This article examines Hilary Putnam's work in the philosophy of mathematics and - more specifically - his arguments against mathematical realism or objectivism. These include a wide range of considerations, from Gödel's incompleteness-theorem and the limits of axiomatic set-theory as formalised in the Löwenheim-Skolem proof to Wittgenstein's sceptical thoughts about rule-following, Michael Dummett's anti-realist philosophy of mathematics, and certain problems – as Putnam sees them – with the conceptual foundations of Peano arithmetic. He also adopts a thought-experimental approach – a (...) variant of Descartes' dream scenario – in order to establish the in-principle possibility that we might be deceived by the apparent self-evidence of basic arithmetical truths or that it might be ‘rational’ to doubt them under some conceivable set of circumstances. Thus Putnam assumes that mathematical realism involves a self-contradictory ‘Platonist’ idea of our somehow having quasi-perceptual epistemic ‘contact’ with truths that in their very nature transcend the utmost reach of human cognitive grasp. On this account, quite simply, ‘nothing works’ in philosophy of mathematics since wecan either cling to that unworkable notion of objective truth or abandon mathematical realism in favour of a verificationist approach that restricts the range of admissible statements to those for which we happen to possess some means of proof or ascertainment. My essay puts the case, conversely, that these hyperbolic doubts are not forced upon us but result from a false understanding of mathematical realism – a curious mixture of idealist and empiricist themes – which effectively skews the debate toward a preordained sceptical conclusion. I then go on to mount a defence of mathematical realism with reference to recent work in this field and also to indicate some problems – as I seethem – with Putnam's thought-experimental approach as well ashis use of anti-realist arguments from Dummett, Kripke, Wittgenstein, and others. (shrink)

The article addresses the works of three 19th-century philosophers: Herbart, Bolzano and Lotze. Despite their differences, i will analyze two essential features they share: their refusal to psychologism as the radicalization of psychology as the ultimate source of philosophy , and the positing of an ideal ‘reality’, independent from both sensibility and the mental and linguistic dimensions, upon which the refusal to psychologism is founded . As a conclusion, i will show how, according to these authors, this platonic, ideal background (...) constitutes the very foundation of every meaningful thought. (shrink)

Amongst those views sometimes attributed to the later Wittgenstein are included both a deflationary theory of truth, as well as a non-factualism about certain regions of discourse. Evidence in favor of the former attribution, it is thought, can be found in Wittgenstein’s apparent affirmation of the basic definitional equivalence of ‘p’ is true and p in §136 of his Philosophical Investigations. Evidence in favor of the latter attribution, it might then be presumed, can be found in the context of the (...) so-called ‘private language argument’, wherein Wittgenstein provides an expressivist treatment of first-person present tense sensation utterances. In this paper, by contrast, I will argue that Wittgenstein’s later philosophy is best understood as endorsing neither a non-factualism about sensation utterances, nor a deflationism about truth. Wittgenstein should instead be understood as offering a ‘mixed’ view of sensation utterances according to which some while not others are apt for expressivist treatment. Moreover, he should be thought of as identifying truth-conditions with semantic ‘correctness-conditions’, and thus truth with semantic ‘assertibility’. (shrink)

A comparison is given between two conditions used to define logical constants: Belnap's uniqueness and Hacking's deducibility of identicals. It is shown that, in spite of some surface similarities, there is a deep difference between them. On the one hand, deducibility of identicals turns out to be a weaker and less demanding condition than uniqueness. On the other hand, deducibility of identicals is shown to be more faithful to the inferentialist perspective, permitting definition of genuinely proof-theoretical concepts. This kind of (...) analysis is driven by exploiting the Curry–Howard correspondence. In particular, deducibility of identicals is shown to correspond to the computational property of eta expansion, which is essential in the characterization of propositional identity. (shrink)

In this paper I provide a theory of the speech act of assertion according to which assertion is a species of joint action. In doing so I rely on a theory of joint action developed in more detail elsewhere. Here we need to distinguish between the genus, joint action, and an important species of joint action, namely, what I call joint epistemic action. In the case of the latter, but not necessarily the former, participating agents have epistemic goals, e.g., the (...) acquisition of knowledge. It is joint epistemic action that assertion is a species of. (shrink)

Using Buddhist thought, explores and challenges the philosophy of Jean-Paul Sartre.

Strictly intuitionistic inferences are employed to demonstrate that three conditions—the existence of Brouwerian weak counterexamples to _Test_, the recognition condition, and the _BHK_ interpretation of the logical signs—are together inconsistent. Therefore, if the logical signs in mathematical statements governed by the recognition condition are constructive in that they satisfy the clauses of the _BHK_, then every relevant instance of the classical principle _Test_ is true intuitionistically, and the antirealistic critique of conventional logic, once thought to yield such weak counterexamples, is (...) seen, in this instance, to fail. (shrink)

Rejectivism is one of the most influential embodiments of pragmatism within contemporary philosophy of logic, advancing an explanation of the meaning of a logical notion, negation, in terms of the speech act of denial. This paper offers a challenge to rejectivism by proposing that in virtue of explaining negation in terms of denial, the rejectivist ought to be able to explain the concept of contradiction partially in terms of denial. It is argued that any failure to achieve this constitutes an (...) explanatory failure on the part of rejectivism, and reasons are then provided to doubt that the challenge can be successfully met. (shrink)

Donald Davidson infamously claims that belief is in its nature veridical, and that skepticism is for this reason fundamentally incoherent. To those who take the issue of external world skepticism seriously, Davidson's arguments may seem to involve a conjuring trick. In particular, his invocation of an ‘omniscient interpreter’, whose intelligibility supposedly ensures that our beliefs must be largely true, has the air of incense and lantern-rubbing about it. Davidson's claim has received considerable critical response in the literature, almost all of (...) it negative. In my view, some commentators have indeed lit on a critical and controversial lemma in Davidson's argument, but this basic result has been obscured by being presented amidst an array of other criticisms that simply make no sense from a Davidsonian point of view. The aim of this paper is to clear away some of the confusion that stands in the way of a more productive evaluation of Davidson's important claim. (shrink)

This paper aims to renew the “deflationary” interpretation of Ramsey’s theory of truth, with respect to his declared “pragmatist tendency,” which was not completely developed due to his premature death. This aim is not only historical-philosophical, but also exquisitely theoretical, since the mediation of pragmatism allowed Ramsey to achieve an original synthesis among different philosophical instances. In order to show this, I pay attention to the debate between Ramsey and some spokespeople of the leading British philosophical traditions at the beginning (...) of the twentieth century (especially Neo-idealism, Neo-empiricism, and Oxford Realism), through which it will stand out how Ramsey’s logical analysis of the truth predicate was embedded within a wider theoretical context, involving a pragmatic theory of knowledge and even a “general psychological theory.” Indeed, the truth of a belief will be defined in relation to mental factors, in so far as they involve a successful disposition to behave. (shrink)

On the background of the later opposition between realism and anti-realism, and with special attention to the overlapping of reality and logos, an examination of Aristotle’s way of answering to the...

We are logical pluralists who hold that the right logic is dependent on the domain of investigation; different logics for different mathematical theories. The purpose of this article is to explore the ramifications for our pluralism concerning normativity. Is there any normative role for logic, once we give up its universality? We discuss Florian Steingerger’s “Frege and Carnap on the Normativity of Logic” as a source for possible types of normativity, and then turn to our own proposal, which postulates that (...) various logics are constitutive for thought within particular practices, but none are constitutive for thought as such. (shrink)

European Journal of Philosophy, Volume 30, Issue 3, Page 1010-1027, September 2022.

This is a review of 'The Facts in Logical Space' by Jason Turner.

It seems to be impossible to draw metaphysical conclusions about the world merely from our concepts or our language alone. After all, our concepts alone only concern how we aim to represent the world, not how the world in fact is. In this paper I argue that this is mistaken. We can sometimes draw substantial metaphysical conclusions simply from thinking about how we represent the world. But by themselves such conclusions can be flawed if the concepts from which they are (...) drawn are themselves flawed. I propose that we can overcome these limitations by focusing on a special class of concepts: inescapable concepts. Combining arguments about what the world is like from considerations about our concepts alone, together with an argument that the relevant concepts are inescapable, leads to a novel method for metaphysics, which is broadly neo-Kantian. (shrink)

A remembrance of Dummett's work on philosophy of mathematcis.

In this paper it is argued that the understanding of Brouwer as replacing truth conditions with assertability or proof conditions, in particular as codified in the so-called Brouwer-Heyting-Kolmogorov Interpretation, is misleading and conflates a weak and a strong notion of truth that have to be kept apart to understand Brouwer properly: truth-as-anticipation and truth- in-content. These notions are explained, exegetical documentation provided, and semi-formal recursive definitions are given.

In Hard Truths Elijah Millgram argues that ‘partial truth’ is pervasive and for that reason bivalence 1 may rarely be assumed. As classical logic assumes bivalence, and inferences from partial truths to partial truths are central to our thinking, classical logic rarely has application, the argument continues. And so we must develop an account of inference from partial truths to partial truths; as well, our metaphysics must be revised. While the novel positions of Hard Truths 2 raise many interesting challenges, (...) my focus is limited to offering an alternative to Millgram’s account of predication and to exploring some issues raised by his appeal to ‘fit’ in his definitions of truth and partial truth. 1. Introduction to partial truth Millgram defines truth and partial truth in terms of fit, as follows: Advancing a claim as fully true demands complete fit; assessing a claim as partially true allows for slack … but only so much of it. Claims are said to completely fit, slackly fit or not fit, the world, in §6.3. But, the word ‘fit’ is first introduced in §1.2, and it is experience or proto-experience, that fits into moulds provided by claims, thoughts, sentences and predicates. I won’t dwell on which fits what, 3 but on the notion of a ‘complete fit’ and the contrast with a ‘slack fit’; this discussion leads me to ponder the clarity and implications of appealing to these notions in definitions like the above. Millgram’s explanation of fit comes in the context of his account of predication, according to which, most predicates do not quite apply. It’s this that is primarily responsible for his promotion of partial truth. I sketch an alternative account of language whereby predicates do apply because language has come to life as a constituent of the things we do: …. (shrink)

Logical pluralists are committed to the idea of a neutral metalanguage, which serves as a framework for debates in logic. Two versions of this neutrality can be found in the literature: an agreed upon collection of inferences, and a metalanguage that is neutral as such. I discuss both versions and show that they are not immune to Quinean criticism, which builds on the notion of meaning. In particular, I show that the first version of neutrality is sub-optimal, and hard to (...) reconcile with the theories of meaning for logical constants, and the second version collapses mathematically, if rival logics, as object languages, are treated with charity in the metalanguage. I substantiate by proving a collapse theorem that generalizes familiar results. Thus, the existence of a neutral metalanguage cannot be taken for granted, and meaning-invariant logical pluralism might turn out to be dubious. (shrink)

A position that has been called ‘classical indeterminism’ has recently been developed in order to model vagueness: this approach appeals to an object-language ‘determinately’ operator, the semantics of which are defined in such a way as to preserve the principle of bivalence. I suggest that a prominent argument against this strategy, which I call the Field–Williamson argument, fails. The classical indeterminist position in its general form was anticipated by the Aristotelian commentators in their discussions of Aristotle’s famous ‘sea battle’ passage (...) concerning future contingency. But I maintain that, ironically enough, the strategy is less happily applied in this case, where a version of the Field–Williamson argument succeeds. (shrink)

Call the epistemological grounds on which we rationally should determine our ontological (or alethiological) commitments regarding an entity its arbiter of existence (or arbiter of truth). It is commonly thought that arbiters of existence and truth can be provided by our practices. This paper argues that such views have several implications: (1) the relation of arbiters to our metaphysical commitments consists in indispensability, (2) realist views about a kind of entity should take the kinds of practices providing that entity’s arbiters (...) to align with respect to their metaphysical dependencies, (3) if realists take a kind of practice to provide grounds on which to affirm the existence of a kind of entity, they should turn to those same grounds when seeking to provide an epistemology of the relevant domain. (shrink)

William Lynch has provided an informed and probing critique of my embrace of the post-truth condition, which he understands correctly as an extension of the normative project of social epistemology. This article roughly tracks the order of Lynch’s paper, beginning with the vexed role of the ‘normative’ in Science and Technology Studies, which originally triggered my version of social epistemology 35 years ago and has been guided by the field’s ‘symmetry principle’. Here the pejorative use of ‘populism’ to mean democracy (...) is highlighted as a failure of symmetry. Finally, after rejecting Lynch’s appeal to a hybrid Marxian–Darwinism, Carl Schmitt and Thomas Hobbes are contrasted en route to what I have called ‘quantum epistemology’. (shrink)

Em sua obra, Robert Brandom apresenta uma teoria expressivista da lógica. Segundo o autor, a lógica tem o papel expressivo de tornar explı́citas as relações inferenciais implı́citas em nossas práticas linguı́sticas. Estas relações inferenciais conferem conteúdo aos conceitos. Neste artigo, exploraremos a tese de que o expressivismo lógico de Brandom é uma teoria antirrealista acerca da lógica. Realistas lógicos costumam defender a existência independente de fatos lógicos em relação a nossas práticas cognitivas e linguı́sticas, de modo que a lógica, uma (...) vez que seria capaz de representar estes fatos, descreveria verdadeiramente a estrutura da realidade. Por contraste, antirrealistas lógicos não se comprometem com a existência independente de fatos lógicos para entenderem a natureza da lógica. Em contraste com uma visão realista, mostramos que o antirrealismo de Brandom tem como consequências uma ontologia simples e econômica e a fundação de uma alternativa pragmatista para se examinar a normatividade da lógica, o fenômeno da pluralidade de lógicas rivais e a natureza de nossa racionalidade. (shrink)

One major difficulty confronting attempts to clarify the epistemological and ontological status of abstract objects is determining the sense, if any, in which such entities may be characterised as mind and language independent. Our contention is that the tolerant reductionist position of Michael Dummett can be strengthened by drawing on Husserl's mature account of the constitution of ideal objects and mathematical objectivity. According to the Husserlian position we advocate, abstract singular terms pick out weakly mind-independent sedimented meaning-contents. These meaning-contents serve (...) as the ‘thin’ referents of abstract singular terms, but are ultimately founded in prior acts of meaning-constitution. (shrink)

This paper can be read as an attempt at providing philosophical foundations to linear logic. The only plausible form of philosophical antirealism deals with practical feasibility rather than with effectivity in principle. The very notion of recognizability is ambiguous, audit has to be considered from a stricter perspective than currently done. The intuitionistic assertability conditions are to be reinforced. This change requires a move towards a frame in which the circumstances of the application of a logical rule can be specified. (...) Gentzen's sequential calculi provide such a frame, when some structural rules have been removed or limited. (shrink)

The paper is a defense of a strict form of anti-realism, competing the "in principle" form defended by Michael Dummett. It proposes to ground anti-realism on the basis of two principles ("immanence" and "implicitness") and to develop the consequences of these principles in the light of sub-structural logics.

We review the current situation in the philosophy of time, partly to investigate Michael Dummett’s complaint that the philosophy of physics has become too specialized and technical to be able to communicate with mainstream philosophy. We conclude that the situation in this case is different: there is no special difficulty of intelligibility---the obstacle for communication between science and philosophy here is rather that what physics, or science in general, tells us is prima facie in conflict with common sense and intuition. (...) We argue that this difficulty is indeed prima facie: on closer inspection it appears that the scientific B-theory may explain our intuition better than the A-theory, even though the latter at first sight seems to completely mirror our direct experience. (shrink)

Questions embedded under responsive predicates and definite descriptions both give rise to a variety of phenomena which can be grouped under the term plurality effects: quantificational variability, cumulativity, and homogeneity effects. This similarity has not gone unnoticed, and many proposals have taken inspiration in theories of definite plurals to account for these effects with embedded questions. Recently these phenomena have received less attention, as the field has focused on the so-called intermediate exhaustive reading of embedded questions instead, after Spector called (...) into question the traditional dichotomy between weak and strong exhaustive readings. As a result, the intermediate exhaustive reading has been accounted for at the expense of empirical coverage in other areas. In this paper, I propose a modular theory which derives the currently much discussed exhaustive readings without giving up the rich semantics necessary to account for plurality effects. My account of quantificational variability, cumulativity, and homogeneity effects builds on recent work on these phenomena in the nominal domain by adopting a categorial approach to embedded questions, while the strong and intermediate exhaustive readings are implemented using an independent strengthening mechanism suggested in Klinedinst and Rothschild :1–23, 2011). The resulting theory not only recovers important results on plurality effects; it offers new, simple solutions for some puzzles presented in George :166–177, 2013) and Paillé and Schwarz Proceedings of WCCFL 36, vol 36, Cascadilla Proceedings Project, Somerville, 2018), naturally derives readings that had been postulated in previous literature, makes correct predictions in many unexplored cases, and is compatible with recent results in psycholinguistics. In the last sections I justify my assumptions and show how possible limitations I inherit from the theories I build on can be accommodated under standard assumptions. (shrink)

Some platonists truly agonize over the ontological commitments which their platonism demands of them. Peter van Inwagen, for example, confesses candidly,I am happy to admit that I am uneasy about believing in the existence of ‘causally irrelevant’ objects. The fact that abstract objects, if they exist, can be neither causes or [sic] effects is one of the many features of abstract objects that make nominalism so attractive. I should very much like to be a nominalist, but I don't see how (...) to be one …. (shrink)

The present paper is intended to analyse from a theoretical point of view the relationships between natural language and idiolects in the context of communication by means of the Davidson–Dummett controversy on the nature of language. I will explore from a pragmatic point of view the reliability of an alternative position inspired by the recent literalism/contextualism debate in philosophy of language in order to overcome some limitations of Dummett’s and Davidson’s perspectives on language, idiolects and communication.

The first half of Mark Quentin Gardiner’s recent book, Semantic Challenges to Realism: Dummett and Putnam, is a sustained, systematic, and, for the most part, novel attempt to demolish the case against semantic realism instigated by Michael Dummett. In this article I reply on the anti-realist’s be-half. I aim to demonstrate that none of Gardiner’s main anti-Dummettian arguments are successful, and moreover that his errors are, in the main, consequences of serious misconstruals of vital aspects of the semantic realist and (...) anti-realist positions. (shrink)

The Logocratic Method, and the Logocratic theory that underwrites it, provide a philosophical explanation of three purposes or goals that arguers have for their arguments: to make arguments that are internally strong, or that are dialectically strong, or that are rhetorically strong. This article presents the basic terms and methods of Logocratic analysis and then uses a case study to illustrate the Logocratic explanation of arguments. Highlights of this explanation are: the use of a virtue framework to explicate the three (...) strengths and weaknesses of arguments that are of greatest interest to arguers in many contexts, the Logocratic explication of the structure of abduction generally and of legal abduction specifically, the concept of a system of arguments, and the concept of the dynamic interactive virtue of arguments—a property of systems of arguments in which the system of arguments as a whole is as virtuous as are the component arguments that comprise the system. This is especially important since, according to Logocratic theory, some arguments, such as abduction and analogical argument, are themselves comprised of different logical forms. (shrink)

_ Source: _Page Count 25 The familiar challenges to historiographical knowledge turn on epistemological concerns having to do with the unobservability of historical events, or with the problem of establishing a sufficiently strong inferential connection between evidence and the historiographical claim one wishes to convert from a true belief into knowledge. This paper argues that these challenges miss a deeper problem, viz., the lack of obvious truth-makers for historiographical claims. The metaphysical challenge to historiography is that reality does not appear (...) to co-operate in our cognitive endeavours by providing truth-makers for claims about historical entities and events. Setting out this less familiar, but more fundamental, challenge to the very possibility of historiography is the first aim of this paper. The various ways in which this challenge might be met are then set out, including ontologically inflationary appeals to abstract objects of various kinds, or to “block” theories of time. The paper closes with the articulation of an ontologically parsimonious solution to the metaphysical challenge to historiography. The cost of this approach is a revision to standard theories of truth. The central claim here is that the standard theories of truth have mistaken distinct causes of truth for truth itself. This mistake leads to distorted expectations regarding truth-makers for historiographical claims. The truth-makers of historiographical claims are not so much the historical events themselves but atemporal modal facts about the order of things of which those events were a part. (shrink)

Paul Thagard’s theory of deductive coherence, as set out in his Coherence in Thought and Action, faces a regress objection. Thagard’s method of solving deductive coherence problems presupposes some notion of logical consequence. The problem of specifying which logic to use to this end is itself a deductive coherence problem, so we would expect Thagard’s theory to be able to solve it. However, on pain of regress, the theory of deductive coherence cannot reach such a solution.

The study of truth is often seen as running on two separate paths: the nature path and the logic path. The former concerns metaphysical questions about the ‘nature’, if any, of truth. The latter concerns itself largely with logic, particularly logical issues arising from the truth-theoretic paradoxes. Where, if at all, do these two paths meet? It may seem, and it is all too often assumed, that they do not meet, or at best touch in only incidental ways. It is (...) often assumed that work on the metaphysics of truth need not pay much attention to issues of paradox and logic; and it is likewise assumed that work on paradox is independent of the larger issues of metaphysics. Philosophical work on truth often includes a footnote anticipating some resolution of the paradox, but otherwise tends to take no note of it. Likewise, logical work on truth tends to have little to say about metaphysical presuppositions, and simply articulates formal theories, whose strength may be measured, and whose properties may be discussed. In practice, the paths go their own ways. Our aim in this paper is somewhat modest. We seek to illustrate one point of intersection between the paths. Even so, our aim is not completely modest, as the point of intersection is a notable one that often goes unnoticed. We argue that the ‘nature’ path impacts the logic path in a fairly direct way. What one can and must say about the logic of truth is influenced, or even in some cases determined, by what one says about the metaphysical nature of truth. In particular, when it comes to saying what the well-known Liar paradox teaches us about truth, background conceptions — views on ‘nature’ — play a significant role in constraining what can be said. This paper, in rough outline, first sets out some representative ‘nature’ views, followed by the ‘logic’ issues (viz., paradox), and turns to responses to the Liar paradox. What we hope to illustrate is the fairly direct way in which the background ‘nature’ views constrain — if not dictate — responses to the main problem on the ‘logic’ path.. (shrink)

According to a widespread interpretation, in the Investigations Wittgenstein adopted a deflationary or redundancy theory of truth. On this view, Wittgenstein’s pronouncements about truth should be understood in the light of his invocation of the equivalences ‘p’ is true = p and ‘p’ is false = not p. This paper shows that this interpretation does not do justice to Wittgenstein’s thoughts. I will be claiming that, in fact, in his second book Wittgenstein is returning to the pre-Tractarian notion of bipolarity, (...) and that his new development of this notion in the Investigations excludes the redundancy-deflationary reading. Wittgenstein’s thoughts about truth are instead compatible with another interpretative option: Wittgenstein remains faithful to his methodological pronouncements, and he merely presents us with platitudes about the notions of “true” and “false”. (shrink)

In this paper, I outline and defend a novel approach to alethic pluralism, the thesis that truth has more than one metaphysical nature: where truth is, in part, explained by reference, it is relational in character and can be regarded as consisting in correspondence; but where instead truth does not depend upon reference it is not relational and involves only coherence. In the process, I articulate a clear sense in which truth may or may not depend upon reference: this involves (...) distinguishing semantic denotation from pragmatic speaker reference and claiming that there may or may not exist a metasemantic connection between these two notions. Finally, I argue that reference is not in general inscrutable—that this metasemantic connection does exist in the case of our ordinary discourse about present macroscopic concrete objects—but that it is in pure mathematics, where reference cannot be secured, and which therefore plays no role in accounting for truth. In this manner, alethic pluralism is upheld. (shrink)