Towards a Neuroscientific Theory of Reference

The topic of the dissertation is reference of proper names. It criticizes the amalgam of the current standard theory, direct-causal theory of reference, and defends Fregean sense theory of reference. In addition Fregean view is neuronaturalized by Gerald Edelman's idea of recurrent networks, combined with temporal synchrony of neural processing which is generalized to explain conceptual information. Direct-causal theory's main arguments - modal, epistemological and semantic - are all shown to be too weak and based on mistaken presuppositions like synonymy between proper names and descriptions. Causal communicative links are shown to be weak for reference retention also. Intentions to retain the original referent are too weal as well. Moreover the "intuitive arguments" invoked by the direct-causal theorists are misguided and shown to be based on basic schema of reference, a postulation proposed to explain precondition of referential language use. Reference is grounded on information transmission and its embodiment in neurocognitive processes mainly having to do with neural memory systems. So contrary to the direct-causal theorists' view reference is cognitive through and through as Fregean theory maintains. Classical problems in philosophy of language, like informationality of identity statements, propositional attitude contexts, among others, are solved.Väitöksen aihe erisnimien viittaus. Siinä kritisoidaan vallitsevaa teoria-amalgaamia, suora kausaalinen viittauksen teoria. Työssä puolustetaan fregeläistä viittauksen merkitysteoriaa, joka tieteellistetään neuronaturalisoimalla se. Tässä käytetään takaisinpäin vaikuttavia neuronisysteemeitä sekä neuraali-impulssien prosessointisyknroniaa. Suoran kausaalisen teorian keskeiset argumentit osoitetaan riittämättömiksi samoin kuin kausaaliset viittausmekanismit sekä viittausintentiot. Lisäksi kyseisen teorian "intuitiiviset argumentit" osoitetaan perustuvan väärinymmärrykseen ja selitetään työssä postuloituun viittauksen perusskeemaan perustuviksi. Tämä skeema selittää kielellisten ilmausten viittauksen edellytyksen. Viittaus on informaation välitykseen ja neurokognitiivisiin prosesseihin perustuvaa, fregeläisen teorian mukaisesti. Työ antaa tälle näkemykselle neurotieteellisen viitekehyksen

An Objection to Naturalism and Atheism from Logic

I proffer a success argument for classical logical consequence. I articulate in what sense that notion of consequence should be regarded as the privileged notion for metaphysical inquiry aimed at uncovering the fundamental nature of the world. Classical logic breeds necessitism. I use necessitism to produce problems for both ontological naturalism and atheism

Seeing, Knowing, doing : case studies in modal logic

Dans le domaine des jeux vidéos par exemple, surtout des jeux de rôles, les personnages virtuels perçoivent un environnement, en tirent des connaissances puis effectuent des actions selon leur besoin. De même en robotique, un robot perçoit son environnement à l'aide de capteurs/caméras, établit une base de connaissances et effectuent des mouvements etc. La description des comportements de ces agents virtuels et leurs raisonnements peut s'effectuer à l'aide d'un langage logique. Dans cette thèse, on se propose de modéliser les trois aspects "voir", "savoir" et "faire" et leurs interactions à l'aide de la logique modale. Dans une première partie, on modélise des agents dans un espace géométrique puis on définit une relation épistémique qui tient compte des positions et du regard des agents. Dans une seconde partie, on revisite la logique des actions "STIT" (see-to-it-that ou "faire en sorte que") qui permet de faire la différence entre les principes "de re" et "de dicto", contrairement à d'autres logiques modales des actions. Dans une troisième partie, on s'intéresse à modéliser quelques aspects de la théorie des jeux dans une variante de la logique "STIT" ainsi que des émotions contre-factuelles comme le regret. Tout au long de cette thèse, on s'efforcera de s'intéresser aux aspects logiques comme les complétudes des axiomatisations et la complexité du problème de satisfiabilité d'une formule logique. L'intégration des trois concepts "voir", "savoir" et "faire" dans une et une seule logique est évoquée en conclusion et reste une question ouverte.Agents are entities who perceive their environment and who perform actions. For instance in role playing video games, ennemies are agents who perceive some part of the virtual world and who can attack or launch a sortilege. Another example may concern robot assistance for disabled people: the robot perceives obstacles of the world and can alert humans or help them. Here, we try to give formal tools to model knowledge reasoning about the perception of their environment and about actions based, on modal logic. First, we give combine the standard epistemic modal logic with perception constructions of the form (agent a sees agent b). We give a semantics in terms of position and orientation of the agents in the space that can be a line (Lineland) or a plane (Flatland). Concerning Lineland, we provide a complete axiomatization and an optimal procedure for model-checking and satisfiability problem. Concerning Flatland, we show that both model-checking and satisfiability problem are decidable but the exact complexities and the axiomatization remain open problems. Thus, the logics of Lineland and Flatland are completely a new approach: their syntax is epistemic but their semantics concern spatial reasoning. Secondly, we study on the logic of agency ``see-to-it-that'' STIT made up of construction of the form [J]A standing for ``the coalition of agents J sees to it that A''. Our interest is motivated: STIT is strictly more expressive that standard modal logic for agency like Coalition Logic CL or Alternating-time Temporal Logic ATL. In CL or ATL the ``de re'' and ``de dicto'' problem is quite difficult and technical whereas if we combine STIT-operators with epistemic operators, we can solve it in a natural way. However this strong expressivity has a prize: the general version of STIT is undecidable. That is why we focus on some syntactic fragments of STIT: either we restrict the allowed coalitions J in constructions [J]A or we restrict the nesting of modal STIT-operators. We provide axiomatizations and complexity results. Finally, we give flavour to epistemic modal logic by adding STIT-operators. The logic STIT is suitable to express counterfactual statements like ``agent a could have choosen an action such that A have been true''. Thus we show how to model counterfactual emotions like regret, rejoicing, disappointment and elation in this framework. We also model epistemic games by adapting the logic STIT by giving explicitely names of actions in the language. In this framework, we can model the notion of rational agents but other kind of behaviour like altruism etc., Nash equilibrium and iterated deletion of strictly dominated strategies

The History and Prehistory of Natural-Language Semantics

Contemporary natural-language semantics began with the assumption that the meaning of a sentence could be modeled by a single truth condition, or by an entity with a truth-condition. But with the recent explosion of dynamic semantics and pragmatics and of work on non- truth-conditional dimensions of linguistic meaning, we are now in the midst of a shift away from a truth-condition-centric view and toward the idea that a sentence’s meaning must be spelled out in terms of its various roles in conversation. This communicative turn in semantics raises historical questions: Why was truth-conditional semantics dominant in the first place, and why were the phenomena now driving the communicative turn initially ignored or misunderstood by truth-conditional semanticists? I offer a historical answer to both questions. The history of natural-language semantics—springing from the work of Donald Davidson and Richard Montague—began with a methodological toolkit that Frege, Tarski, Carnap, and others had created to better understand artificial languages. For them, the study of linguistic meaning was subservient to other explanatory goals in logic, philosophy, and the foundations of mathematics, and this subservience was reflected in the fact that they idealized away from all aspects of meaning that get in the way of a one-to-one correspondence between sentences and truth-conditions. The truth-conditional beginnings of natural- language semantics are best explained by the fact that, upon turning their attention to the empirical study of natural language, Davidson and Montague adopted the methodological toolkit assembled by Frege, Tarski, and Carnap and, along with it, their idealization away from non-truth-conditional semantic phenomena. But this pivot in explana- tory priorities toward natural language itself rendered the adoption of the truth-conditional idealization inappropriate. Lifting the truth-conditional idealization has forced semanticists to upend the conception of linguistic meaning that was originally embodied in their methodology

The mathematicization of nature.

This thesis defends the Quine-Putnam indispensability argument for mathematical realism and introduces a new indispensability argument for a substantial conception of truth. Chapters 1 and 2 formulate the main components of the Quine-Putnam argument, namely that virtually all scientific laws quantify over mathematical entities and thus logically presuppose the existence thereof. Chapter 2 contains a detailed discussion of the logical structure of some scientific theories that incorporate or apply mathematics. Chapter 3 then reconstructs the central assumptions of Quine's argument, concluding (provocatively) that "science entails platonism". Chapter 4 contains a brief discussion of some major theories of truth, including deflationary views (redundancy, disquotation). Chapter 5 introduces a new argument against such deflationary views, based on certain logical properties of truth theories. Chapter 6 contains a further discussion of mathematical truth. In particular, non-standard conceptions of mathematical truth such as "if-thenism" and "hermeneuticism". Chapter 7 introduces the programmes of reconstrual and reconstruction proposed by recent nominalism. Chapters 8 discusses modal nominalism, concluding that modalism is implausible as an interpretation of mathematics (if taken seriously, it suffers from exactly those epistemological problems allegedly suffered by realism). Chapter 9 discusses Field's deflationism, whose central motivating idea is that mathematics is (pace Quine and Putnam) dispensable in applications. This turns on a conservativeness claim which, as Shapiro pointed out in 1983, must be incorrect (using Godel's Theorems). I conclude in Chapter 10 that nominalistic views of mathematics and deflationist views of truth are both inadequate to the overall explanatory needs of science

Stalnaker and Field on truth and intentionality.

In a series of publications, Robert Stalnaker and Hartry Field have undertaken a dispute about what is the correct way to explain intentionality naturalistically. Field wishes to assimilate mental intentionality to linguistic intentionality and to explain both kinds of intentionality using Tarskian truth theory plus the causal theory of reference. Stalnaker wishes to subsume mental intentionality under the notion of indication and to explain it on the model of measurement theory, leaving linguistic intentionality to be explained derivatively. I attempt to adjudicate their dispute, paying particular attention to the question whether Tarskian truth theory has a role to play in explaining intentionality naturalistically. The first half of the dissertation examines Tarski\u27s theory. I argue that Field and Stalnaker are incorrect when they agree that Tarski\u27s reduction of the notion of truth is defective and I explain Tarski\u27s \u27structural\u27 notion of truth. In the second half of the dissertation, I argue that Stalnaker\u27s criticisms of Field mostly do not stand up to scrutiny, but that Field\u27s theory is unsatisfactory nonetheless; I also argue that certain criticisms of Stalnaker do more damage than he thinks. I conclude that neither has solved \u27the problem of intentionality\u27, but that Stalnaker is right that truth theory as such will not have a role in the correct solution