The Model-Theoretic Argument

Many accept David Lewis's (1983) claim that, among the candidate meanings for our predicates, some are more natural than others -- they do better or worse at ``carving nature at its joints''. Call this claim predicate naturalism. Disagreement remains over whether the notion of naturalness extends ``beyond the predicate'' (à la Sider, 2011). Are the candidate meanings of logical vocabulary also more or less natural? Call this claim logical naturalism. -/- One motivation for predicate naturalism comes from its supposed ability (...) to help rebut various radical indeterminacy arguments associated with Hilary Putnam (1977, 1980, 1981). It does so in combination with a popular meta-semantic theory called reference magnetism. I argue that the same threats of Putnam-style radical indeterminacy rearise for proponents of predicate naturalism -- threats which logical naturalism helps rebuts. So, if we accept predicate naturalism because it helps fend off threats of indeterminacy, we should also accept logical naturalism. (shrink)

Dasgupta poses a serious challenge to realism about natural properties. He argues that there is no acceptable explanation of why natural properties deserve the value realists assign to them and are consequently absent of value. In response, this paper defines and defends an alternative non-explanatory account of normativity compatible with realism. Unlike Lewis and Sider, who believe it is sufficient to defend realism solely on realist terms, I engage with the challenge on unfriendly grounds by revealing a tu quoque. Dasgupta (...) and anti-realists face a similar challenge to that directed against realism: one that not only undermines the objection to realism by legitimising non-explanatory normativity but leaves them facing a significant dilemma. (shrink)

On a widespread naturalist view, the meanings of mathematical terms are determined, and can only be determined, by the way we use mathematical language—in particular, by the basic mathematical principles we’re disposed to accept. But it’s mysterious how this can be so, since, as is well known, minimally strong first-order theories are non-categorical and so are compatible with countless non-isomorphic interpretations. As for second-order theories: though they typically enjoy categoricity results—for instance, Dedekind’s categoricity theorem for second-order PA and Zermelo’s quasi-categoricity (...) theorem for second-order ZFC—these results require full second-order logic. So appealing to these results seems only to push the problem back, since the principles of second-order logic are themselves non-categorical: those principles are compatible with restricted interpretations of the second-order quantifiers on which Dedekind’s and Zermelo’s results are no longer available. In this paper, we provide a naturalist-friendly, non-revisionary solution to an analogous but seemingly more basic problem—Carnap’s Categoricity Problem for propositional and first-order logic—and show that our solution generalizes, giving us full second-order logic and thereby securing the categoricity or quasi-categoricity of second-order mathematical theories. Briefly, the first-order quantifiers have their intended interpretation, we claim, because we’re disposed to follow the quantifier rules in an open-ended way. As we show, given this open-endedness, the interpretation of the quantifiers must be permutation-invariant and so, by a theorem recently proved by Bonnay and Westerståhl, must be the standard interpretation. Analogously for the second-order case: we prove, by generalizing Bonnay and Westerståhl’s theorem, that the permutation invariance of the interpretation of the second-order quantifiers, guaranteed once again by the open-endedness of our inferential dispositions, suffices to yield full second-order logic. (shrink)

In this article, I have two aims. Firstly, I argue that Hilary Putnam's model theoretic indeterminacy argument against external realism and Saul Kripke's so-called Kripkensteinian argument against semantic realism have the same dialectical structure and the same conclusion---both force the opponent to face the same dilemma. Namely: either adopt meaning minimalism or postulate unobservable semantic facts. Secondly, I analyze more closely the first horn of the dilemma---meaning minimalism. This is the position according to which there are no truth conditions for (...) meaning-ascriptions. It has been suggested that this position is incoherent. However, I argue that there is a coherent option available for the meaning minimalist. As Crispin Wright has proposed, a coherent meaning minimalist has to adopt a structured truth-predicate with at least two levels: one is a minimal or a deflationary truth-predicate for a semantic discourse and the other, more substantial or objective truth-predicate for discourses like natural sciences. Subsequently, this leads to a position close to Huw Price's global expressivism. Thus, the ultimate dilemma that Putnam's and the Kripkensteinian argument establish is the following choice: either meaning minimalism with a structured two-level truth-predicate or robust realism regarding meaning. (shrink)

This is an extended intellectual obituary for Hilary Putnam.

Hilary Putnam’s BIV argument first occurred to him when ‘thinking about a theorem in modern logic, the “Skolem–Löwenheim Theorem”’ (Putnam 1981: 7). One of my aims in this paper is to explore the connection between the argument and the Theorem. But I also want to draw some further connections. In particular, I think that Putnam’s BIV argument provides us with an impressively versatile template for dealing with sceptical challenges. Indeed, this template allows us to unify some of Putnam’s most enduring (...) contributions to the realism/antirealism debate: his discussions of brains-in-vats, of Skolem’s Paradox, and of permutations. In all three cases, we have an argument which does not merely defeat the sceptic; it also shows us that we must reject some prima facie plausible philosophical picture. (shrink)

Tim Button explores the relationship between words and world; between semantics and scepticism. -/- A certain kind of philosopher – the external realist – worries that appearances might be radically deceptive. For example, she allows that we might all be brains in vats, stimulated by an infernal machine. But anyone who entertains the possibility of radical deception must also entertain a further worry: that all of our thoughts are totally contentless. That worry is just incoherent. -/- We cannot, then, be (...) external realists, who worry about the possibility of radical deception. Equally, however, we cannot be internal realists, who reject all possibility of deception. We must position ourselves somewhere between internal realism and external realism, but we cannot hope to say exactly where. We must be realists, for what that is worth, and realists within limits. -/- In establishing these claims, The Limits of Realism critically explores and develops several themes from Hilary Putnam’s work: the model-theoretic arguments; the connection between truth and justification; the brain-in-vat argument; semantic externalism; and conceptual relativity. The book establishes the continued significance of these topics for all philosophers interested in mind, logic, language, or the possibility of metaphysics. (shrink)

In his 1927 Analysis of Matter and elsewhere, Russell argued that we can successfully infer the structure of the external world from that of our explanatory schemes. While nothing guarantees that the intrinsic qualities of experiences are shared by their objects, he held that the relations tying together those relata perforce mirror relations that actually obtain (these being expressible in the formal idiom of the Principia Mathematica). This claim was subsequently criticized by the Cambridge mathematician Max Newman as true but (...) trivial, insofar as from a closed body of observations (or “Ramsey sentence”) one can always generate other equally-satisfactory networks of relations, provided they respect the original set’s cardinality. Since any model thus generated will be empirically adequate, “[t]he defence is therefore driven back from the fairly safe fictitious-real classification to the much less tenable ‘trivial’ and ‘important’” (Newman 1928). Given the definitional rigour afforded by the initial appeal to isomorphism (via one-to-one correspondences in extension), the received assessment, shared by Russell himself, is that retreating to a pragmatic adjudication would betoken a fatal blow. However, I suggest that reliance on “importance” can be avoided if we incorporate an impersonal criterion of diachronic precedence. When collecting observations, an ordinality emerges alongside the cardinality which gives that underived structure an irrevocable epistemological privilege. Hence, I argue that, all other things being equal, any construct parasitic on an antecedent theory ought to be regarded as inferior/dispensable, since it was generated by an algorithm lacking the world-involving pedigree of its host structure. (shrink)

Putnam famously attempted to use model theory to draw metaphysical conclusions. His Skolemisation argument sought to show metaphysical realists that their favourite theories have countable models. His permutation argument sought to show that they have permuted models. His constructivisation argument sought to show that any empirical evidence is compatible with the Axiom of Constructibility. Here, I examine the metamathematics of all three model-theoretic arguments, and I argue against Bays (2001, 2007) that Putnam is largely immune to metamathematical challenges.

Objection to Quine's argument for the inscrutability of reference. The proxy functions don't preserve the relations to experience, contrary to Quine's claims.

Hilary Putnams Biographie und philosophische Entwicklung spiegeln die Geschichte der angelsächsischen Philosophie in den letzten 40 Jahren. Beinahe ebenso lange hat Putnam diese Geschichte wesentlich beeinflußt und so kann John Passmore über Putnam schreiben: «Er ist die Geschichte der gegenwärtigen Philosophie im Umriß»1. In der vorliegenden Einleitung soll vor allem der Kontext dargestellt werden, in dem Putnam steht und aus dem heraus verständlich wird, was er philosophisch zu sagen hat. Dieser Kontext ist sicherlich ein Grund dafür, daß Putnam hierzulande noch (...) relativ wenig bekannt ist, während er in den USA häufig für den bedeutendsten aktiven Philosophen gehalten wird. Im Rahmen einer Skizze von Putnams philosophischer Entwicklung soll zudem eine vorläufige philosophiehistorische Einordnung versucht werden, auch wenn hier nicht der Ort für eine umfassende Kritik oder Darstellung sein kann: Die Einleitung muß auf recht elementarem Niveau bleiben und kann eine Lektüre der Texte natürlich nicht ersetzen. Da Putnams Werk sicherlich Teil einer Annäherung von ‹analytischer› und ‹kontinentaler› Philosophie ist, soll bei der Einführung in die hier übersetzten Texte schließlich deutlich werden, was Putnam nicht analytisch orientierten Lesern zu bieten hat. (shrink)

Einleitung - 1 Erklärung und Referenz (1973) - 2 Sprache und Wirklichkeit (1975) - 3 Was ist ‹Realismus›? (1975) - 4 Modelle und Wirklichkeit (1980) - 5 Referenz und Wahrheit (1980) - 6 Wie man zugleich interner Realist und transzendentaler Idealist sein kann (1980) - 7 Warum es keine Fertigwelt gibt (1982) - 8 Wozu die Philosophen? (1986) - 9 Realismus mit menschlichem Antlitz (1988/90) - 10 Irrealismus und Dekonstruktion (1992) - -/- Bibliographie der Schriften von Hilary Putnam - -/- (...) Literaturverzeichnis - Register -. (shrink)

Failure to recognize the "realistic" motivations for Putnam's commitment to internal realism has led to a widely shared misunderstanding of Putnam's arguments against metaphysical realism. Realist critics of these arguments frequently offer rebuttals that fail to confront his arguments. Simply put, Putnam's arguments --the brains in a vat argument as well as the model-theoretic argument -- are "reductios" that are intended to show that "metaphysical realism itself is not sufficiently realistic". If that claim can be substantiated then Putnam can go (...) on to argue that his own view is, by comparison, more realistic than metaphysical realism. (shrink)

The model-theoretic argument known as Putnam´s paradox threatens our notion of truth with triviality: Almost any world can satisfy almost any theory. Formal argument and intuition are at odds. David Lewis devised a solution according to which the very stucture of the world fixes how it is to be divided into elite classes which determine the reference of any true theory. Three claims are defended: Firstly, Lewis´ proposal must be completed by an account of successful referential intentions. Secondly, contrary to (...) Catherine Elgin´s criticism of Lewis, natural properties corresponding to elite classes may play a role in sound scientific inquiry. Thirdly, despite Bas van Fraassen´s objection that the sceptic cannot consistently maintain doubts about reference, there is a promising sceptical strategy of exploiting Putnam´s results which is answered by Lewis´ account. (shrink)