Was Tarski the first to discuss the logically of the truth predicate?

Question

Tarski famously discussed, formally, the logically of the truth predicate, in The Concept of Truth in Formalised Languages (1935).

Was he the first to do so?

Thank you for any scholarly reference.

Answer 1

Rudolf Carnap: not exactly a "first discoverer" but at least a "contemporaneous researcher".

Tarski points to Carnap as “the first to attempt to formulate a precise definition of the proper concept of consequence”.

The references is to:

• Abriss der Logistik, mit besonderer Berücksichtigung der Relationstheorie und ihrer Anwendungen (1929).

In the course of his correspondence with other logicians (a 1934 post card to Kazimierz Twardowski), Taski discusses also Carnap’s new book Die logische Syntax der Sprache (1934).

See English translation (1937), page 216:

This contradiction only arises when the predicates ‘true’ and ‘false’ referring to sentences in a language S are used in S itself. On the other hand, it is possible to proceed without incurring any contradiction by employing the predicates ‘true (in S1)’ and ‘false (in S1)’ in a syntax of S1 which is not formulated in S1 itself but in another language S2. [...] A theory of this kind formulated in the manner of a syntax would nevertheless not be genuine syntax. For truth and falsehood are not proper syntactical properties; whether a sentence is true or false cannot generally be seen by its design, that is to say, by the kinds and serial oder of its symbols.

See Monika Gruber, Alfred Tarski and The Concept of Truth in Formalized Languages (Springer, 2016).

Following Carnap's recollections (in his Intellectual Autobiography (1963)):

Even before the publication of Tarski’s article I had realized, chiefly in conversations with Tarski and Gödel, that there must be a mode, different from the syntactical one [ref. to Hilbert's metamathematics] in which to speak about language. Since it is obviously admissible about facts, and, on the other hand, notwithstanding Wittgenstein [ref.to Wittgenstein's Tractatus], about expressions of a language, it cannot be inadmissible to do both in the same language.

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The German version of Alfred Tarski’s monograph has been published in 1935 under the title “Der Wahrheitsbegriff in den formalisierten Sprachen”

It is a translation of the Polish original written at the end of the 1920s and the beginning of the 1930s; March 21, 1931, it was presented in 1931 by Jan Łukasiewicz to the Warsaw Scientific Society and published in 1933 under the title “Pojęcie prawdy w językach nauk dedukcyjnych.”

See also: Tarski, Neurath, and Kokoszynska on the Semantic Conception of Truth, into Paolo Mancosu, The Adventure of Reason. Interplay Between Philosophy of Mathematics and Mathematical Logic 1900-1940 (Oxford UP, 2010).