I argue that satisfaction and reference—and therefore, truth—are multiply realizable properties. I advocate a novel approach motivated by a commitment to the robustness and fruitfulness of truth-theoretic approaches to natural language semantics. DEFLATIONISM: Philosophers keen on deflating the metaphysical pretensions of truth theories claim that we need not appeal to a substantive truth-property. Recently, however, some philosophers have sought to combine deflationism about truth with the view that our concept of truth or the truth-predicate can play an important role in natural language semantics. TRUTH-THEORETIC SEMANTICS: The goal of a formal semantic theory of a natural language is to provide both the semantic values of that language’s lexically primitive items as well as the semantically significant modes of combining those basic elements into meaningful and more complex expressions. Most approaches have in common a commitment to finite stateability and compositionality as well as a commitment to something like Davidson’s “Convention T.” PLURALISM: Pluralists about truth argue that different areas of discourse have different truth-properties. Can pluralism successfully be combined with a commitment to truth-theoretic semantics? OPEN SEMANTIC FUNCTIONALISM: The pluralist approaches to truth are unsatisfactory for a variety of reasons. The only option, I argue, is to regard truth as multiply-realizable. Specifically, we should view the set of truth’s realizers as possessing non-actual members—as being “open.” Truth is defined in the usual way in terms of reference and satisfaction, but these latter two relations are to be understood as multiply realizable but open. The property of truth can be specified using the Ramsey/Lewis method. My final view—Open Semantic Functionalism—respects compositionality and finite stateability, avoids triviality, handles plurality, and fits with robust, explanatorily significant natural language semantic theories.

Philosophical enquiry on the notion of truth has traditionally involved the identification of a class of objects to which truth is ascribed. At the same time, formal investigations are often required when the notion of truth is at issue: semantic paradoxes force in fact philosophers to shape their arguments in a precise way. Objects of truth, in formal context, are always reduced to other, more manageable objects that mimic their structural properties such as numbers or sets. This form of reduction renders the distinction between linguistic or syntactic objects, to which truth is usually applied, and their mathematical counterparts opaque, at least from the point of view of the theory of truth. In informal metatheoretic discussion, in fact, they are clearly different entities. In this thesis we focus on an alternative way of constructing axiomatic theories of truth in which syntactic objects and mathematical objects belong to different universes. A brief introduction tries to situate the proposed theories in the context of different investigations on axiomatic truth. Chapter 2 is devoted to the discussion of historical and more theoretical motivations behind the proposed alternative. Chapter 3 will present the syntactic koinè spoken by our theories. Morphological categories of the object language and logical concepts concerning the object theory will be formalised in a recent axiomatisation of hereditarily finite sets. In Chapter 4 we finally introduce theories of truth with a built-in syntactic theory and examine some of their consequences. We briefly focus on disquotational truth, then consider compositional axioms for truth. Chapter 5 investigates a possible application of the setting just introduced: a realisation of the all-present interaction, in metamathematical practice, between informal metatheoretic claims and their (suitably chosen) coded counterparts. In the final chapter, after a brief characterisation of the key doctrines of the delflationary conception of truth, we evaluate the impact that the theories of truth studied in this work can have on the debate on the so-called conservativeness argument, which tries to match the alleged insubstantiality of the notion of truth, advocated by deflationists, with the deductive power of deflationary acceptable theories of truth.

Doctor of Philosophy / Many criticisms of the prevalent deflationary theories of truth stem from some misunderstanding. Clarification can be found from considering Quine's reasoning on the disquotational feature of the truth predicate. Quine's disquotationalism and Horwich's minimalism are similar theses with respect to the concept of truth, though the difference between the choices of the primary truth bearers and the divergence in their accounts of meaning and reference are striking. Chapter Two is devoted to making plain Quine's reasoning regarding the disquotational concept of truth, and to constructing a disquotational theory of truth. Also in this chapter, the topic of how to enhance the deductive power of this theory is discussed. The following chapter aims to square Quine's theses of inscrutability of reference and ontological relativity, with an account of the disquotational schema of reference. Whether or not a disquotational schema of reference and all its instances can be seen as providing a genuine reference scheme, as claimed by Horwich and most deflationists, is also discussed. In Chapter Four, after an introduction of Horwich's minimalist conception of truth, there are a number of issues considered, in particular Horwich’s use-theoretic account of meaning and compositionality, along with the divergence between his account of meaning and Quine's. The final chapter, Chapter Five, provides a thorough analysis of three important factors regarding the disquotational theory and the minimal theory of truth. Among them, the first factor discussed is what sort of equivalence relation occurs within each instance of the disquotational schema or each axiom of the equivalence schema. Following this, there is an analysis of in what way the disquotationalist and the minimalist can explain all general facts involving truth. The last factor involves considering the proper ascription of the disquotational or the minimal truth predicate. Along with the analysis of these three factors, the issue regarding which theory of truth is preferable is elaborated.

Doctor of Philosophy / Many criticisms of the prevalent deflationary theories of truth stem from some misunderstanding. Clarification can be found from considering Quine's reasoning on the disquotational feature of the truth predicate. Quine's disquotationalism and Horwich's minimalism are similar theses with respect to the concept of truth, though the difference between the choices of the primary truth bearers and the divergence in their accounts of meaning and reference are striking. Chapter Two is devoted to making plain Quine's reasoning regarding the disquotational concept of truth, and to constructing a disquotational theory of truth. Also in this chapter, the topic of how to enhance the deductive power of this theory is discussed. The following chapter aims to square Quine's theses of inscrutability of reference and ontological relativity, with an account of the disquotational schema of reference. Whether or not a disquotational schema of reference and all its instances can be seen as providing a genuine reference scheme, as claimed by Horwich and most deflationists, is also discussed. In Chapter Four, after an introduction of Horwich's minimalist conception of truth, there are a number of issues considered, in particular Horwich’s use-theoretic account of meaning and compositionality, along with the divergence between his account of meaning and Quine's. The final chapter, Chapter Five, provides a thorough analysis of three important factors regarding the disquotational theory and the minimal theory of truth. Among them, the first factor discussed is what sort of equivalence relation occurs within each instance of the disquotational schema or each axiom of the equivalence schema. Following this, there is an analysis of in what way the disquotationalist and the minimalist can explain all general facts involving truth. The last factor involves considering the proper ascription of the disquotational or the minimal truth predicate. Along with the analysis of these three factors, the issue regarding which theory of truth is preferable is elaborated.

Truth: A Traditional Debate Reviewed”. This paper proposes a critical review of the presuppositions at the background of the traditional discussion on truth. Despite acknowledging that the said discussion rationalizes many of the movements and tentatives of its main characters to clarify the facts, it isascertained that, since it is centered in a reductive analyses of truth, it is not apt to generate the most adequate interpretation of the same. The theories in dispute will be expounded and criticized: deflationism, intrinsicalism, and both forms of relationism –coherentism and correspondence. An alternative to theanalytical-theoretical approach to truth –which in its different guises has served as basis of the traditional debate– will be purported. / El artículo plantea una revisión crítica de los presupuestos sobrelos cuales se funda el debate tradicional acerca de la verdad. A pesar de reconocerse que dicho debate racionaliza muchos de los movimientos e intentos de clarificación hechos por sus protagonistas, se afirma que, en la medida en que está centrado en un análisis reductivo del concepto en cuestión, no es elindicado para generar la interpretación más adecuada del mismo. A lo largo del trabajo, se expondrán y criticarán las teorías que han entrado en disputa en este terreno: el deflacionismo, el intrinsecalismo y las dos formas de relacionismo, el coherentismo y la correspondencia. Hacia el final se llega a sostener una aproximación a la verdad que se erige como alternativa frente ala analítico-teorética, la cual, en sus muchas y diversas formas, ha constituido la base del debate tradicional.

Im Rahmen dieser Arbeit werden zwei allgemeine Ziele verfolgt: ein negatives und ein positives. Das negative Ziel besteht darin, den Nachweis zu liefern, daß auf der Grundlage einer deflationistischen Konzeption der Wahrheit keine angemessene philosophische Analyse der Wahrheit gegeben werden kann. Meine kritische Aufmerksamkeit galt dabei vor allem den Varianten dieser Art von Wahrheitskonzeption, die gegenwärtig auch tatsächlich (noch) vertreten werden. Das positive Ziel besteht darin, eine plausible und alternative Konzeption der Wahrheit zu entwickeln, die manche richtigen Beobachtungen deflationistischer Konzeptionen der Wahrheit in sich aufnimmt, aber vor allem die Fehler und Schwächen dieser Konzeptionen vermeidet und ausräumt.

Im Rahmen dieser Arbeit werden zwei allgemeine Ziele verfolgt: ein negatives und ein positives. Das negative Ziel besteht darin, den Nachweis zu liefern, daß auf der Grundlage einer deflationistischen Konzeption der Wahrheit keine angemessene philosophische Analyse der Wahrheit gegeben werden kann. Meine kritische Aufmerksamkeit galt dabei vor allem den Varianten dieser Art von Wahrheitskonzeption, die gegenwärtig auch tatsächlich (noch) vertreten werden. Das positive Ziel besteht darin, eine plausible und alternative Konzeption der Wahrheit zu entwickeln, die manche richtigen Beobachtungen deflationistischer Konzeptionen der Wahrheit in sich aufnimmt, aber vor allem die Fehler und Schwächen dieser Konzeptionen vermeidet und ausräumt.

I here develop a specific version of the deflationary theory of truth. I adopt a terminology on which deflationism holds that an exhaustive account of truth is given by the equivalence between truth-ascriptions and de-nominalised (or disquoted) sentences. An adequate truth-theory, it is argued, must be finite, non-circular, and give a unified account of all occurrences of “true”. I also argue that it must descriptively capture the ordinary meaning of “true”, which is plausibly taken to be unambiguous. Ch. 2 is a critical historical survey of deflationary theories, where notably disquotationalism is found untenable as a descriptive theory of “true”. In Ch. 3, I aim to show that deflationism cannot be finitely and non-circularly formulated by using “true”, and so must only mention it. Hence, it must be a theory specifically about the word “true” (and its foreign counterparts). To capture the ordinary notion, the theory must thus be an empirical, use-theoretic, semantic account of “true”. The task of explaining facts about truth now becomes that of showing that various sentences containing “true” are (unconditionally) assertible. In Ch. 4, I defend the claim (D) that every sentence of the form “That p is true” and the corresponding “p” are intersubstitutable (in a use-theoretic sense), and show how this claim provides a unified and simple account of a wide variety of occurrences of “true”. Disquotationalism then only has the advantage of avoiding propositions. But in Ch. 5, I note that (D) is not committed to propositions. Use-theoretic semantics is then argued to serve nominalism better than truth-theoretic ditto. In particular, it can avoid propositions while sustaining a natural syntactic treatment of “that”-clauses as singular terms and of “Everything he says is true”, as any other quantification. Finally, Horwich’s problem of deriving universal truth-claims is given a solution by recourse to an assertibilist semantics of the universal quantifier.

À quelles conditions deux objets singuliers sont-ils identiques, ou distincts au contraire ? Cette thèse choisit de ne pas aborder cette question de front, en proposant immédiatement des critères – des conditions nécessaires et suffisantes – d’identité pour certains types d’objets (les personnes, les artefacts, les objets inanimés…). Elle commence bien plutôt par prendre du recul, en demandant ce que sont de tels objets ordinaires, quelle est leur ontologie, et quelle est par conséquent la nature d’une relation d’identité entre eux. La conclusion de cette enquête, menée dans une perspective néo-carnapienne, est déflationniste : les relations d’identité numérique entre objets ordinaires ne sont pas déjà présentes dans le monde, comme des faits substantiels que nous n’aurions plus qu’à découvrir. Après avoir élaboré cette théorie de l’identité dans une première partie, cette thèse la met ensuite au travail, pour résoudre dans une deuxième partie les principaux paradoxes de l’identité dont la littérature regorge : problèmes liés au vague, aux modalités, à la coïncidence, problèmes enfin d’identité personnelle. / Under what conditions are two singular objects identical or distinct? This thesis chooses not to tackle this question upfront, by directly putting forward criteria – that is, necessary and sufficient conditions – of identity for certain kinds of objects (such as persons, artefacts, inanimate objects…). It rather begins by stepping backwards, in order to tell a story about ordinary objects, about their ontology, and consequently about the nature of the relation of numerical identity between two such objects. The upshot of this enquiry, led under the guidance of a neo-Carnapian meta-philosophy, is deflationary: numerical identity relations between ordinary objects are not already there in the world, like substantial facts waiting to be discovered. After elaborating such a theory of identity in the first part, this thesis then uses it to solve most of the well-known problems of identity, in the second part: those related to vagueness, essentialism and modality, spatio-temporal coincidence, and eventually personal identity.