logicians/| archive-date= 6 December 2008 | url-status= live}}</ref> <!-- Of these four, he was by far the most prolific author. MORE THAN ARISTOTLE??? PROVIDE Reference! --> However, Tarski often expressed great admiration for [[Logic of relatives|Charles Sanders Peirce]], particularly for his pioneering work in the [[Finitary relation|logic of relations]].
Tarski's student, [[Robert Lawson Vaught]], has ranked Tarski as one of the four greatest logicians of all time &mdash; along with [[Aristotle]], [[Gottlob Frege]], and [[Kurt Gödel]].<ref name=FFintro/><ref name="Vaught">{{cite journal|last=Vaught|first=Robert L.|date=Dec 1986|title=Alfred Tarski's Work in Model Theory|journal=[[Journal of Symbolic Logic]]|volume=51|issue=4|pages=869–882|doi=10.2307/2273900|jstor=2273900|s2cid=27153078 }}</ref><ref name="Restall">{{cite web|url=http://consequently.org/writing/logicians/|title=Great Moments in Logic |last=Restall|first=Greg|date=2002–2006|access-date=2009-01-03| archive-url= https://web.archive.org/web/20081206052240/http://consequently.org/writing/logicians/| archive-date= 6 December 2008 | url-status= live}}</ref> <!-- Of these four, he was by far the most prolific author. MORE THAN ARISTOTLE??? PROVIDE Reference! --> However, Tarski often expressed great admiration for [[Logic of relatives|Charles Sanders Peirce]], particularly for his pioneering work in the [[Finitary relation|logic of relations]].


Tarski produced axioms for ''logical consequence'' and worked on [[deductive system]]s, the algebra of logic, and the theory of definability. His semantic methods, which culminated in the model theory he and a number of his Berkeley students developed in the 1950s and 60s, radically transformed Hilbert's proof-theoretic metamathematics.
Tarski produced axioms for ''logical consequence'' and worked on [[deductive system]]s, the algebra of logic, and the theory of definability. His semantic methods, which culminated in the model theory he and a number of his Berkeley students developed in the 1950s and 60s, radically transformed Hilbert's proof-theoretic metamathematics.
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{{blockquote|In [Tarski's] view, metamathematics became similar to any mathematical discipline. Not only can its concepts and results be mathematized, but they actually can be integrated into mathematics. ... Tarski destroyed the borderline between metamathematics and mathematics. He objected to restricting the role of metamathematics to the foundations of mathematics.<ref name="Sinaceur">{{cite journal|last=Sinaceur|first=Hourya|title=Alfred Tarski: Semantic Shift, Heuristic Shift in Metamathematics|journal=Synthese|volume=126|issue=1–2|pages=49–65|issn=0039-7857|doi=10.1023/A:1005268531418|year=2001|s2cid=28783841|url=https://halshs.archives-ouvertes.fr/halshs-01119489}}</ref>}}
{{blockquote|In [Tarski's] view, metamathematics became similar to any mathematical discipline. Not only can its concepts and results be mathematized, but they actually can be integrated into mathematics. ... Tarski destroyed the borderline between metamathematics and mathematics. He objected to restricting the role of metamathematics to the foundations of mathematics.<ref name="Sinaceur">{{cite journal|last=Sinaceur|first=Hourya|title=Alfred Tarski: Semantic Shift, Heuristic Shift in Metamathematics|journal=Synthese|volume=126|issue=1–2|pages=49–65|issn=0039-7857|doi=10.1023/A:1005268531418|year=2001|s2cid=28783841|url=https://halshs.archives-ouvertes.fr/halshs-01119489}}</ref>}}


Tarski's 1936 article "On the concept of logical consequence" argued that the conclusion of an argument will follow logically from its premises if and only if every model of the premises is a model of the conclusion.<ref>{{Cite journal |url=https://www.semanticscholar.org/paper/Tarski-on-Logical-Consequence-G%C3%B3mez-Torrente/2aa96af14437c1f2ae8080c68853ffac1d5f9b4a |title=Tarski on Logical Consequence |journal=Notre Dame Journal of Formal Logic |year=1996 |doi=10.1305/ndjfl/1040067321 |s2cid=13217777 |access-date=28 April 2023 |last1=Gómez-Torrente |first1=Mario |volume=37 }}</ref> In 1937, he published a paper presenting clearly his views on the nature and purpose of the deductive method, and the role of logic in scientific studies.<ref name="mathshistory.st-andrews.ac.uk"/> His high school and undergraduate teaching on logic and axiomatics culminated in a classic short text, published first in Polish, then in German translation, and finally in a 1941 English translation as ''Introduction to Logic and to the Methodology of Deductive Sciences''.<ref>{{Cite web |url=https://archive.org/details/in.ernet.dli.2015.471634 |title=Introduction To Logic And To The Methodology Of Deductive Sciences |website=archive.org |access-date=28 April 2023}}</ref>
Tarski's 1936 article "On the concept of logical consequence" argued that the conclusion of an argument will follow logically from its premises if and only if every model of the premises is a model of the conclusion.<ref>{{Cite journal |title=Tarski on Logical Consequence |journal=Notre Dame Journal of Formal Logic |year=1996 |doi=10.1305/ndjfl/1040067321 |s2cid=13217777 |last1=Gómez-Torrente |first1=Mario |volume=37 |doi-access=free }}</ref> In 1937, he published a paper presenting clearly his views on the nature and purpose of the deductive method, and the role of logic in scientific studies.<ref name="mathshistory.st-andrews.ac.uk"/> His high school and undergraduate teaching on logic and axiomatics culminated in a classic short text, published first in Polish, then in German translation, and finally in a 1941 English translation as ''Introduction to Logic and to the Methodology of Deductive Sciences''.<ref>{{Cite web |url=https://archive.org/details/in.ernet.dli.2015.471634 |title=Introduction To Logic And To The Methodology Of Deductive Sciences |website=archive.org |access-date=28 April 2023}}</ref>


Tarski's 1969 "Truth and proof" considered both [[Gödel's incompleteness theorems]] and [[Tarski's undefinability theorem]], and mulled over their consequences for the axiomatic method in mathematics.
Tarski's 1969 "Truth and proof" considered both [[Gödel's incompleteness theorems]] and [[Tarski's undefinability theorem]], and mulled over their consequences for the axiomatic method in mathematics.
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===Truth in formalized languages===
===Truth in formalized languages===
{{main|Semantic theory of truth}}
{{main|Semantic theory of truth}}
In 1933, Tarski published a very long paper in Polish, titled "Pojęcie prawdy w językach nauk dedukcyjnych",<ref>Alfred Tarski, "POJĘCIE PRAWDY W JĘZYKACH NAUK DEDUKCYJNYCH", Towarszystwo Naukowe Warszawskie, Warszawa, 1933. [http://www.archiwum.wfis.uw.edu.pl/bibfis/index.php?option=com_content&view=article&id=129:a-tarski-pojcie-prawdy-w-jzykach-nauk-dedukcyjnych&catid=56:marginalia&Itemid=106 (Text in Polish in the Digital Library WFISUW-IFISPAN-PTF)].</ref> "Setting out a mathematical definition of truth for formal languages." The 1935 German translation was titled "Der Wahrheitsbegriff in den formalisierten Sprachen", "The concept of truth in formalized languages", sometimes shortened to "Wahrheitsbegriff". An English translation appeared in the 1956 first edition of the volume ''Logic, Semantics, Metamathematics''. This collection of papers from 1923 to 1938 is an event in 20th-century [[analytic philosophy]], a contribution to [[Mathematical logic|symbolic logic]], [[semantics]], and the [[philosophy of language]]. For a brief discussion of its content, see [[Convention T]] (and also [[T-schema]]).
In 1933, Tarski published a very long paper in Polish, titled "Pojęcie prawdy w językach nauk dedukcyjnych",<ref>Alfred Tarski, "POJĘCIE PRAWDY W JĘZYKACH NAUK DEDUKCYJNYCH", Towarszystwo Naukowe Warszawskie, Warszawa, 1933. [http://www.archiwum.wfis.uw.edu.pl/bibfis/index.php?option=com_content&view=article&id=129:a-tarski-pojcie-prawdy-w-jzykach-nauk-dedukcyjnych&catid=56:marginalia&Itemid=106 (Text in Polish in the Digital Library WFISUW-IFISPAN-PTF)] {{Webarchive|url=https://web.archive.org/web/20160304000353/http://www.archiwum.wfis.uw.edu.pl/bibfis/index.php?option=com_content&view=article&id=129:a-tarski-pojcie-prawdy-w-jzykach-nauk-dedukcyjnych&catid=56:marginalia&Itemid=106 |date=2016-03-04 }}.</ref> "Setting out a mathematical definition of truth for formal languages." The 1935 German translation was titled "Der Wahrheitsbegriff in den formalisierten Sprachen", "The concept of truth in formalized languages", sometimes shortened to "Wahrheitsbegriff". An English translation appeared in the 1956 first edition of the volume ''[[Logic, Semantics, Metamathematics]]''. This collection of papers from 1923 to 1938 is an event in 20th-century [[analytic philosophy]], a contribution to [[Mathematical logic|symbolic logic]], [[semantics]], and the [[philosophy of language]]. For a brief discussion of its content, see [[Convention T]] (and also [[T-schema]]).


Some recent philosophical debate examines the extent to which Tarski's theory of truth for formalized languages can be seen as a [[correspondence theory of truth]]. The debate centers on how to read Tarski's condition of material adequacy for a true definition. That condition requires that the truth theory have the following as theorems for all sentences p of the language for which truth is being defined:
A philosophical debate examines the extent to which Tarski's theory of truth for formalized languages can be seen as a [[correspondence theory of truth]]. The debate centers on how to read Tarski's condition of material adequacy for a true definition. That condition requires that the truth theory have the following as theorems for all sentences p of the language for which truth is being defined:


: "p" is true [[if and only if]] p.
: "p" is true [[if and only if]] p.
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{{blockquote|"Snow is white" is true if and only if snow is white}}
{{blockquote|"Snow is white" is true if and only if snow is white}}


as expressing merely a [[deflationary theory of truth]] or as embodying [[truth]] as a more substantial property (see Kirkham 1992). It is important to realize that Tarski's theory of truth is for formalized languages, so examples in natural language are not illustrations of the use of Tarski's theory of truth.
as expressing merely a [[deflationary theory of truth]] or as embodying [[truth]] as a more substantial property (see Kirkham 1992).


===Logical consequence===
===Logical consequence===
In 1936, Tarski published Polish and German versions of a lecture, “On the Concept of Following Logically",<ref name="Tarski2002">{{cite journal
In 1936, Tarski published Polish and German versions of a lecture he had given the preceding year at the International Congress of Scientific Philosophy in Paris. <!-- (First appearance in English?) --> A new English translation of this paper, Tarski (2002), highlights the many differences between the German and Polish versions of the paper and corrects a number of mistranslations in Tarski (1983).
|last1=Tarski
|first1=Alfred
|title=On the Concept of Following Logically
|date=2002
|volume=23
|pages=155–196
|doi=10.1080/0144534021000036683
|journal = History and Philosophy of Logic|issue=3
|s2cid=120956516
}}</ref>
he had given the preceding year at the International Congress of Scientific Philosophy in Paris. <!-- (First appearance in English?) --> A new English translation of this paper, Tarski (2002), highlights the many differences between the German and Polish versions of the paper and corrects a number of mistranslations in Tarski (1983).<ref name="Tarski2002" />


This publication set out the modern [[model theory|model-theoretic]] definition of (semantic) logical consequence, or at least the basis for it. Whether Tarski's notion was entirely the modern one turns on whether he intended to admit models with varying domains (and in particular, models with domains of different [[cardinal number|cardinalities]]). This question is a matter of some debate in the current philosophical literature. [[John Etchemendy]] stimulated much of the recent discussion about Tarski's treatment of varying domains.<ref>{{cite book|last=Etchemendy|first=John|title=The Concept of Logical Consequence|publisher=Stanford CA: CSLI Publications|year=1999|isbn=978-1-57586-194-4}}</ref>
This publication set out the modern [[model theory|model-theoretic]] definition of (semantic) logical consequence, or at least the basis for it. Whether Tarski's notion was entirely the modern one turns on whether he intended to admit models with varying domains (and in particular, models with domains of different [[cardinal number|cardinalities]]).{{citation needed|date=July 2023}} This question is a matter of some debate in the philosophical literature. [[John Etchemendy]] stimulated much of the discussion about Tarski's treatment of varying domains.<ref>{{cite book|last=Etchemendy|first=John|title=The Concept of Logical Consequence|publisher=Stanford CA: CSLI Publications|year=1999|isbn=978-1-57586-194-4}}</ref>


Tarski ends by pointing out that his definition of logical consequence depends upon a division of terms into the logical and the extra-logical and he expresses some skepticism that any such objective division will be forthcoming. "What are Logical Notions?" can thus be viewed as continuing "On the Concept of Logical Consequence".
Tarski ends by pointing out that his definition of logical consequence depends upon a division of terms into the logical and the extra-logical and he expresses some skepticism that any such objective division will be forthcoming. "What are Logical Notions?" can thus be viewed as continuing "On the Concept of Logical Consequence".{{citation needed|date=July 2023}}


===Logical notions===
===Logical notions===
[[File:Alfred Tarski.jpeg|thumb|Alfred Tarski at Berkeley]]
[[File:Alfred Tarski.jpeg|thumb|Alfred Tarski at Berkeley]]
Another theory of Tarski's attracting attention in the recent philosophical literature is that outlined in his "What are Logical Notions?" (Tarski 1986). This is the published version of a talk that he gave originally in 1966 in London and later in 1973 in [[Buffalo, New York|Buffalo]]; it was edited without his direct involvement by [[John Corcoran (logician)|John Corcoran]]. It became the most cited paper in the journal ''History and Philosophy of Logic''.<ref>{{Cite web | url=http://www.tandfonline.com/action/showMostCitedArticles?journalCode=thpl20 | title=History and Philosophy of Logic}}</ref>
Tarski's "What are Logical Notions?" (Tarski 1986) is the published version of a talk that he gave originally in 1966 in London and later in 1973 in [[Buffalo, New York|Buffalo]]; it was edited without his direct involvement by [[John Corcoran (logician)|John Corcoran]]. It became the most cited paper in the journal ''History and Philosophy of Logic''.<ref>{{Cite web | url=http://www.tandfonline.com/action/showMostCitedArticles?journalCode=thpl20 | title=History and Philosophy of Logic}}</ref>


In the talk, Tarski proposed demarcation of logical operations (which he calls "notions") from non-logical. The suggested criteria were derived from the [[Erlangen program]] of the 19th-century German mathematician [[Felix Klein]]. Mautner (in 1946), and possibly an article by the Portuguese mathematician Sebastiao e Silva, anticipated Tarski in applying the Erlangen Program to logic.
In the talk, Tarski proposed demarcation of logical operations (which he calls "notions") from non-logical. The suggested criteria were derived from the [[Erlangen program]] of the 19th-century German mathematician [[Felix Klein]]. Mautner (in 1946), and possibly{{clarify|date=July 2023}} an article by the Portuguese mathematician [[José Sebastião e Silva]], anticipated Tarski in applying the Erlangen Program to logic.{{citation needed|date=July 2023}}


That program classified the various types of geometry ([[Euclidean geometry]], [[affine geometry]], [[topology]], etc.) by the type of one-one transformation of space onto itself that left the objects of that geometrical theory invariant. (A one-to-one transformation is a functional map of the space onto itself so that every point of the space is associated with or mapped to one other point of the space. So, "rotate 30 degrees" and "magnify by a factor of 2" are intuitive descriptions of simple uniform one-one transformations.) Continuous transformations give rise to the objects of topology, similarity transformations to those of Euclidean geometry, and so on.
The Erlangen program classified the various types of geometry ([[Euclidean geometry]], [[affine geometry]], [[topology]], etc.) by the type of one-one transformation of space onto itself that left the objects of that geometrical theory invariant. (A one-to-one transformation is a functional map of the space onto itself so that every point of the space is associated with or mapped to one other point of the space. So, "rotate 30 degrees" and "magnify by a factor of 2" are intuitive descriptions of simple uniform one-one transformations.) Continuous transformations give rise to the objects of topology, similarity transformations to those of Euclidean geometry, and so on.{{citation needed|date=July 2023}}


As the range of permissible transformations becomes broader, the range of objects one is able to distinguish as preserved by the application of the transformations becomes narrower. Similarity transformations are fairly narrow (they preserve the relative distance between points) and thus allow us to distinguish relatively many things (e.g., equilateral triangles from non-equilateral triangles). Continuous transformations (which can intuitively be thought of as transformations which allow non-uniform stretching, compression, bending, and twisting, but no ripping or glueing) allow us to distinguish a [[polygon]] from an [[annulus (mathematics)|annulus]] (ring with a hole in the centre), but do not allow us to distinguish two polygons from each other.
As the range of permissible transformations becomes broader, the range of objects one is able to distinguish as preserved by the application of the transformations becomes narrower. Similarity transformations are fairly narrow (they preserve the relative distance between points) and thus allow us to distinguish relatively many things (e.g., equilateral triangles from non-equilateral triangles). Continuous transformations (which can intuitively be thought of as transformations which allow non-uniform stretching, compression, bending, and twisting, but no ripping or glueing) allow us to distinguish a [[polygon]] from an [[annulus (mathematics)|annulus]] (ring with a hole in the centre), but do not allow us to distinguish two polygons from each other.{{citation needed|date=July 2023}}


Tarski's proposal was to demarcate the logical notions by considering all possible one-to-one transformations ([[automorphism]]s) of a domain onto itself. By domain is meant the [[universe of discourse]] of a model for the semantic theory of logic. If one identifies the [[truth value]] True with the domain set and the truth-value False with the empty set, then the following operations are counted as logical under the proposal:
Tarski's proposal{{which|date=July 2023}} was to demarcate the logical notions by considering all possible one-to-one transformations ([[automorphism]]s) of a domain onto itself. By domain is meant the [[universe of discourse]] of a model for the semantic theory of logic. If one identifies the [[truth value]] True with the domain set and the truth-value False with the empty set, then the following operations are counted as logical under the proposal:


# ''[[Truth-function]]s'': All truth-functions are admitted by the proposal. This includes, but is not limited to, all ''n''-ary truth-functions for finite ''n''. (It also admits of truth-functions with any infinite number of places.)
# ''[[Truth-function]]s'': All truth-functions are admitted by the proposal. This includes, but is not limited to, all ''n''-ary truth-functions for finite ''n''. (It also admits of truth-functions with any infinite number of places.)
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# ''Set-Theoretic relations'': Relations such as [[inclusion (set theory)|inclusion]], [[Intersection (set theory)|intersection]] and [[Union (set theory)|union]] applied to [[subset]]s of the domain are logical in the present sense.
# ''Set-Theoretic relations'': Relations such as [[inclusion (set theory)|inclusion]], [[Intersection (set theory)|intersection]] and [[Union (set theory)|union]] applied to [[subset]]s of the domain are logical in the present sense.
# ''Set membership'': Tarski ended his lecture with a discussion of whether the set membership relation counted as logical in his sense. (Given the reduction of (most of) mathematics to set theory, this was, in effect, the question of whether most or all of mathematics is a part of logic.) He pointed out that set membership is logical if set theory is developed along the lines of [[type theory]], but is extralogical if set theory is set out axiomatically, as in the canonical [[Zermelo–Fraenkel set theory]].
# ''Set membership'': Tarski ended his lecture with a discussion of whether the set membership relation counted as logical in his sense. (Given the reduction of (most of) mathematics to set theory, this was, in effect, the question of whether most or all of mathematics is a part of logic.) He pointed out that set membership is logical if set theory is developed along the lines of [[type theory]], but is extralogical if set theory is set out axiomatically, as in the canonical [[Zermelo–Fraenkel set theory]].
# ''Logical notions of higher order'': While Tarski confined his discussion to operations of first-order logic, there is nothing about his proposal that necessarily restricts it to first-order logic. (Tarski likely restricted his attention to first-order notions as the talk was given to a non-technical audience.) So, higher-order quantifiers and predicates are admitted as well.
# ''Logical notions of higher order'': While Tarski confined his discussion to operations of first-order logic, there is nothing about his proposal that necessarily restricts it to first-order logic. (Tarski likely restricted his attention to first-order notions as the talk was given to a non-technical audience.) So, higher-order quantifiers and predicates are admitted as well.{{citation needed|date=July 2023}}


In some ways the present proposal is the obverse of that of Lindenbaum and Tarski (1936), who proved that all the logical operations of [[Bertrand Russell]]'s and [[Alfred North Whitehead|Whitehead]]'s ''[[Principia Mathematica]]'' are invariant under one-to-one transformations of the domain onto itself. The present proposal is also employed in Tarski and Givant (1987).<ref>{{Cite journal |url=https://www.cambridge.org/core/journals/journal-of-symbolic-logic/article/abs/alfred-tarski-and-steven-givant-a-formalization-of-set-theory-without-variables-american-mathematical-society-colloquium-publications-vol-41-american-mathematical-society-providence1987-xxi-318-pp/9B436E22D3B3785570ABE9C85F870308 |title=Alfred Tarski and Steven Givant. A formalization of set theory without variables. American Mathematical Society colloquium publications, vol. 41. American Mathematical Society, Providence1987, xxi + 318 pp. |journal=The Journal of Symbolic Logic |date=12 March 2014 |volume=55 |issue=1 |pages=350–352 |doi=10.2307/2274990 |jstor=2274990 |access-date=28 April 2023 |last1=Németi |first1=István }}</ref>
In some ways the present proposal is the obverse of that of Lindenbaum and Tarski (1936), who proved that all the logical operations of [[Bertrand Russell]]'s and [[Alfred North Whitehead|Whitehead]]'s ''[[Principia Mathematica]]'' are invariant under one-to-one transformations of the domain onto itself. The present proposal is also employed in Tarski and [[Steven Givant|Givant]] (1987).<ref>{{Cite journal |url=https://www.cambridge.org/core/journals/journal-of-symbolic-logic/article/abs/alfred-tarski-and-steven-givant-a-formalization-of-set-theory-without-variables-american-mathematical-society-colloquium-publications-vol-41-american-mathematical-society-providence1987-xxi-318-pp/9B436E22D3B3785570ABE9C85F870308 |title=Alfred Tarski and Steven Givant. A formalization of set theory without variables. American Mathematical Society colloquium publications, vol. 41. American Mathematical Society, Providence1987, xxi + 318 pp. |journal=The Journal of Symbolic Logic |date=12 March 2014 |volume=55 |issue=1 |pages=350–352 |doi=10.2307/2274990 |jstor=2274990 |access-date=28 April 2023 |last1=Németi |first1=István }}</ref>


Solomon Feferman and Vann McGee further discussed Tarski's proposal in work published after his death. Feferman (1999) raises problems for the proposal and suggests a cure: replacing Tarski's preservation by automorphisms with preservation by arbitrary [[homomorphism]]s. In essence, this suggestion circumvents the difficulty Tarski's proposal has in dealing with a sameness of logical operation across distinct domains of a given cardinality and across domains of distinct cardinalities. Feferman's proposal results in a radical restriction of logical terms as compared to Tarski's original proposal. In particular, it ends up counting as logical only those operators of standard first-order logic without identity.
[[Solomon Feferman]] and [[Vann McGee]] further discussed Tarski's proposal{{which|date=July 2023}} in work published after his death. Feferman (1999) raises problems for the proposal and suggests a cure: replacing Tarski's preservation by automorphisms with preservation by arbitrary [[homomorphism]]s. In essence, this suggestion circumvents the difficulty Tarski's proposal has in dealing with a sameness of logical operation across distinct domains of a given cardinality and across domains of distinct cardinalities. Feferman's proposal results in a radical restriction of logical terms as compared to Tarski's original proposal. In particular, it ends up counting as logical only those operators of standard first-order logic without identity.{{citation needed|date=July 2023}}


McGee (1996) provides a precise account of what operations are logical in the sense of Tarski's proposal in terms of expressibility in a language that extends first-order logic by allowing arbitrarily long conjunctions and disjunctions, and quantification over arbitrarily many variables. "Arbitrarily" includes a countable infinity.<ref>{{Cite journal |url=https://www.jstor.org/stable/1523019 |title=Revision |journal=Philosophical Issues |jstor=1523019 |access-date=28 April 2023 |last1=McGee |first1=Vann |year=1997 |volume=8 |pages=387–406 |doi=10.2307/1523019 }}</ref>
[[Vann McGee]] (1996) provides a precise account of what operations are logical in the sense of Tarski's proposal in terms of expressibility in a language that extends first-order logic by allowing arbitrarily long conjunctions and disjunctions, and quantification over arbitrarily many variables. "Arbitrarily" includes a countable infinity.<ref>{{Cite journal |url=https://www.jstor.org/stable/1523019 |title=Revision |journal=Philosophical Issues |jstor=1523019 |access-date=28 April 2023 |last1=McGee |first1=Vann |year=1997 |volume=8 |pages=387–406 |doi=10.2307/1523019 }}</ref>


==Selected publications==
==Selected publications==
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* 1986. ''The Collected Papers of Alfred Tarski'', 4 vols. Givant, S. R., and McKenzie, R. N., eds. Birkhäuser.
* 1986. ''The Collected Papers of Alfred Tarski'', 4 vols. Givant, S. R., and McKenzie, R. N., eds. Birkhäuser.
* {{cite journal | author = Givant Steven | year = 1986 | title = Bibliography of Alfred Tarski | journal = Journal of Symbolic Logic | volume = 51 | issue = 4| pages = 913–41 | doi=10.2307/2273905| jstor = 2273905 | s2cid = 44369365 }}
* {{cite journal | author = Givant Steven | year = 1986 | title = Bibliography of Alfred Tarski | journal = Journal of Symbolic Logic | volume = 51 | issue = 4| pages = 913–41 | doi=10.2307/2273905| jstor = 2273905 | s2cid = 44369365 }}
* 1983 (1956). ''Logic, Semantics, Metamathematics: Papers from 1923 to 1938 by Alfred Tarski'', Corcoran, J., ed. Hackett. 1st edition edited and translated by J. H. Woodger, Oxford Uni. Press.<ref>{{cite journal|author=Halmos, Paul|author-link=Paul Halmos|title=Review: ''Logic, semantics, metamathematics. Papers from 1923 to 1938'' by Alfred Tarski; translated by J. H. Woodger|journal=Bull. Amer. Math. Soc.|year=1957|volume=63|issue=2|pages=155–156|url=https://www.ams.org/journals/bull/1957-63-02/S0002-9904-1957-10115-3/S0002-9904-1957-10115-3.pdf|doi=10.1090/S0002-9904-1957-10115-3|doi-access=free}}</ref> This collection contains translations from Polish of some of Tarski's most important papers of his early career, including ''The Concept of Truth in Formalized Languages'' and ''On the Concept of Logical Consequence'' discussed above.
* 1983 (1956). ''Logic, Semantics, Metamathematics: Papers from 1923 to 1938 by Alfred Tarski'', Corcoran, J., ed. Hackett. 1st edition edited and translated by [[J. H. Woodger]], Oxford Uni. Press.<ref>{{cite journal|author=Halmos, Paul|author-link=Paul Halmos|title=Review: ''Logic, semantics, metamathematics. Papers from 1923 to 1938'' by Alfred Tarski; translated by J. H. Woodger|journal=Bull. Amer. Math. Soc.|year=1957|volume=63|issue=2|pages=155–156|url=https://www.ams.org/journals/bull/1957-63-02/S0002-9904-1957-10115-3/S0002-9904-1957-10115-3.pdf|doi=10.1090/S0002-9904-1957-10115-3|doi-access=free}}</ref> This collection contains translations from Polish of some of Tarski's most important papers of his early career, including ''The Concept of Truth in Formalized Languages'' and ''On the Concept of Logical Consequence'' discussed above.


;Original publications of Tarski:
;Original publications of Tarski:
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* 1936. [http://gallica.bnf.fr/ark:/12148/bpt6k383668/f5.image.r=.langFR "Grundlegung der wissenschaftlichen Semantik"], ''Actes du Congrès international de philosophie scientifique, Sorbonne, Paris 1935'', vol. III, ''Language et pseudo-problèmes'', Paris, Hermann, 1936, pp.&nbsp;1–8 in Tarski (1983): 401–408.
* 1936. [http://gallica.bnf.fr/ark:/12148/bpt6k383668/f5.image.r=.langFR "Grundlegung der wissenschaftlichen Semantik"], ''Actes du Congrès international de philosophie scientifique, Sorbonne, Paris 1935'', vol. III, ''Language et pseudo-problèmes'', Paris, Hermann, 1936, pp.&nbsp;1–8 in Tarski (1983): 401–408.
* 1936. [http://gallica.bnf.fr/ark:/12148/bpt6k38370h/f5.image.r=.langFR "Über den Begriff der logischen Folgerung"], ''Actes du Congrès international de philosophie scientifique, Sorbonne, Paris 1935'', vol. VII, ''Logique'', Paris: Hermann, pp.&nbsp;1–11 in Tarski (1983): 409–420.
* 1936. [http://gallica.bnf.fr/ark:/12148/bpt6k38370h/f5.image.r=.langFR "Über den Begriff der logischen Folgerung"], ''Actes du Congrès international de philosophie scientifique, Sorbonne, Paris 1935'', vol. VII, ''Logique'', Paris: Hermann, pp.&nbsp;1–11 in Tarski (1983): 409–420.
* 1936 (with Adolf Lindenbaum). "On the Limitations of Deductive Theories" in Tarski (1983): 384–92.
* 1936 (with [[Adolf Lindenbaum]]). "On the Limitations of Deductive Theories" in Tarski (1983): 384–92.
* 1937. ''Einführung in die Mathematische Logik und in die Methodologie der Mathematik''. Springer, Wien (Vienna).
* 1937. ''Einführung in die Mathematische Logik und in die Methodologie der Mathematik''. Springer, Wien (Vienna).
* 1994 (1941).<ref>{{cite journal|author=Quine, W. V.|author-link=Willard Van Orman Quine|title=Review: ''Einführung in die mathematische Logik und in die Methodologie der Mathematik'' by Alfred Tarski. Vienna, Springer, 1937. x+166 pp.|journal=Bull. Amer. Math. Soc.|year=1938|volume=44|issue=5|pages=317–318|url=https://www.ams.org/journals/bull/1938-44-05/S0002-9904-1938-06731-6/S0002-9904-1938-06731-6.pdf|doi=10.1090/s0002-9904-1938-06731-6|doi-access=free}}</ref><ref>{{cite journal|author=Curry, Haskell B.|author-link=Haskell Curry|title=Review: ''Introduction to Logic and to the Methodology of Deductive Sciences'' by Alfred Tarski|journal=Bull. Amer. Math. Soc.|year=1942|volume=48|issue=7|pages=507–510|url=https://www.ams.org/journals/bull/1942-48-07/S0002-9904-1942-07698-1/S0002-9904-1942-07698-1.pdf|doi=10.1090/s0002-9904-1942-07698-1|doi-access=free}}</ref> ''Introduction to Logic and to the Methodology of Deductive Sciences''. Dover.
* 1994 (1941).<ref>{{cite journal|author=Quine, W. V.|author-link=Willard Van Orman Quine|title=Review: ''Einführung in die mathematische Logik und in die Methodologie der Mathematik'' by Alfred Tarski. Vienna, Springer, 1937. x+166 pp.|journal=Bull. Amer. Math. Soc.|year=1938|volume=44|issue=5|pages=317–318|url=https://www.ams.org/journals/bull/1938-44-05/S0002-9904-1938-06731-6/S0002-9904-1938-06731-6.pdf|doi=10.1090/s0002-9904-1938-06731-6|doi-access=free}}</ref><ref>{{cite journal|author=Curry, Haskell B.|author-link=Haskell Curry|title=Review: ''Introduction to Logic and to the Methodology of Deductive Sciences'' by Alfred Tarski|journal=Bull. Amer. Math. Soc.|year=1942|volume=48|issue=7|pages=507–510|url=https://www.ams.org/journals/bull/1942-48-07/S0002-9904-1942-07698-1/S0002-9904-1942-07698-1.pdf|doi=10.1090/s0002-9904-1942-07698-1|doi-access=free}}</ref> ''Introduction to Logic and to the Methodology of Deductive Sciences''. Dover.
Line 193: Line 202:
* 1948. ''A decision method for elementary algebra and geometry''. Santa Monica CA: RAND Corp.<ref>{{cite journal|author=McNaughton, Robert|title=Review: ''A decision method for elementary algebra and geometry'' by A. Tarski|journal=Bull. Amer. Math. Soc.|year=1953|volume=59|issue=1|pages=91–93|url=https://www.ams.org/journals/bull/1953-59-01/S0002-9904-1953-09664-1/S0002-9904-1953-09664-1.pdf|doi=10.1090/s0002-9904-1953-09664-1|doi-access=free}}</ref>
* 1948. ''A decision method for elementary algebra and geometry''. Santa Monica CA: RAND Corp.<ref>{{cite journal|author=McNaughton, Robert|title=Review: ''A decision method for elementary algebra and geometry'' by A. Tarski|journal=Bull. Amer. Math. Soc.|year=1953|volume=59|issue=1|pages=91–93|url=https://www.ams.org/journals/bull/1953-59-01/S0002-9904-1953-09664-1/S0002-9904-1953-09664-1.pdf|doi=10.1090/s0002-9904-1953-09664-1|doi-access=free}}</ref>
* 1949. ''Cardinal Algebras''. Oxford Univ. Press.<ref>{{cite journal|author=Birkhoff, Garrett|author-link=Garrett Birkhoff|title=Review: ''Cardinal algebras'' by A. Tarski|journal=Bull. Amer. Math. Soc.|year=1950|volume=56|issue=2|pages=208–209|url=https://www.ams.org/journals/bull/1950-56-02/S0002-9904-1950-09394-X/S0002-9904-1950-09394-X.pdf|doi=10.1090/s0002-9904-1950-09394-x|doi-access=free}}</ref>
* 1949. ''Cardinal Algebras''. Oxford Univ. Press.<ref>{{cite journal|author=Birkhoff, Garrett|author-link=Garrett Birkhoff|title=Review: ''Cardinal algebras'' by A. Tarski|journal=Bull. Amer. Math. Soc.|year=1950|volume=56|issue=2|pages=208–209|url=https://www.ams.org/journals/bull/1950-56-02/S0002-9904-1950-09394-X/S0002-9904-1950-09394-X.pdf|doi=10.1090/s0002-9904-1950-09394-x|doi-access=free}}</ref>
* 1953 (with Mostowski and Raphael Robinson). ''Undecidable theories''. North Holland.<ref>{{cite journal|author=Gál, Ilse Novak|title=Review: ''Undecidable theories'' by Alfred Tarski in collaboration with A. Mostowsku and R. M. Robinson|journal=Bull. Amer. Math. Soc.|year=1954|volume=60|issue=6|pages=570–572|url=https://www.ams.org/journals/bull/1954-60-06/S0002-9904-1954-09858-0/S0002-9904-1954-09858-0.pdf|doi=10.1090/S0002-9904-1954-09858-0|doi-access=free}}</ref>
* 1953 (with [[A. Mostowski|Mostowski]] and [[R. M. Robinson|Raphael Robinson]]). ''Undecidable theories''. North Holland.<ref>{{cite journal|author=Gál, Ilse Novak|title=Review: ''Undecidable theories'' by Alfred Tarski in collaboration with A. Mostowsku and R. M. Robinson|journal=Bull. Amer. Math. Soc.|year=1954|volume=60|issue=6|pages=570–572|url=https://www.ams.org/journals/bull/1954-60-06/S0002-9904-1954-09858-0/S0002-9904-1954-09858-0.pdf|doi=10.1090/S0002-9904-1954-09858-0|doi-access=free}}</ref>
* 1956. ''Ordinal algebras''. North-Holland.
* 1956. ''Ordinal algebras''. North-Holland.
* 1965. "A simplified formalization of predicate logic with identity", ''Archiv für Mathematische Logik und Grundlagenforschung 7'': 61-79
* 1965. "A simplified formalization of predicate logic with identity", ''Archiv für Mathematische Logik und Grundlagenforschung 7'': 61-79
* 1969. "[https://web.archive.org/web/20141229081319/http://people.scs.carleton.ca/~bertossi/logic/material/tarski.pdf Truth and Proof]", ''Scientific American 220'': 63–77.
* 1969. "[https://web.archive.org/web/20141229081319/http://people.scs.carleton.ca/~bertossi/logic/material/tarski.pdf Truth and Proof]", ''Scientific American 220'': 63–77.
* 1971 (with [[Leon Henkin]] and Donald Monk). ''Cylindric Algebras: Part I''. North-Holland.
* 1971 (with [[Leon Henkin]] and [[Donald Monk]]). ''Cylindric Algebras: Part I''. North-Holland.
* 1985 (with [[Leon Henkin]] and Donald Monk). ''Cylindric Algebras: Part II''. North-Holland.
* 1985 (with [[Leon Henkin]] and Donald Monk). ''Cylindric Algebras: Part II''. North-Holland.
* 1986. "What are Logical Notions?", Corcoran, J., ed., ''History and Philosophy of Logic 7'': 143–54.
* 1986. "What are Logical Notions?", Corcoran, J., ed., ''History and Philosophy of Logic 7'': 143–54.
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[[Category:1983 deaths]]
[[Category:1983 deaths]]
[[Category:20th-century American mathematicians]]
[[Category:20th-century American mathematicians]]
[[Category:20th-century American non-fiction writers]]
[[Category:20th-century American philosophers]]
[[Category:20th-century American philosophers]]
[[Category:20th-century American essayists]]
[[Category:20th-century American essayists]]
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[[Category:University of Warsaw alumni]]
[[Category:University of Warsaw alumni]]
[[Category:20th-century American male writers]]
[[Category:20th-century American male writers]]
[[Category:Corresponding Fellows of the British Academy]]
[[Category:Corresponding fellows of the British Academy]]

Latest revision as of 18:22, 15 December 2024

Alfred Tarski
Tarski in 1968
Born
Alfred Teitelbaum

(1901-01-14)January 14, 1901
DiedOctober 26, 1983(1983-10-26) (aged 82)
NationalityPolish, American
EducationUniversity of Warsaw (Ph.D., 1924)
Known for
Scientific career
FieldsMathematics, logic, formal language
Institutions
ThesisO wyrazie pierwotnym logistyki (On the Primitive Term of Logistic) (1924)
Doctoral advisorStanisław Leśniewski
Doctoral students
Other notable studentsEvert Willem Beth

Alfred Tarski (/ˈtɑːrski/, born Alfred Teitelbaum;[1][2][3] January 14, 1901 – October 26, 1983) was a Polish-American[4] logician and mathematician.[5] A prolific author best known for his work on model theory, metamathematics, and algebraic logic, he also contributed to abstract algebra, topology, geometry, measure theory, mathematical logic, set theory, and analytic philosophy.

Educated in Poland at the University of Warsaw, and a member of the Lwów–Warsaw school of logic and the Warsaw school of mathematics, he immigrated to the United States in 1939 where he became a naturalized citizen in 1945. Tarski taught and carried out research in mathematics at the University of California, Berkeley, from 1942 until his death in 1983.[6]

His biographers Anita Burdman Feferman and Solomon Feferman state that, "Along with his contemporary, Kurt Gödel, he changed the face of logic in the twentieth century, especially through his work on the concept of truth and the theory of models."[7]

Life

[edit]

Early life and education

[edit]

Alfred Tarski was born Alfred Teitelbaum (Polish spelling: "Tajtelbaum"), to parents who were Polish Jews in comfortable circumstances. He first manifested his mathematical abilities while in secondary school, at Warsaw's Szkoła Mazowiecka.[8] Nevertheless, he entered the University of Warsaw in 1918 intending to study biology.[9]

After Poland regained independence in 1918, Warsaw University came under the leadership of Jan Łukasiewicz, Stanisław Leśniewski and Wacław Sierpiński and quickly became a world-leading research institution in logic, foundational mathematics, and the philosophy of mathematics. Leśniewski recognized Tarski's potential as a mathematician and encouraged him to abandon biology.[9] Henceforth Tarski attended courses taught by Łukasiewicz, Sierpiński, Stefan Mazurkiewicz and Tadeusz Kotarbiński, and in 1924 became the only person ever to complete a doctorate under Leśniewski's supervision. His thesis was entitled O wyrazie pierwotnym logistyki (On the Primitive Term of Logistic; published 1923). Tarski and Leśniewski soon grew cool to each other, mainly due to the latter's increasing anti-semitism.[7] However, in later life, Tarski reserved his warmest praise for Kotarbiński, which was reciprocated.

In 1923, Alfred Teitelbaum and his brother Wacław changed their surname to "Tarski". The Tarski brothers also converted to Roman Catholicism, Poland's dominant religion. Alfred did so even though he was an avowed atheist.[10][11]

Career

[edit]

After becoming the youngest person ever to complete a doctorate at Warsaw University, Tarski taught logic at the Polish Pedagogical Institute, mathematics and logic at the university, and served as Łukasiewicz's assistant. Because these positions were poorly paid, Tarski also taught mathematics at the Third Boys’ Gimnazjum of the Trade Union of Polish Secondary-School Teachers (later the Stefan Żeromski Gimnazjum), a Warsaw secondary school, beginning in 1925.[12] Before World War II, it was not uncommon for European intellectuals of research caliber to teach high school. Hence until his departure for the United States in 1939, Tarski not only wrote several textbooks and many papers, a number of them ground-breaking, but also did so while supporting himself primarily by teaching high-school mathematics.[13] In 1929 Tarski married fellow teacher Maria Witkowska, a Pole of Catholic background. She had worked as a courier for the army in the Polish–Soviet War. They had two children; a son Jan Tarski, who became a physicist, and a daughter Ina, who married the mathematician Andrzej Ehrenfeucht.[14]

Tarski applied for a chair of philosophy at Lwów University, but on Bertrand Russell's recommendation it was awarded to Leon Chwistek.[15] In 1930, Tarski visited the University of Vienna, lectured to Karl Menger's colloquium, and met Kurt Gödel. Thanks to a fellowship, he was able to return to Vienna during the first half of 1935 to work with Menger's research group. From Vienna he traveled to Paris to present his ideas on truth at the first meeting of the Unity of Science movement, an outgrowth of the Vienna Circle. Tarski's academic career in Poland was strongly and repeatedly impacted by his heritage. For example, in 1937, Tarski applied for a chair at Poznań University but the chair was abolished to avoid assigning it to Tarski (who was undisputedly the strongest applicant) because he was a Jew.[16] Tarski's ties to the Unity of Science movement likely saved his life, because they resulted in his being invited to address the Unity of Science Congress held in September 1939 at Harvard University. Thus he left Poland in August 1939, on the last ship to sail from Poland for the United States before the German and Soviet invasion of Poland and the outbreak of World War II. Tarski left reluctantly, because Leśniewski had died a few months before, creating a vacancy which Tarski hoped to fill. Oblivious to the Nazi threat, he left his wife and children in Warsaw. He did not see them again until 1946. During the war, nearly all his Jewish extended family were murdered at the hands of the German occupying authorities.

Once in the United States, Tarski held a number of temporary teaching and research positions: Harvard University (1939), City College of New York (1940), and thanks to a Guggenheim Fellowship, the Institute for Advanced Study in Princeton (1942), where he again met Gödel. In 1942, Tarski joined the Mathematics Department at the University of California, Berkeley, where he spent the rest of his career. Tarski became an American citizen in 1945.[17] Although emeritus from 1968, he taught until 1973 and supervised Ph.D. candidates until his death.[18] At Berkeley, Tarski acquired a reputation as an astounding and demanding teacher, a fact noted by many observers:

His seminars at Berkeley quickly became famous in the world of mathematical logic. His students, many of whom became distinguished mathematicians, noted the awesome energy with which he would coax and cajole their best work out of them, always demanding the highest standards of clarity and precision.[19]

Tarski was extroverted, quick-witted, strong-willed, energetic, and sharp-tongued. He preferred his research to be collaborative — sometimes working all night with a colleague — and was very fastidious about priority.[20]

A charismatic leader and teacher, known for his brilliantly precise yet suspenseful expository style, Tarski had intimidatingly high standards for students, but at the same time he could be very encouraging, and particularly so to women — in contrast to the general trend. Some students were frightened away, but a circle of disciples remained, many of whom became world-renowned leaders in the field.[21]

Warsaw University Library – at entrance (seen from rear) are pillared statues of Lwów-Warsaw School philosophers (right to left) Kazimierz Twardowski, Jan Łukasiewicz, Alfred Tarski, Stanisław Leśniewski.

Tarski supervised twenty-four Ph.D. dissertations including (in chronological order) those of Andrzej Mostowski, Bjarni Jónsson, Julia Robinson, Robert Vaught, Solomon Feferman, Richard Montague, James Donald Monk, Haim Gaifman, Donald Pigozzi, and Roger Maddux, as well as Chen Chung Chang and Jerome Keisler, authors of Model Theory (1973),[22] a classic text in the field.[23][24] He also strongly influenced the dissertations of Adolf Lindenbaum, Dana Scott, and Steven Givant. Five of Tarski's students were women, a remarkable fact given that men represented an overwhelming majority of graduate students at the time.[24] However, he had extra-marital affairs with at least two of these students. After he showed another of his female student's[who?] work to a male colleague[who?], the colleague published it himself, leading her to leave the graduate study and later move to a different university and a different advisor.[25]

Tarski lectured at University College, London (1950, 1966), the Institut Henri Poincaré in Paris (1955), the Miller Institute for Basic Research in Science in Berkeley (1958–60), the University of California at Los Angeles (1967), and the Pontifical Catholic University of Chile (1974–75). Among many distinctions garnered over the course of his career, Tarski was elected to the United States National Academy of Sciences, the British Academy and the Royal Netherlands Academy of Arts and Sciences in 1958,[26] received honorary degrees from the Pontifical Catholic University of Chile in 1975, from Marseilles' Paul Cézanne University in 1977 and from the University of Calgary, as well as the Berkeley Citation in 1981. Tarski presided over the Association for Symbolic Logic, 1944–46, and the International Union for the History and Philosophy of Science, 1956–57. He was also an honorary editor of Algebra Universalis.[27]

Work in mathematics

[edit]

Tarski's mathematical interests were exceptionally broad. His collected papers run to about 2,500 pages, most of them on mathematics, not logic. For a concise survey of Tarski's mathematical and logical accomplishments by his former student Solomon Feferman, see "Interludes I–VI" in Feferman and Feferman.[28]

Tarski's first paper, published when he was 19 years old, was on set theory, a subject to which he returned throughout his life.[29] In 1924, he and Stefan Banach proved that, if one accepts the Axiom of Choice, a ball can be cut into a finite number of pieces, and then reassembled into a ball of larger size, or alternatively it can be reassembled into two balls whose sizes each equal that of the original one. This result is now called the Banach–Tarski paradox.[30]

In A decision method for elementary algebra and geometry, Tarski showed, by the method of quantifier elimination, that the first-order theory of the real numbers under addition and multiplication is decidable. (While this result appeared only in 1948, it dates back to 1930 and was mentioned in Tarski (1931).) This is a very curious result, because Alonzo Church proved in 1936 that Peano arithmetic (the theory of natural numbers) is not decidable. Peano arithmetic is also incomplete by Gödel's incompleteness theorem. In his 1953 Undecidable theories, Tarski et al. showed that many mathematical systems, including lattice theory, abstract projective geometry, and closure algebras, are all undecidable. The theory of Abelian groups is decidable, but that of non-Abelian groups is not.

While teaching at the Stefan Żeromski Gimnazjum in the 1920s and 30s, Tarski often taught geometry.[31] Using some ideas of Mario Pieri, in 1926 Tarski devised an original axiomatization for plane Euclidean geometry, one considerably more concise than Hilbert's.[32] Tarski's axioms form a first-order theory devoid of set theory, whose individuals are points, and having only two primitive relations. In 1930, he proved this theory decidable because it can be mapped into another theory he had already proved decidable, namely his first-order theory of the real numbers.

In 1929 he showed that much of Euclidean solid geometry could be recast as a second-order theory whose individuals are spheres (a primitive notion), a single primitive binary relation "is contained in", and two axioms that, among other things, imply that containment partially orders the spheres. Relaxing the requirement that all individuals be spheres yields a formalization of mereology far easier to exposit than Lesniewski's variant. Near the end of his life, Tarski wrote a very long letter, published as Tarski and Givant (1999), summarizing his work on geometry.[33]

Cardinal Algebras studied algebras whose models include the arithmetic of cardinal numbers. Ordinal Algebras sets out an algebra for the additive theory of order types. Cardinal, but not ordinal, addition commutes.

In 1941, Tarski published an important paper on binary relations, which began the work on relation algebra and its metamathematics that occupied Tarski and his students for much of the balance of his life. While that exploration (and the closely related work of Roger Lyndon) uncovered some important limitations of relation algebra, Tarski also showed (Tarski and Givant 1987) that relation algebra can express most axiomatic set theory and Peano arithmetic. For an introduction to relation algebra, see Maddux (2006). In the late 1940s, Tarski and his students devised cylindric algebras, which are to first-order logic what the two-element Boolean algebra is to classical sentential logic. This work culminated in the two monographs by Tarski, Henkin, and Monk (1971, 1985).[34]

Work in logic

[edit]

Tarski's student, Robert Lawson Vaught, has ranked Tarski as one of the four greatest logicians of all time — along with Aristotle, Gottlob Frege, and Kurt Gödel.[7][35][36] However, Tarski often expressed great admiration for Charles Sanders Peirce, particularly for his pioneering work in the logic of relations.

Tarski produced axioms for logical consequence and worked on deductive systems, the algebra of logic, and the theory of definability. His semantic methods, which culminated in the model theory he and a number of his Berkeley students developed in the 1950s and 60s, radically transformed Hilbert's proof-theoretic metamathematics. Around 1930, Tarski developed an abstract theory of logical deductions that models some properties of logical calculi. Mathematically, what he described is just a finitary closure operator on a set (the set of sentences). In abstract algebraic logic, finitary closure operators are still studied under the name consequence operator, which was coined by Tarski. The set S represents a set of sentences, a subset T of S a theory, and cl(T) is the set of all sentences that follow from the theory. This abstract approach was applied to fuzzy logic (see Gerla 2000).

In [Tarski's] view, metamathematics became similar to any mathematical discipline. Not only can its concepts and results be mathematized, but they actually can be integrated into mathematics. ... Tarski destroyed the borderline between metamathematics and mathematics. He objected to restricting the role of metamathematics to the foundations of mathematics.[37]

Tarski's 1936 article "On the concept of logical consequence" argued that the conclusion of an argument will follow logically from its premises if and only if every model of the premises is a model of the conclusion.[38] In 1937, he published a paper presenting clearly his views on the nature and purpose of the deductive method, and the role of logic in scientific studies.[29] His high school and undergraduate teaching on logic and axiomatics culminated in a classic short text, published first in Polish, then in German translation, and finally in a 1941 English translation as Introduction to Logic and to the Methodology of Deductive Sciences.[39]

Tarski's 1969 "Truth and proof" considered both Gödel's incompleteness theorems and Tarski's undefinability theorem, and mulled over their consequences for the axiomatic method in mathematics.

Truth in formalized languages

[edit]

In 1933, Tarski published a very long paper in Polish, titled "Pojęcie prawdy w językach nauk dedukcyjnych",[40] "Setting out a mathematical definition of truth for formal languages." The 1935 German translation was titled "Der Wahrheitsbegriff in den formalisierten Sprachen", "The concept of truth in formalized languages", sometimes shortened to "Wahrheitsbegriff". An English translation appeared in the 1956 first edition of the volume Logic, Semantics, Metamathematics. This collection of papers from 1923 to 1938 is an event in 20th-century analytic philosophy, a contribution to symbolic logic, semantics, and the philosophy of language. For a brief discussion of its content, see Convention T (and also T-schema).

A philosophical debate examines the extent to which Tarski's theory of truth for formalized languages can be seen as a correspondence theory of truth. The debate centers on how to read Tarski's condition of material adequacy for a true definition. That condition requires that the truth theory have the following as theorems for all sentences p of the language for which truth is being defined:

"p" is true if and only if p.

(where p is the proposition expressed by "p")

The debate amounts to whether to read sentences of this form, such as

"Snow is white" is true if and only if snow is white

as expressing merely a deflationary theory of truth or as embodying truth as a more substantial property (see Kirkham 1992).

Logical consequence

[edit]

In 1936, Tarski published Polish and German versions of a lecture, “On the Concept of Following Logically",[41] he had given the preceding year at the International Congress of Scientific Philosophy in Paris. A new English translation of this paper, Tarski (2002), highlights the many differences between the German and Polish versions of the paper and corrects a number of mistranslations in Tarski (1983).[41]

This publication set out the modern model-theoretic definition of (semantic) logical consequence, or at least the basis for it. Whether Tarski's notion was entirely the modern one turns on whether he intended to admit models with varying domains (and in particular, models with domains of different cardinalities).[citation needed] This question is a matter of some debate in the philosophical literature. John Etchemendy stimulated much of the discussion about Tarski's treatment of varying domains.[42]

Tarski ends by pointing out that his definition of logical consequence depends upon a division of terms into the logical and the extra-logical and he expresses some skepticism that any such objective division will be forthcoming. "What are Logical Notions?" can thus be viewed as continuing "On the Concept of Logical Consequence".[citation needed]

Logical notions

[edit]
Alfred Tarski at Berkeley

Tarski's "What are Logical Notions?" (Tarski 1986) is the published version of a talk that he gave originally in 1966 in London and later in 1973 in Buffalo; it was edited without his direct involvement by John Corcoran. It became the most cited paper in the journal History and Philosophy of Logic.[43]

In the talk, Tarski proposed demarcation of logical operations (which he calls "notions") from non-logical. The suggested criteria were derived from the Erlangen program of the 19th-century German mathematician Felix Klein. Mautner (in 1946), and possibly[clarification needed] an article by the Portuguese mathematician José Sebastião e Silva, anticipated Tarski in applying the Erlangen Program to logic.[citation needed]

The Erlangen program classified the various types of geometry (Euclidean geometry, affine geometry, topology, etc.) by the type of one-one transformation of space onto itself that left the objects of that geometrical theory invariant. (A one-to-one transformation is a functional map of the space onto itself so that every point of the space is associated with or mapped to one other point of the space. So, "rotate 30 degrees" and "magnify by a factor of 2" are intuitive descriptions of simple uniform one-one transformations.) Continuous transformations give rise to the objects of topology, similarity transformations to those of Euclidean geometry, and so on.[citation needed]

As the range of permissible transformations becomes broader, the range of objects one is able to distinguish as preserved by the application of the transformations becomes narrower. Similarity transformations are fairly narrow (they preserve the relative distance between points) and thus allow us to distinguish relatively many things (e.g., equilateral triangles from non-equilateral triangles). Continuous transformations (which can intuitively be thought of as transformations which allow non-uniform stretching, compression, bending, and twisting, but no ripping or glueing) allow us to distinguish a polygon from an annulus (ring with a hole in the centre), but do not allow us to distinguish two polygons from each other.[citation needed]

Tarski's proposal[which?] was to demarcate the logical notions by considering all possible one-to-one transformations (automorphisms) of a domain onto itself. By domain is meant the universe of discourse of a model for the semantic theory of logic. If one identifies the truth value True with the domain set and the truth-value False with the empty set, then the following operations are counted as logical under the proposal:

  1. Truth-functions: All truth-functions are admitted by the proposal. This includes, but is not limited to, all n-ary truth-functions for finite n. (It also admits of truth-functions with any infinite number of places.)
  2. Individuals: No individuals, provided the domain has at least two members.
  3. Predicates:
    • the one-place total and null predicates, the former having all members of the domain in its extension and the latter having no members of the domain in its extension
    • two-place total and null predicates, the former having the set of all ordered pairs of domain members as its extension and the latter with the empty set as extension
    • the two-place identity predicate, with the set of all order-pairs <a,a> in its extension, where a is a member of the domain
    • the two-place diversity predicate, with the set of all order pairs <a,b> where a and b are distinct members of the domain
    • n-ary predicates in general: all predicates definable from the identity predicate together with conjunction, disjunction and negation (up to any ordinality, finite or infinite)
  4. Quantifiers: Tarski explicitly discusses only monadic quantifiers and points out that all such numerical quantifiers are admitted under his proposal. These include the standard universal and existential quantifiers as well as numerical quantifiers such as "Exactly four", "Finitely many", "Uncountably many", and "Between four and 9 million", for example. While Tarski does not enter into the issue, it is also clear that polyadic quantifiers are admitted under the proposal. These are quantifiers like, given two predicates Fx and Gy, "More(x, y)", which says "More things have F than have G."
  5. Set-Theoretic relations: Relations such as inclusion, intersection and union applied to subsets of the domain are logical in the present sense.
  6. Set membership: Tarski ended his lecture with a discussion of whether the set membership relation counted as logical in his sense. (Given the reduction of (most of) mathematics to set theory, this was, in effect, the question of whether most or all of mathematics is a part of logic.) He pointed out that set membership is logical if set theory is developed along the lines of type theory, but is extralogical if set theory is set out axiomatically, as in the canonical Zermelo–Fraenkel set theory.
  7. Logical notions of higher order: While Tarski confined his discussion to operations of first-order logic, there is nothing about his proposal that necessarily restricts it to first-order logic. (Tarski likely restricted his attention to first-order notions as the talk was given to a non-technical audience.) So, higher-order quantifiers and predicates are admitted as well.[citation needed]

In some ways the present proposal is the obverse of that of Lindenbaum and Tarski (1936), who proved that all the logical operations of Bertrand Russell's and Whitehead's Principia Mathematica are invariant under one-to-one transformations of the domain onto itself. The present proposal is also employed in Tarski and Givant (1987).[44]

Solomon Feferman and Vann McGee further discussed Tarski's proposal[which?] in work published after his death. Feferman (1999) raises problems for the proposal and suggests a cure: replacing Tarski's preservation by automorphisms with preservation by arbitrary homomorphisms. In essence, this suggestion circumvents the difficulty Tarski's proposal has in dealing with a sameness of logical operation across distinct domains of a given cardinality and across domains of distinct cardinalities. Feferman's proposal results in a radical restriction of logical terms as compared to Tarski's original proposal. In particular, it ends up counting as logical only those operators of standard first-order logic without identity.[citation needed]

Vann McGee (1996) provides a precise account of what operations are logical in the sense of Tarski's proposal in terms of expressibility in a language that extends first-order logic by allowing arbitrarily long conjunctions and disjunctions, and quantification over arbitrarily many variables. "Arbitrarily" includes a countable infinity.[45]

Selected publications

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Anthologies and collections
  • 1986. The Collected Papers of Alfred Tarski, 4 vols. Givant, S. R., and McKenzie, R. N., eds. Birkhäuser.
  • Givant Steven (1986). "Bibliography of Alfred Tarski". Journal of Symbolic Logic. 51 (4): 913–41. doi:10.2307/2273905. JSTOR 2273905. S2CID 44369365.
  • 1983 (1956). Logic, Semantics, Metamathematics: Papers from 1923 to 1938 by Alfred Tarski, Corcoran, J., ed. Hackett. 1st edition edited and translated by J. H. Woodger, Oxford Uni. Press.[46] This collection contains translations from Polish of some of Tarski's most important papers of his early career, including The Concept of Truth in Formalized Languages and On the Concept of Logical Consequence discussed above.
Original publications of Tarski
  • 1930 Une contribution à la théorie de la mesure. Fund Math 15 (1930), 42–50.
  • 1930. (with Jan Łukasiewicz). "Untersuchungen uber den Aussagenkalkul" ["Investigations into the Sentential Calculus"], Comptes Rendus des seances de la Societe des Sciences et des Lettres de Varsovie, Vol, 23 (1930) Cl. III, pp. 31–32 in Tarski (1983): 38–59.
  • 1931. "Sur les ensembles définissables de nombres réels I", Fundamenta Mathematicae 17: 210–239 in Tarski (1983): 110–142.
  • 1936. "Grundlegung der wissenschaftlichen Semantik", Actes du Congrès international de philosophie scientifique, Sorbonne, Paris 1935, vol. III, Language et pseudo-problèmes, Paris, Hermann, 1936, pp. 1–8 in Tarski (1983): 401–408.
  • 1936. "Über den Begriff der logischen Folgerung", Actes du Congrès international de philosophie scientifique, Sorbonne, Paris 1935, vol. VII, Logique, Paris: Hermann, pp. 1–11 in Tarski (1983): 409–420.
  • 1936 (with Adolf Lindenbaum). "On the Limitations of Deductive Theories" in Tarski (1983): 384–92.
  • 1937. Einführung in die Mathematische Logik und in die Methodologie der Mathematik. Springer, Wien (Vienna).
  • 1994 (1941).[47][48] Introduction to Logic and to the Methodology of Deductive Sciences. Dover.
  • 1941. "On the calculus of relations", Journal of Symbolic Logic 6: 73–89.
  • 1944. "The Semantical Concept of Truth and the Foundations of Semantics," Philosophy and Phenomenological Research 4: 341–75.
  • 1948. A decision method for elementary algebra and geometry. Santa Monica CA: RAND Corp.[49]
  • 1949. Cardinal Algebras. Oxford Univ. Press.[50]
  • 1953 (with Mostowski and Raphael Robinson). Undecidable theories. North Holland.[51]
  • 1956. Ordinal algebras. North-Holland.
  • 1965. "A simplified formalization of predicate logic with identity", Archiv für Mathematische Logik und Grundlagenforschung 7: 61-79
  • 1969. "Truth and Proof", Scientific American 220: 63–77.
  • 1971 (with Leon Henkin and Donald Monk). Cylindric Algebras: Part I. North-Holland.
  • 1985 (with Leon Henkin and Donald Monk). Cylindric Algebras: Part II. North-Holland.
  • 1986. "What are Logical Notions?", Corcoran, J., ed., History and Philosophy of Logic 7: 143–54.
  • 1987 (with Steven Givant). A Formalization of Set Theory Without Variables. Vol.41 of American Mathematical Society colloquium publications. Providence RI: American Mathematical Society. ISBN 978-0821810415. Review
  • 1999 (with Steven Givant). "Tarski's system of geometry", Bulletin of Symbolic Logic 5: 175–214.
  • 2002. "On the Concept of Following Logically" (Magda Stroińska and David Hitchcock, trans.) History and Philosophy of Logic 23: 155–196.

See also

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References

[edit]
  1. ^ Alfred Tarski, "Alfred Tarski", Encyclopædia Britannica.
  2. ^ School of Mathematics and Statistics, University of St Andrews, "Alfred Tarski", School of Mathematics and Statistics, University of St Andrews.
  3. ^ "Alfred Tarski". Oxford Reference.
  4. ^ Gomez-Torrente, Mario (March 27, 2014). "Alfred Tarski - Philosophy - Oxford Bibliographies". Oxford University Press. Retrieved October 24, 2017.
  5. ^ Alfred Tarski, "Alfred Tarski", Stanford Encyclopedia of Philosophy.
  6. ^ Feferman A.
  7. ^ a b c Feferman & Feferman, p.1
  8. ^ Feferman & Feferman, pp.17-18
  9. ^ a b Feferman & Feferman, p.26
  10. ^ Feferman & Feferman, p.294
  11. ^ "Most of the Socialist Party members were also in favor of assimilation, and Tarski's political allegiance was socialist at the time. So, along with its being a practical move, becoming more Polish than Jewish was an ideological statement and was approved by many, though not all, of his colleagues. As to why Tarski, a professed atheist, converted, that just came with the territory and was part of the package: if you were going to be Polish then you had to say you were Catholic." Anita Burdman Feferman, Solomon Feferman, Alfred Tarski: Life and Logic (2004), page 39.
  12. ^ McFarland, Andrew; McFarland, Joanna; Smith, James T. (2014). Alfred Tarski: Early work in Poland — geometry and teaching. Birkhäuser/Springer, New York. p. 173. ISBN 978-1-4939-1473-9. MR 3307383.
  13. ^ McFarland, McFarland & Smith 2014, p. 319.
  14. ^ Feferman & Feferman (2004), pp. 239–242.
  15. ^ Feferman & Feferman, p. 67
  16. ^ Feferman & Feferman, pp. 102-103
  17. ^ Feferman & Feferman, Chap. 5, pp. 124-149
  18. ^ Robert Vaught; John Addison; Benson Mates; Julia Robinson (1985). "Alfred Tarski, Mathematics: Berkeley". University of California (System) Academic Senate. Retrieved 2008-12-26.
  19. ^ Obituary in Times, reproduced here
  20. ^ Gregory Moore, "Alfred Tarski" in Dictionary of Scientific Biography
  21. ^ Feferman
  22. ^ Chang, C.C., and Keisler, H.J., 1973. Model Theory. North-Holland, Amsterdam. American Elsevier, New York.
  23. ^ Alfred Tarski at the Mathematics Genealogy Project
  24. ^ a b Feferman & Feferman, pp. 385-386
  25. ^ Feferman & Feferman, pp. 177–178 and 197–201.
  26. ^ "Alfred Tarski (1902 - 1983)". Royal Netherlands Academy of Arts and Sciences. Retrieved 17 July 2015.
  27. ^ O'Connor, John J.; Robertson, Edmund F., "Alfred Tarski", MacTutor History of Mathematics Archive, University of St Andrews
  28. ^ Feferman & Feferman, pp. 43-52, 69-75, 109-123, 189-195, 277-287, 334-342
  29. ^ a b "Alfred Tarski". mathshistory.st-andrews.ac.uk. Retrieved 28 April 2023.
  30. ^ Katie Buchhorn (8 August 2012). "The Banach-Tarski Paradox". arXiv:2108.05714 [math.HO].
  31. ^ McFarland, McFarland & Smith 2014, Section 9.2: Teaching geometry, pp. 179–184.
  32. ^ Adam Grabowski. "Tarski's Geometry and the Euclidean Plane in Mizar" (PDF). ceur-ws.org. Retrieved 28 April 2023.
  33. ^ Tarski, Alfred; Givant, Steven (1999). "Tarski's System of Geometry". The Bulletin of Symbolic Logic. 5 (2): 175–214. doi:10.2307/421089. JSTOR 421089. S2CID 18551419.
  34. ^ "Tarski's convention-T and inductive definition?". Goodmancoaching. 22 May 2022. Retrieved 28 April 2023.
  35. ^ Vaught, Robert L. (Dec 1986). "Alfred Tarski's Work in Model Theory". Journal of Symbolic Logic. 51 (4): 869–882. doi:10.2307/2273900. JSTOR 2273900. S2CID 27153078.
  36. ^ Restall, Greg (2002–2006). "Great Moments in Logic". Archived from the original on 6 December 2008. Retrieved 2009-01-03.
  37. ^ Sinaceur, Hourya (2001). "Alfred Tarski: Semantic Shift, Heuristic Shift in Metamathematics". Synthese. 126 (1–2): 49–65. doi:10.1023/A:1005268531418. ISSN 0039-7857. S2CID 28783841.
  38. ^ Gómez-Torrente, Mario (1996). "Tarski on Logical Consequence". Notre Dame Journal of Formal Logic. 37. doi:10.1305/ndjfl/1040067321. S2CID 13217777.
  39. ^ "Introduction To Logic And To The Methodology Of Deductive Sciences". archive.org. Retrieved 28 April 2023.
  40. ^ Alfred Tarski, "POJĘCIE PRAWDY W JĘZYKACH NAUK DEDUKCYJNYCH", Towarszystwo Naukowe Warszawskie, Warszawa, 1933. (Text in Polish in the Digital Library WFISUW-IFISPAN-PTF) Archived 2016-03-04 at the Wayback Machine.
  41. ^ a b Tarski, Alfred (2002). "On the Concept of Following Logically". History and Philosophy of Logic. 23 (3): 155–196. doi:10.1080/0144534021000036683. S2CID 120956516.
  42. ^ Etchemendy, John (1999). The Concept of Logical Consequence. Stanford CA: CSLI Publications. ISBN 978-1-57586-194-4.
  43. ^ "History and Philosophy of Logic".
  44. ^ Németi, István (12 March 2014). "Alfred Tarski and Steven Givant. A formalization of set theory without variables. American Mathematical Society colloquium publications, vol. 41. American Mathematical Society, Providence1987, xxi + 318 pp". The Journal of Symbolic Logic. 55 (1): 350–352. doi:10.2307/2274990. JSTOR 2274990. Retrieved 28 April 2023.
  45. ^ McGee, Vann (1997). "Revision". Philosophical Issues. 8: 387–406. doi:10.2307/1523019. JSTOR 1523019. Retrieved 28 April 2023.
  46. ^ Halmos, Paul (1957). "Review: Logic, semantics, metamathematics. Papers from 1923 to 1938 by Alfred Tarski; translated by J. H. Woodger" (PDF). Bull. Amer. Math. Soc. 63 (2): 155–156. doi:10.1090/S0002-9904-1957-10115-3.
  47. ^ Quine, W. V. (1938). "Review: Einführung in die mathematische Logik und in die Methodologie der Mathematik by Alfred Tarski. Vienna, Springer, 1937. x+166 pp" (PDF). Bull. Amer. Math. Soc. 44 (5): 317–318. doi:10.1090/s0002-9904-1938-06731-6.
  48. ^ Curry, Haskell B. (1942). "Review: Introduction to Logic and to the Methodology of Deductive Sciences by Alfred Tarski" (PDF). Bull. Amer. Math. Soc. 48 (7): 507–510. doi:10.1090/s0002-9904-1942-07698-1.
  49. ^ McNaughton, Robert (1953). "Review: A decision method for elementary algebra and geometry by A. Tarski" (PDF). Bull. Amer. Math. Soc. 59 (1): 91–93. doi:10.1090/s0002-9904-1953-09664-1.
  50. ^ Birkhoff, Garrett (1950). "Review: Cardinal algebras by A. Tarski" (PDF). Bull. Amer. Math. Soc. 56 (2): 208–209. doi:10.1090/s0002-9904-1950-09394-x.
  51. ^ Gál, Ilse Novak (1954). "Review: Undecidable theories by Alfred Tarski in collaboration with A. Mostowsku and R. M. Robinson" (PDF). Bull. Amer. Math. Soc. 60 (6): 570–572. doi:10.1090/S0002-9904-1954-09858-0.

Further reading

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Biographical references
Logic literature
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