Tarski’s 1944 Polemical Remarks and Naess’ “Experimental Philosophy”


Many of Tarski’s better known papers are either about or include lengthy discussions of how to properly define various concepts: truth, logical consequence, semantic concepts, or definability. In general, these papers identify two primary conditions for successful definitions: formal correctness and material (or intuitive) adequacy. Material adequacy requires that the concept expressed by the formal definition capture the intuitive content of truth. Our primary interest in this paper is to better understand Tarski’s thinking about material adequacy, and whether components of his view developed over time. More precisely, we are concerned with how Tarski’s understanding of the content of the common-sense, every-day usage of truth may have developed over time. We distinguish this concern from the character of the extensional criterion of adequacy Tarski proposes: that a materially adequate definition must entail all instances of Convention T. We will develop our reading of Tarski as follows: first, we will review the “Polemical Remarks,” focusing primarily on §§14 and 17, and Tarski’s references to Naess’ empirical research. Next, we will provide a summary and discussion of Naess’ work, especially his findings with respect to Tarski’s definition of truth and his research that suggests there is no single common or everyday concept of truth. Third, we will consider several possible objections to our interpretation of the Tarski–Naess dialectic. We will conclude that Tarski’s conception of material adequacy developed over time, potentially because of what he had learned through his interactions with Naess.

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  1. 1.

    Citing the common reader is not to focus upon them and their usage of “true”, etc., but to contrast the classical conception with the pragmatic conception, i.e., true as useful.

  2. 2.

    Jané (2006) and Betti (2008) have argued that what Tarski meant by the “common concept,” particularly of logical consequence, was common not in ordinary language and its usage by ordinary people but in axiomatics and its usage by specialists. We discuss this approach in §3 below.

  3. 3.

    Künne (2003) also notes the important role of the content of the conception of truth, for Tarski, as opposed to its formal implementation. What makes the formal definition a definition of “truth” (and not a mere stipulation) is that it is “obliged to capture, as far as possible, the meaning of 'true' in ordinary truth-ascriptions… It makes no sense to demand of a stipulative definition that it be materially adequate” (Künne 2003, 213).

  4. 4.

    See Crockett (1959) and Chapman (2008, Ch. 6) for discussion of Naess and his work.

  5. 5.

    It should be noted that this follows Naess’ own view, that empirical studies of non-philosophers cannot affect the formal elements of Tarski’s definition of truth (TCNP, §97).

  6. 6.

    As Patterson summarizes: “Lurking in the background of Tarski’s project, then, appears to be a rather articulate view of concepts, meanings, definitions, formalism, ordinary language, and related topics--a set of views in philosophy of logic, language, and to some extent mind. In order to understand Tarski’s work we need to know what these views were” (Patterson 2012, 16). One might disagree with Patterson’s interpretation by comparing what he said with what Tarski claims in fn. 4 of SCT. Regardless of which interpretation one supports, the purpose of introducing this summary is to show that a difference of interpretation is possible.

  7. 7.

    On the differences between CTFL and SCT, see Patterson 2012, Introduction and Ch. 8, and David 2008.

  8. 8.

    Tarski does not ascribe these statistics to Naess, but the context strongly suggests that these are Naess’ empirical findings since they align well with what he reports in TCNP.

  9. 9.

    We should take note that Tarski believes a “fixed and exact meaning” of “true,” like the one he proposes as the formally correct definition, “implies necessarily a certain deviation from the practice of everyday language” but not a complete rejection of ordinary usage (Tarski 1944, 360).

  10. 10.

    85.1 % of the participants were Norwegian, 8.7 % Austrian, 3.4 % Swede, and 3.2 % either German or English (TCNP, 44). 48 % of the respondents had completed grammar school, and 38.6 % of the respondents had completed a baccalaureate (TCNP, 45). Participants were aged 12 to 65 years old (CT, 46; TCNP, 44), and of Group-1 (the first 150 participants) 55 % were male and 45 % were female (TCNP, 45). The duration of the interviews lasted no less than 10 min, while 2 % carried on more than 10 h (CT, 44; TCNP, 44).

  11. 11.

    Naess reports on other formulations, too. D-formulations “substitute the word “true” for the word “right” or vice versa,” e.g., “what people with authority say is true” or “that it fulfills the requirements we ourselves make of that which we think is right.” M-formulations are those that are “concerned with moral standards,” e.g., “that conscience does not protest against it” or “the opposite of a lie” (TCNP 40, 57–60).

  12. 12.

    See Tarski (1944, 374n29). The relevant passages are found in TCNP, 144–148. The data most relevant to Tarski’s work was from class “E” questionnaires. This data was omitted from both TCNP and CT (Cf. TCNP, 22). Naess does briefly discuss some class “E” questionnaire data in Naess (1937/1938, 383). The fact that Tarski claims to be aware of results not published in TCNP clearly supports the view that Tarski had more than a merely passing familiarity with the empirical work done by Naess.

  13. 13.

    The follow-on item we mention in this paper asks study participants about whether they agree or disagree with a professional philosopher’s definition of truth. Other follow-on studies asked participants whether another participant’s definition sufficed for truth. (CT, 50f; TCNP, 125–153).

  14. 14.

    Naess did not take himself to be evaluating Tarski’s formal work. Rather, Naess was assessing whether something like a T-sentence was an expression of truth in the non-formal sense. Naess specifically writes in a footnote that “The “PAf 148” (Tarski) is not to be identified with the so-called “semantic notion of truth”. To construct this notion the method of formalization is essential. There is, however, a tendency to look at PAf 148 as a definition of non-formal truth. It was therefore included in our lists.” (TCNP, 148, fn1).

  15. 15.

    We should note here that some people might criticize Naess for not fully comprehending, or appreciating for that matter, the formal aspects of Tarski’s view. While such a criticism is plausible, Naess, at least in relevant portions of TCNP and CT, never went so far as to suggest his work revealed anything about formal elements of Tarski’s view of truth.

  16. 16.

    This result is of specific interest to some, like Tarski in CTFL, who claim that the common notion of truth is best understood as an expression of something like a correspondence theory.

  17. 17.

    Popper’s interpretation of the events is ambiguous. We do not know whether it was Neurath or Naess that “hoped” for Tarski’s semantic theory to be refuted. Perhaps Neurath despised Tarski’s semantic conception of truth so much so that he recommended Naess perform some experimental studies on the ordinary usage of truth to prove Tarski wrong (Cf. Neurath and Cohen 1946, 1973). Naess may have agreed, and if so, Naess aimed to refute Tarski’s theory of truth. On the surface, this is the argument of the passage; however, there is nothing appearing in Naess’ work that supports such an interpretation.

    An equally good interpretation of Popper’s passage would have it that Neurath hoped Naess would find empirical evidence refuting Tarski’s theory, without Naess taking up a position either for or against Tarski’s semantic conception (Cf. TCNP, 10–15). We know that Neurath rejected the formal terminology Tarski’s semantic conception of truth employed because he thought it would lead to “all kinds of metaphysical speculations,” something he and other members of the Vienna Circle despised (Mancosu 2010, 419). In Neurath’s view, Tarski’s generalizing to the ordinary usage of ‘truth’ from the formally correct definition was an illegitimate inferential maneuver that could be easily avoided if Tarski were instead to offer an anti-metaphysical and strictly empirically-based theory of truth independent of any formally correct condition (Ibid.). Therefore, it is entirely consistent with what Popper has said that it remain an open question whether Naess sought to undermine Tarski or not. There is some evidence that suggests the open question ought to be closed, and, in the beginning of this section, we provide reasons for thinking it ought to be closed.

  18. 18.

    The distinction between “intellectualist” and “pragmatic” accounts of truth is not discussed at length in Naess’ TCNP or CT, but in order to distinguish between the two he cites the debate regarding the notion of truth had between F.C.S. Schiller and Russell in Journal of Philosophy, Psychology, and Scientific Method (Naess CT, 57f).

  19. 19.

    These studies were a part of the research he completed in 1933 while writing his thesis, Diskusjonen omkring sannhetsbegrepet [The Discussion about the Concept of Truth], for the Masters degree at the University of Oslo. The empirical data later reappeared (in part) in his Ph.D. dissertation that was completed in 1936, Erkenntnis und wissenschaftliches Verhalten, and subsequently published in German (Naess 1936).

  20. 20.

    Also, we should note that Neurath’s interpretation of Naess’ data does not actually assert that Tarski’s semantic theory is refuted or disproved by Naess. Rather, the claim seems to be that Naess’ results challenge any claim to the effect that Tarski’s common concept is the only proper way to conceive the ordinary notion of truth. This is consistent with our interpretation.

  21. 21.

    Naess later sought to explain his disagreement with the empiricism of both Carnap and Neurath. His disagreement was directed against the “fundamental theses and trends in the Circle” that had been mistakenly understood by Neurath merely to be a “proposal for modifications which were already accepted in principle” (Naess 1968, 13f). Naess’ recollections of the events came from a paper he prepared between 1937 and 1939, which was not published until 1956 (Naess 2005a). In a review of the work, Eivind Storheim (1959) argued that Naess found Carnap’s view too myopic to accept citing as his chief complaint against Carnap a reluctance to accept that there ought to be empirical justification of the equivalence between expressions of natural language and of logic.

  22. 22.

    On an interesting note, Carnap seemingly endorses one of Naess’ later studies on the synonymity of expressions. Carnap writes: “Although there may be different opinions concerning some features of the various [empirical] procedures, it seems to me that [Naess’] book marks an important progress in the methodology of empirical meaning analysis for natural languages” (Carnap 1956, 241fn4). To be clear, however, Carnap sees that Naess’ work serves a very specific philosophic niche, one that likely does not affect various semantic concepts upon which he is focused.

  23. 23.

    We should note that a very interesting paper has spoken to how Carnapian explication can be used to “clarify” and “extend” experimental philosophy’s appeal. We believe that what we say here regarding Carnap’s methodological considerations for concept formation is compatible with theirs, cf. Shepherd and Justus (2015).

  24. 24.

    The unsurprising statistical results noted by Tarski in SCT §17 are suggestive. Even Tarski himself did not see Naess’ results as a refutation.

  25. 25.

    We would like to thank an anonymous referee for pointing out Jané and Betti’s important contribution to the historical debate regarding Tarski’s notion of “common concept.”

  26. 26.

    Furthermore, we would agree, in principle, with Patterson’s assessment of Jané’s (2006) work when Patterson writes: “The attraction of [Jané’s view] is obvious: since Tarski clearly doesn’t capture essential features of the ordinary notion, one proposes that he wasn’t trying to capture the ordinary notion. However, Tarski is trying to capture the ordinary notion--there are just too many passages in the article that say this, and capturing ordinary notions with expressions constrained by the structure of deductive theories is what he had been trying to do all along” (Patterson 2012, 220). This view is specifically supported by Carnap, who writes of Tarski’s view that “I [Carnap] assumed that he [Tarski] had in mind a syntactical definition of logical truth or provability. I was surprised when he said that he meant truth in the customary sense, including contingent factual truth” (Carnap 1963, 60). This last point is more fully developed in the account offered by Feferman (2008) who argues at length that Tarski always meant to offer an analysis of the customary sense of truth.

  27. 27.

    A defense of the Jané–Betti reading would require that there be some further basis for saying either that the common concept of consequence is not the more involved, less obvious, concept Tarski mentions in SCT or that the differences that Tarski mentions do not matter, i.e. that the more involved, less obvious, parts of consequence are inessential. This would clearly require a more developed account of what the essential versus inessential parts of the concept are like.

  28. 28.

    We thank an anonymous referee for providing us with this potential criticism of this discussion.

  29. 29.

    To be clear, we are not suggesting that there was a wholesale evolution of the formal criterion of material adequacy. Rather, we are claiming that Tarski found in Naess a reason to dwell on the question of the content of the concept that the formal criterion was supposed to track.

  30. 30.

    Patterson (2012) notes this passage and comments on its apparent tension with §14 of SCT and with the opening passages of CTFL. He reads this as evidence of Tarski’s dismissive attitude toward philosophy. We think it is further evidence of Tarski re-thinking the nature of the everyday usage of truth (see Patterson 2012, Ch. 8, especially 230f).

  31. 31.

    This is the substance of Patterson’s (2012) reading.


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We are grateful for comments we received on previous versions of this paper from thoughtful anonymous referees and audience members at national and international conferences. We would especially like to thank Dave Beisecker, Franz-Peter Griesmaier, Katarzyna Kijania-Placek, Marc Moffett, Kaija Mortensen, Jonathan Weinberg, and Cory Wright for helpful comments and extended conversations on the topic of this paper.

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Barnard, R., Ulatowski, J. Tarski’s 1944 Polemical Remarks and Naess’ “Experimental Philosophy”. Erkenn 81, 457–477 (2016). https://doi.org/10.1007/s10670-015-9750-1

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  • Semantic Conception
  • Common Concept
  • Everyday Language
  • Correct Definition
  • Ordinary Usage