Toward the end of his life, Thomas Kuhn came to know the then new historical literature that substantially revised our understanding of Rudolf Carnap’s ideas. He was so taken with the emerging parallels between his own work and Carnap’s that he said “if I had known about it, if I had been into the literature at that level, I probably would never have written Structure.” Kuhn’s statement here is truly remarkable. There are, of course, both similarities and differences between Carnap and Kuhn. The similarities suggest that their two views are open to some of the same significant challenges and criticisms. But the differences suggest how each can help the other to meet the criticisms posed.

Recognition that people are divided by a common language is typically marked by a search for culprit ambiguities – but rarely so when name philosophers are involved, for whom continued talking past each other may seem the easier option.Whether the case of Carnap and Quine fits this profile is my quarry here. I begin with Quine’s conjecture that it was Neurath’s influence that made Carnap introduce the paragraphs into the Aufbau that promised, without elaboration, a conceptual genealogy on a physical basis. I argue that are good grounds to support Quine here. The analysis will be supplemented with remarks about later disagreements between Carnap and Neurath.

While a number of commentators have argued that Quine’s account of Carnap’s paper in terms of the category/subclass distinction is simply a misunderstanding of Carnap, this essay argues that it is not. Instead, Quine was correct to construe Carnap’s external questions of existence as all being category questions. Quine’s second claim – that answers to internal category questions of existence are trivial and analytic – was, however, incorrect. Here, this essay then dissents from a view of Ebbs, who has recently argued that Quine was right on both points. Instead, it is argued that epistemic considerations that support Quine’s first point undermine his second point.

W. V. Quine is famous for insisting that translation is indeterminate and Ludwig Wittgenstein widely believed, not least by Quine himself, to have been committed to the same view of translation. Taking Quine at his word, I explore why he would think those conversant with the later Wittgensteins remarks on meaning would take the argument about translation in Word and Object in stride. I argue that Quine and Wittgenstein are, for all their differences, reasonably regarded as battling a commonly held philosophical conception of the determinateness of translation. As I read Quine, he had it right when in later work he emphasized that he should be understood as mounting an argument against propositions, and he – and Wittgenstein – are on much firmer ground than usually supposed. Also in an Afterword I point out that Rudolf Carnap, arguably Wittgensteins most important successor and Quines most important predecessor, largely agreed with the argument I attribute to Quine and Wittgenstein in the body of the text, his reservations about many of their views notwithstanding.

While Quine is often taken to have broken the Viennese straitjacket of Logical Positivism, which rejected metaphysics, as an a priori but non-analytic, substantive discipline, allowing speculative metaphysics to be reborn, this paper argues against this. Instead, for all their much-discussed disagreements over analyticity and ontology, Quine shared Carnap’s more fundamental commitment to ‘scientific philosophy’: to the idea that legitimate philosophy is the work of handmaidens, site managers or accountants of science. Their primary role is to act to clarify, precisify and make explicit the methods and deliverances of science. The essay then brings Carnap and Quine to bear on more recent analytic trends towards metaphysics by specifically contrasting Carnap and Quine’s scientific philosophy with recent work by Timothy Williamson. This essay stresses Carnap and Quine’s considerable distance from Williamson; and that from Quine’s point of view as well as from Carnap’s, this recent ascendance of metaphysics will seem a departure from science without sufficient justification.

The arguments for the indeterminacy of Translation in Quine’s Word and Object (1960) form a turning point in his thinking. Quine may have started out as a disciple of Carnap’s, but in the 1940s and 1950s the most salient feature of Quine’s work is a deep asymmetry. Such extensional notions as reference and ontology are central and fully intelligible. Intensional notions such as analyticity and synonymy are not intelligible, and epistemic concerns are, in his published writing, not central. The arguments for the indeterminacy of translation undermine the asymmetry and initiate changes to the role of ontology and reference, to the status of simplicity, to Quine’s understanding of analyticity and synonymy, and to the character and centrality of his epistemology, ultimately including even a return to a two-tier epistemology. The changes do not amount to a wholesale rejection of earlier views, but exist uneasily alongside those previous views. In the aggregate, however, the changes were significant and brought Quine’s position back much closer to Carnap’s.

The Introduction provides an overview of the book and the individual chapters.

This essay examines the very beginning of Carnap and Quine’s philosophical relationship, focusing on Quine’s visit to Europe during the academic year 1932–33, during which he spent five weeks in Prague with Carnap. Verhaegh details what initiated Quine’s trip, the events leading up to his arrival in Prague, and finally the momentous philosophical exchange between Quine and Carnap that began there and that would carry on for the rest of Quine’s career, even after Carnap’s death in 1970.

This essay considers Carnap and Quine’s views on ontology. While both Carnap and Quine see their disagreement over the status of ontology as a legitimate philosophical undertaking as ultimately rooted in their disagreement over the analytic/synthetic distinction, it argues that this cannot be so since Quine comes to accept a notion of analyticity without changing his views on ontology. Instead, it is argued that the more fundamental point underlying the disagreement about the status of ontology is Carnaps advocacy of the Principle of Tolerance, which Quine never comes to accept.

This essay explores pragmatic aspects of Carnaps and Quines philosophy. It begins with a (schematic) characterization of pragmatism, pointing to recurring themes in the writings of leading American pragmatists, such as fallibilism, the social dimension of language and knowledge, the relation between belief and action, and the critique of skepticism, essentialism, foundationalism, and the fact/value dichotomy. It then examines aspects of Carnaps and Quines thinking that appear to be related (conceptually rather than historically) to pragmatism. Carnaps Principle of Tolerance and Quines critique of the analytic–synthetic distinction are primary examples, but there are others, such as their positions on scientific method, truth, and realism. Despite the similarities between Carnap and Quine emerging from this examination, the paper also identifies significant differences between their ways of understanding pragmatism. These differences, I suggest, are related to the difference between the European and American traditions regarding the meaning and use of the term pragmatism

This chapter examines the influence that the Logical Positivists had on Kuhn. Though he did not discuss their views extensively, he was reacting against a particular interpretation of their view.

A common account of the distinction between analytic and synthetic truths is that while the former are true solely in virtue of meaning, the latter are true also in virtue of the way of the world. Quine famously disputed this characterization, and his skepticism over the analytic/synthetic distinction has cast a long shadow. Against this skepticism, it is argued that the common account comes close to the truth, and that truthmaker theory offers the resources for providing a compelling account of the distinction that preserves the basic ideas behind it, and avoids the standard criticisms (from Quine, Harman, and Boghossian) facing the distinction. The thesis is that we can formulate an analytic/synthetic distinction in terms of the distinction between truths that require no ontological accounting whatsoever versus those that do. The ontological accounting required for analytic truths is trivial – any set of books will suffice. What distinguishes the synthetic truths is that they require some form of substantive ontological accounting.

This chapter distinguishes two broad conceptions of what the truthmaker project is all about. On the one hand, it might be thought of as a project of alethic explanation, that is, of offering systematic explanations as to why true truth-bearers are true (and why false truth-bearers are false). On the other hand, it might be a project of ontological accounting, of properly coordinating our beliefs and ontological inventories. The chapter adopts the latter approach, and defends it against the explanatory paradigm. This conception of truthmaking as ontological accounting then informs the conception of how we should think about the relation of truthmaking. The chapter begins by articulating the two perspectives on truthmaking, and defends the accounting approach over the explanatory conception. The accounting focus then enables an explaination of the relationship between truthmaking and ontological commitment, which is where the chapter ends.

This chapter demonstrates how thinking about truthmakers can bring some clarity to the ongoing debate concerning the ontological status of mathematical entities, and advances one position on the topic. It begins with what is nowadays the most familiar argument in the ontology of mathematics: the indispensability argument. Close inspection of it reveals that the notion of truthmaking is indeed playing a role, and that by thinking about indispensability and truthmaking in tandem, both ideas emerge with greater clarity. Focusing on indispensability will shed light on what the ontological stakes are in the overall debate, so the second section presents what is seen to be the most tenable ontological positions. It then offers a personal (rather deflationary) contribution to the truthmaking question about mathematics, and concludes by comparing and contrasting that view with a recent brand of mathematical trivialism.