Kazimierz Ajdukiewicz

Ajdukiewicz was one ofPoland's most distinguished philosophers and logicians in the present century and he was among the most active members of the Lvov-Warsaw School, founded in 1895 by Kazimierz Twardowski inLvov. The dominant theme of Ajdukiewicz's thought was the problem of the dependence of our knowledge and conception of knowledge on language. His main contributions are in the field of logical syntax (with the theory of semantical categories) and in epistemology, with the so-called "radical conventionalism", a doctrine elaborated in the '30s, where, contrary to Poincaré and with reference to Eduard Le Roy, he claimed that there exist conceptual apparatuses which are not intertranslatable and that scientific knowledge grows through the replacement of one such conceptual apparatus by another. For these reasons he was a forerunner of the contemporary thesis regarding the incommensurability of scientific theories, supported by Kuhn, Feyerabend and others.
Kazimierz Ajdukiewicz was born in 1890 in Tarnopol (Galicia), in the territory of the Austrian Empire. Ajdukiewicz completed his secondary education inLvov and enrolled at University to read Philosophy, Mathematics and Physics. In 1912 he was awarded a Ph. D. degree in Philosophy on the basis of a thesis on Kant's philosophy of space. Among his university teachers inLvov were Kazimierz Twardowski in philosophy,Jan Lukasiewicz in logic and Waclaw Sierpinski in mathematics. Ajdukiewicz went toGöttingen University where David Hilbert was lecturing on the foundations of mathematics and Edmund Husserl on philosophy. A year later,however, he was conscripted into the Austrian army and served on the Italian front. Towards the end of World War I he joined the newly-formed Polish army, from which he was demobilized in 1920 with the rank of an artillery captain, to return to university life. He qualified as a university lecturer at Warsaw University in 1920 having submitted a dissertation entitledFrom the Methodology of Deductive Science (Lvov, 1921), a pioneer work with a deep influence on the development of logic in Poland: it contained formal (syntactical) definitions of such meta-logical concepts as "proof", "theorem", "consequence", "logical theorem", "logical consequence", thus introducing in Poland the structural method of defining these concepts. At that time he married Maria Twardowska, Kazimierz Twardowski's daughter; they subsequently had a son and a daughter.
Until the outbreak of World War II he was first lecturer and then professor of philosophy in the Universities of Lvov and Warsaw. In this period, roughly till 1936, he was concerned with the doctrine which he himself labeled Radical Conventionalism, resulting from an original pragmatic conception of language combined with a concept of intersubjective meaning, developed between 1929 and 1934. The retreat from this doctrine was accomplished in the second half of the thirties, but it seems that its fundamental ideas never ceased to fascinate Ajdukiewicz.
During World War II he continued to live with his family in Lvov. Forced under German occupation to earn his living as a clerk, he found time nevertheless to teach in clandestine Polish schools. After the war ended he accepted the Chair of the Methodology and Theory of Science (afterwards re-named the Chair of Logic) in the Faculty of Mathematical and Physical Sciences of the University of Poznan. In the years 1948-52 he was Rector of Poznan University. He left Poznan for Warsaw in 1955. As professor of Logic in the University of Warsaw and head of the Division of Logic in the Institute of Philosophy of the Polish Academy of Science, he continued until retirement in 1961, retaining, however, the latter post after retirement. Ajdukiewicz died in his sleep quite unexpectedly one night in 1963 of heart failure.
During the last years of his life he produced some of the most original articles of his career, clarifying and defending - against his own arguments put forward during the radical conventionalism period - the thesis of Moderate Empiricism (Logic and Experience, 1947) and, at the end of his life, the position of Radical Empiricism, according to which all knowledge consists of empirically revisable sentences. Moreover, towards the end of his life, he developed the outlines of a new research programme in epistemology and in the philosophy of language (The Problem of Empiricism and the Concept of Meaning, 1964).

Main works

A good bibliography of Ajdukiewicz's works is contained in the two volumes collecting nearly all the papers published in reviews: K. Ajdukiewicz, Jezyk i poznanie, PWN, Warszawa 1985, 2 voll., pp. 409-413.

Z metodologii nauk dedukcyjnych (From the Methodology of Deductive Science), Lwów 1921.

Glówne zasady metodologii nauki i logiki formalnej (Main principles of Metodology of Sciences and Formal Logic), Warszawa 1928

Problems and Theories of Philosophy (1949),Cambridge Univ. Press, London, 1973.

Pragmatic Logic (1965), Reidel, Dordrecht-Boston 1974.

The Scientific World-Prospective and other Essays (1931-1963), ed. by J. Giedymin, Reidel, Dordrecht 1978.

Taken from:
http://www.fmag.unict.it/PolPhil/Ajduk/Ajduk.html
http://main.amu.edu.pl/~pozn-stu/vols/ps40.html