The Liar Paradox and related semantic antinomies seem to challenge our deepest intuitions about language, truth and logic. Many philosophers believe that to solve them, we must give up either classical logic, or the expressive resources of natural language, or even the “naïve theory of truth” (according to which "P" and “it is true that 'P'” always entail each other). A particularly extreme form of radical surgery is proposed by figures like Graham Priest, who argues for “dialetheism”—the position that some contradictions are actually true—on the basis of the paradoxes. While Priest’s willingness to dispense with the Law of Non-Contradiction may be unpopular in contemporary analytic philosophy, figures as significant as Saul Kripke and Hartry Field have argued that, in light of the paradoxes, we can only save Non-Contradiction at the expense of the Law of the Excluded Middle, abandoning classical logic in favor of a “paracomplete” alternative in which P and ~P can simultaneously fail to hold. I believe that we can do better than that, and I argue for a more conservative approach, which retains not only “monaletheism” (the orthodox position that no sentence, either in natural languages or other language, can have more than one truth-value at a time), but the full inferential resources of classical logic.

Thesis (Ph.D.)--University of Edinburgh, 1996.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2016-09-01T14:35:27Z No. of bitstreams: 1 Francisco Valdério Pereira da Silva Júnior.pdf: 1912890 bytes, checksum: 4665cb8564dd1128925fc821bc306a26 (MD5) / Made available in DSpace on 2016-09-01T14:35:27Z (GMT). No. of bitstreams: 1 Francisco Valdério Pereira da Silva Júnior.pdf: 1912890 bytes, checksum: 4665cb8564dd1128925fc821bc306a26 (MD5) Previous issue date: 2016-02-24 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão / This thesis addresses the relationship between Eric Weil and Paul Ricoeur. Despite being their styles fully different, at the treatment of philosophical questions, their perspectives converge in what we advocate here under the statute's project of philosophy - whether for a Logic of Philosophy (Weil), whether in a philosophical hermeneutics (Ricoeur). Weil and Ricoeur opt for this sense in any discourse, even in attempts to eliminate the sense, by attestation of indecision in view of the conflict of interpretations and / or of the impossibility of reducing violence to the speech. Neither the philosophy's logician, nor the hermeneut, it makes any concession to the easy reading of the multiplicity of discourses, trying to suppress them at a totalizing mediation. Nor they give in in to the powerful devastating criticism of the possibility of universalization that by supporting the radical polarization between every speech, consolidates fragmentation and permanent insuperability the deadlock environment. The resource that both throw hand is the resumption: concept able to operate a guidance through the discursive disparities in confrontation, respecting them the difference, while that rises beyond all fragmentation and incommunicability. Accepting the challenge of thinking about continuity, in spite of the ruptures in the history and discourse, they seek lead to reflection at the level of universal understanding by the possibility of coherent directioning, that is, judicious. In this sense, the thesis argues that the taking of Ricoeur's position is not only in favor of the weiliano philosophical project – synthesized in the Kantian formula post-Hegelian –, It is also the effective reappropriation of this active project, now, no longer by the chain of discursive typologies, but through the philosophical singularities / Essa tese aborda a relação entre Éric Weil e Paul Ricoeur. Malgrado estilos inteiramente distintos no tratamento das questões filosóficas, suas perspectivas convergem para o que aqui advogamos sob o estatuto do projeto da filosofia – seja por uma Lógica da Filosofia (Weil), seja numa hermenêutica filosófica (Ricoeur). Weil e Ricoeur optam pelo sentido presente em todo discurso, mesmo no que procura eliminar o sentido pela atestação da indecisão diante do conflito das interpretações e/ou da impossibilidade da redução da violência ao discurso. Nem o lógico da filosofia nem o hermeneuta fazem qualquer concessão à fácil leitura da multiplicidade dos discursos tentando suprimi-los numa mediação totalizadora. Tampouco cedem para a poderosa crítica demolidora da possibilidade de universalização que, ao sustentar a polarização radical entre todos os discursos, consolida a fragmentação e o permanente ambiente de insuperabilidade do impasse. O recurso que ambos lançam mão é a retomada: conceito capaz de operar uma orientação através das disparidades discursivas em confronto, respeitando-lhes a diferença, ao mesmo tempo em que as eleva além de toda fragmentação e incomunicabilidade. Aceitando o desafio de pensar a continuidade a despeito das rupturas, na história e no discurso, buscam conduzir a reflexão ao nível da compreensão universal pela possibilidade do direcionamento coerente, isto é, sensato. Nesse sentido, a tese defende que a tomada de posição de Ricoeur não é apenas em favor do projeto filosófico weiliano – sintetizado na fórmula kantiano pós-hegeliano –, é também a reapropriação efetiva desse projeto atuante, agora, não mais pelo encadeamento das tipologias discursivas, mas através das singularidades filosóficas

Zugl.: Bielefeld, Universiẗat, Diss., 2003.

La présente thèse de doctorat propose une interprétation du Tractatus logico-philosophicus qui prend pour fil directeur l'analyse de la distinction opérée par Ludwig Wittgenstein entre « ce qui peut être dit » et « ce qui se montre ». Il s'agit, à partir d'une étude de la relation entre les développements logiques du Traité et son aspect « mystique » (c'est-à-dire ses considérations concernant la notion de valeur absolue), de poser le problème de son unité structurelle. L'unité du premier ouvrage de Wittgenstein s'avère étroitement liée à la distinction entre dire et montrer en laquelle résident selon l'auteur l'« argument principal » de son livre et le « problème cardinal de la philosophie ». Afin d'expliquer l'unité du Tractatus, ce travail de recherche s'efforce d'élucider la nature de la distinction dire/montrer, d'abord par une analyse de ses applications dans les remarques dont le Traité est composé, puis par une enquête sur ses origines dans les œuvres de Gottlob Frege, Bertrand Russell, Arthur Schopenhauer, Otto Weininger, William James et Léon Tolstoï. Selon la lecture du texte ici présentée, tous les emplois de cette distinction participent d'une forme commune qui est liée à la notion de réflexivité (ou d'autoréférence). / This PhD thesis deals with Wittgenstein's Tractatus Logico-philosophicus and intends to construct an interpretation of the book by using the distinction between ‘what can be said' and ‘what shows itself' as a central thread. Starting from a study of the relationship between the logical developments of the treatise and its ‘mystical' aspect (i.e. its remarks on the idea of an absolute value), the thesis raises the problem of the structural unity of Wittgenstein's early work. It appears that this unity is intimately related to the distinction between saying and showing, which is, according to Wittgenstein, the ‘main point' of his book and ‘the cardinal problem of philosophy'. To explain the unity of the Tractatus, the present work tries to elucidate the nature of the say/show distinction—first, through an analysis of its use in the book, and second, through an investigation into its origins in the works of Frege, Russell, Hertz, Schopenhauer, Weininger, James, and Tolstoy. According to the reading presented here, all the uses of this distinction pertain to a common form, which is linked to the concept of reflexiveness (or self-reference).

Made available in DSpace on 2014-12-17T15:12:07Z (GMT). No. of bitstreams: 1 MariaJoseCSV .pdf: 1869360 bytes, checksum: 04bf85774d6a72cfbffe74b544a35684 (MD5) Previous issue date: 2007-10-31 / The philosophical discussion has been present throughout the whole history of reason, for philosophy and reason have been always closely linked. In the following work, Reason, origin, crises and contemporary answers I go into the history of the rational and demonstrative thought, focusing on how rationality can be thought about in contemporary philosophy. To answer this question I discuss the principle of philosophy, the mythical period and the thoughts of Heraclito , Parmenides , Plato and Aristotle in relation to reason and rationality. Also discussed is the medieval period and the philosophical use of logic and the criticism of Aristotle s thoughts, especially focusing on the criticism of Hegel and Luckasiewicz of the non contradiction principle. Lastly I discuss the development of reason in present day philosophy, mainly how modern logics could be putting at stake Aristotle s model of reason / A discuss?o que permeia a hist?ria da raz?o ? o debate filos?fico por excel?ncia, uma vez que raz?o e filosofia andam juntas. Assim, em Raz?o - origem, crise e respostas contempor?neas, o objetivo desta pesquisa se d? a partir de olhares na hist?ria do desenvolvimento do pensamento racional e demonstrativo. Com esses olhares problematizaremos como se pode pensar na filosofia contempor?nea a racionalidade. Quais os princ?pios de racionalidade norteiam a nossa no??o atual de raz?o? Para buscar respostas retornaremos ao princ?pio da filosofia, passaremos pela fase dos mitos, analisaremos as contribui??es de Her?clito e Parm?nides as primeiras concep??es de raz?o e veremos os desdobramentos destas com Plat?o e Arist?teles. Este ?ltimo sendo o personagem desse desenvolvimento da racionalidade antiga. A partir da? entram em cena os medievais e o uso filos?fico da l?gica, por conseguinte discutiremos as vozes questionadoras ao pensamento aristot?lico, Hegel e sua cr?tica ao princ?pio de n?o-contradi??o, assim como as indaga??es e cr?ticas de Lukasiewicz. Nessa perspectiva veremos o est?gio atual do desenvolvimento da raz?o, com as l?gicas modernas que se contrap?em ao modelo de raz?o pautado por Arist?teles e desse modo consideraremos como pensar a racionalidade nos dias atuais

Frege wanted to show that arithmetical truths are logical by proving them from purely logical basic laws. But how do we know that these basic laws are logical? Frege uses generality and undeniability to make a prima facie case for logicality—if a truth is general and undeniable, then it's likely logical. I argue that Frege could, did, and had to make a deeper case for why we're right in recognizing his basic laws as logical. Implicit in his work is a view of logical laws as epistemically analytic—his arguments for his basic laws serve to elicit a reflective awareness of the fact that understanding them is sufficient for recognizing them to be true. This view both fits with Frege's comments concerning the connection between logic, truth, and normativity, and serves to explain why and in what sense he took logic to be general and conceptually undeniable. In my view, semantics must play a distinctive role in any rational reconstruction of Frege's case for logicality—the aforementioned “reflective awareness” must be an explicit appreciation of how the truth of formulas expressing Frege's laws follows quickly from his stipulations governing terms which figure in those formulas. Opposing this view is the elucidatory interpretation of Thomas Ricketts, Warren Goldfarb, and Joan Weiner, which holds that Frege's arguments for his basic laws can't be taken at face value, and must serve the merely elucidatory purpose of easing us into the language. Another reading is the correctness interpretation of Richard Heck and Jason Stanley, which holds that Frege's primary purpose in his arguments is justifying the claim that Frege's axioms, qua formulas, are true. I argue against both of these interpretations, and in doing so clarify the role and limits of semantics in Frege's enterprise.

The fusion Ll ? Lr of two normal modal logics formulated in languages with disjoint sets of modal operators is the smallest normal modal logic containing Ll [ Lr. This paper proves that decidability, interpolation, uniform interpolation, and Halld?encompleteness are preserved under forming fusions of normal polyadic polymodal logics. Those problems remained open in [Fine & Schurz [3]] and [Kracht & Wolter [10]]. The paper defines the fusion `l ? `r of two classical modal consequence relations and proves that decidability transfers also in this case. Finally, these results are used to prove a general decidability result for modal logics based on superintuitionistic logics.

In broadest terms, this thesis is concerned to answer the question of whether the view that arithmetic is analytic can be maintained consistently. Lest there be much suspense, I will conclude that it can. Those who disagree claim that accounts which defend the analyticity of arithmetic are either unable to give a satisfactory account of the foundations of mathematics due to the incompleteness theorems, or, if steps are taken to mitigate incompleteness, then the view loses the ability to account for the applicability of mathematics in the sciences. I will show that this criticism is not successful against every view whereby arithmetic is analytic by showing that the brand of "conventionalism" about mathematics that Rudolf Carnap advocated in the 1930s, especially in Logical Syntax of Language, does not suffer from these difficulties. There, Carnap develops an account of logic and mathematics that ensures the analyticity of both. It is based on his famous "Principle of Tolerance", and so the major focus of this thesis will to defend this principle from certain criticisms that have arisen in the 80 years since the book was published. I claim that these criticisms all share certain misunderstandings of the principle, and, because my diagnosis of the critiques is that they misunderstand Carnap, the defense I will give is of a primarily historical and exegetical nature. Again speaking broadly, the defense will be split into two parts: one primarily historical and the other argumentative. The historical section concerns the development of Carnap's views on logic and mathematics, from their beginnings in Frege's lectures up through the publication of Logical Syntax. Though this material is well-trod ground, it is necessary background for the second part. In part two we shift gears, and leave aside the historical development of Carnap's views to examine a certain family of critiques of it. We focus on the version due to Kurt Gödel, but also explore four others found in the literature. In the final chapter, I develop a reading of Carnap's Principle - the `wide' reading. It is one whereby there are no antecedent constraints on the construction of linguistic frameworks. I argue that this reading of the principle resolves the purported problems. Though this thesis is not a vindication of Carnap's view of logic and mathematics tout court, it does show that the view has more plausibility than is commonly thought.

In this thesis I discuss the problems associated with the epistemological task of arriving at basic logical knowledge. This is knowledge that the primitive rules of inference we use in deductive reasoning are correct. Knowledge of correctness, like all knowledge, is available to us either as the product of inference, or it is available non-inferentially. Success in the campaign to justify the correctness of these rules is mired by opposing views on how to do this properly. Inferential justifications of rules of inference, which are based on reasons, lead to regressive or circular results. Non-inferential justifications, based on something other than reasons, at first do not seem to fare any better: without a basis for these justifications, they appear arbitrary and unfounded. The works of Boghossian and Dummett who argue for an inferentialist approach, and Hale who supports non-inferentialism are carefully examined in this thesis. I conclude by finding superiority in Hale's suggestion that a particular set of basic logical constants are indispensable to deductive reasoning. I suggest that we endorse a principle which states that rules are not premises, and are therefore to be excluded from expression as statements in a deductive argument. I argue that the quality of being indispensable is sufficient for a basic rule of deduction to be countenanced as default-justified, and therefore need not be expressed in argument. By a rule's evading expression in argument, it avoids circular reasoning in deductive arguments about its own correctness. Another important outcome that emerges from my research is the finding that non-inferential knowledge is ontologically prior to the inferential sort. This is because plausible inferential knowledge of basic logical constants shall always be justified by circular reasoning that already assumes the correctness of the rule to be vindicated. This initial assumption is tantamount to non-inferential knowledge, and therefore this latter is more primitive-in fact the only primitive-species of basic logical knowledge.