What is mathematics about? And if it is about some sort of mathematical reality, how can we have access to it? This is the problem raised by Plato, which still today is the subject of lively philosophical disputes. This book traces the history of the problem, from its origins to its contemporary treatment. It discusses the answers given by Aristotle, Proclus and Kant, through Frege's and Russell's versions of logicism, Hilbert's formalism, Gödel's platonism, up to the the current debate on (...) Benacerraf's dilemma and the indispensability argument. Through the considerations of themes in the philosophy of language, ontology, and the philosophy of science, the book aims at offering an historically-informed introduction to the philosophy of mathematics, approached through the lenses of its most fundamental problem. (shrink)

In 1902 there arrived in Jena a letter from Russell laying out a proof that shattered Frege’s confidence in logicism, which is widely taken to be the doctrine according to which every truth of arithmetic is re-expressible without relevant loss as a provable truth about a purely logical object. Frege was persuaded that Russell had exposed a pathology in logicism, which faced him with the task of examining its symptoms, diagnosing its cause, assessing its seriousness, arriving at a treatment option, (...) and making an estimate of future prospects. The symptom was the contradiction that had crept into naïve set theory in the form of the set that provably is and is not its own member. The diagnosis was that it is caused by Basic Law V of the Grundgesetze (Frege, In: Grundgesetze der Arithmetik: Begrifsschriftlich abgeleitet, Jena: Herman Pohle, 1893/1903. Translated into English as Basic Laws of Arithmetic, also edited by Philip A. Ebert and Marcus Rossberg, with Crispin Wright, Oxford: Oxford University Press, 2013). Triage answers the question, “How bad is it?” The answer was that the contradiction irreparably destroys the logicist project. The treatment option was nil. The disease was untreatable. In due course, the prognosis turned out to be that a scaled-down Fregean logic could have an honourable life as a theory inference for various domains of mathematical discourse, but not for domains containing the logical objects required for logicism. Since there aren’t such objects, there aren’t such domains. On the face of it, Frege’s logicist collapse is astonishing. Why wouldn’t he have repaired the fault in Law V and gone back to the business of bringing logicism to an assured realization? In the course of our reflections, we will have nice occasion to consider the good it might have done Frege to have booked some time with Aristotle had he been able to. By the time we’re finished, we’ll have cause to think that in the end the Russell might well have begged the question against Frege. (shrink)

According to what Jonathan Bennett calls the Kant–Frege view of existence, Frege gave solid logical foundations to Kant’s claim that existence is not a real predicate. In this article I will challenge Bennett’s claim by arguing that although Kant and Frege agree on what existence is not, they agree neither on what it is nor on the importance and justification of existential propositions. I identify three main differences: first, whereas for Frege existence is a property of a concept, for Kant (...) it is a relational property pertaining between the concept and intuition of an object. Second, whereas for Frege truth about individuals presupposes their existence, for Kant truth is in many cases independent of the existence of objects. Third, whereas Frege binds logic to existence and removes modalities from logic, for Kant existence is a modal category that is emphatically removed from the domain of logic and set in the core of metaphysics. Due to these differences in Kant’s and Frege’s theories of existence, Frege cannot be seen as giving logical clarity to Kant’s view. (shrink)

In this paper, I aim to present the main components of my non-standard interpretation of Frege’s views on existence to the English-speaking public. First, I will outline the standard interpretation and show how to a great but not full extent the standard interpretation can be justified on the basis of Frege’s writings. Second, I show that the main error of the standard interpretation consists in the assimilation of the contents of the ordinary language expressions “exist” and “there is” according to (...) Frege. Third, I evaluate possible sources for this unfounded assimilation. After that, I outline my alternative interpretation that distinguishes in opposition to other non-standard interpretations between a substantive and a deflationary part of Frege’s complete conception of existence in analogy to Frege’s analysis of truth and negation. Fifthly, I justify my interpretation by the reconstruction of a so far overlooked master argument of Frege against the above-mentioned assimilation. In the last section, I introduce and discuss five objections against my interpretation that came to my attention. (shrink)

Assertion plays a crucial dual role in Frege's conception of logic, a formal and a transcendental one. A recurrent complaint is that Frege's inclusion of the judgement-stroke in the Begriffsschrift is either in tension with his anti-psychologism or wholly superfluous. Assertion, the objection goes, is at best of merely psychological significance. In this paper, I defend Frege against the objection by giving reasons for recognising the central logical significance of assertion in both its formal and its transcendental role.

Philosophers of the modern period are often presented as having made an elementary error: that of confounding the attitude one adopts toward a proposition with its content. By examining the works of Locke and the Port-Royalians, I show that this accusation is ill-founded and that Locke, in particular, has the resources to construct a theory of propositional attitudes.

The Frege-Russell view is that existence is a second-order property rather than a property of individuals. One of the most compelling arguments for this view is based on the premise that there is an especially close connection between existence and number. The most promising version of this argument is by C.J.F Williams (1981, 1992). In what follows, I argue that this argument fails. I then defend an account according to which both predications of number and existence attribute properties to individuals.

Illocutionary force and semantic content are widely held to occupy utterly different categories in at least two ways: Any expression serving as an indicator of illocutionary force must be without semantic content, and no such expression can embed. A refined account of the force/content distinction is offered here that does the explanatory work that the standard distinction does, while, in accounting for the behavior of a range of parenthetical expressions, shows neither nor to be compulsory. The refined account also motivates (...) a development of the "scorekeeping model" of conversation, helps to isolate a distinction between illocutionary force and illocutionary commitment, and reveals one precise respect in which meaning is only explicable in terms of use. (shrink)

Michael Dummett has argued that a formal semantics for our language is inadequate unless it can be shown to illuminate to our actual practice of speaking and understanding. This paper argues that Frege’s account of the semantics of predicate expressions according to which the reference of a predicate is a concept (a function from objects to truth values) has exactly the required characteristics. The first part of the paper develops a model for understanding the distinction between objects and concepts as (...) an ontological distinction. It argues that, ontologically, we can take a Fregean function to be generated by a property detection device that can register for any object the presence or absence of that property. This provides a direct connection between the semantics of sentences and the structure of perceptual judgment. The second part of the paper deals with arguments that have been mounted against the coherence of Frege’s semantics. It argues that some of these are question begging, while others are correct in so far as Frege’s claim is untenable if we assume that the syntactic categories singular term and predicate are primary, and the ontological categories are simply projections of these syntactic categories. However, the objections dissipate once we recognize that an independent ontological characterization of the distinction is available. (shrink)

O presente manual tem como intenção constituir um guia para uma disciplina introdutória de filosofia da linguagem. Foi elaborado a partir da leccionação da disciplina de Filosofia da Linguagem I na Faculdade de Letras da Universidade do Porto desde 2001. A disciplina de Filosofia da Linguagem I ocupa um semestre lectivo e proporciona aos estudantes o primeiro contacto sistemático com a área da filosofia da linguagem. Pretende-se que este manual ofereça aos estudantes os instrumentos necessários não apenas para acompanhar uma (...) iniciação ao campo da filosofia da linguagem mas também para o estudo e a investigação autónomos posteriores. Para isso é percorrido um trajecto que conduz das intuições pré-teóricas acerca de linguagem, de que todos dispomos, até um conhecimento disciplinar específico, histórico e temático, da filosofia da linguagem. Em termos práticos, são considerados como precedentes da disciplina de Filosofia da Linguagem I – mesmo se, pelo existem actualmente precedências em sentido estrito – as disciplinas de Lógica I e II e de Filosofia do Conhecimento I e II. Os programas dessas disciplinas nos últimos anos estiveram presentes por trás da elaboração do manual. (shrink)

Despite the often false impression that the analytic philosophy as an anti-metaphysical movement has nothing to do with metaphysics, there can be found good reasons to grant the metaphysical dispositions of analytic philosophers, and thereby, to minimize the anti-metaphysical nature of analytic philosophy in its all phases. Since analytic philosophy is a historical movement the main nature of which developed through several stages, the very kinds of metaphysical dispositions within each one of its various stages can be easily portrayed. In (...) the meantime, logical realism as the early stage of analytic philosophy contains plenty of metaphysical dispositions. Undoubtedly, one cannot say that analytic philosophy in this period was not committed to metaphysical theses about the plurality of entities, the ultimate nature of reality and the logical structure of the world. In this paper, then, after giving a relatively complete explanation of the logical realism, we claimed that although logical realists rejected the traditional speculative metaphysics of their predecessors, they also replaced it by the metaphysics of logic that pursues the metaphysical aims, this time, by logical means. So, we portrayed this kind of metaphysics as Bolzano’s Semantic Platonism, Frege’s and Russell’s Pluralistic Platonism, Russell’s Pluralistic Atomism, and Wittgenstein’s logical atomism. (shrink)

A crítica de Frege ao psicologismo evoluiu ao longo do tempo. O ponto principal desta evolução é a passagem da crítica do psicologismo em “Fundamentos da aritmética” àquela das “Leis básicas da aritmética”. O papel determinante nesta passagem se dá a partir da crítica que Frege recebeu de Kerry.

open journal of Philosophical Investigations (PI) is an international journal dedicated to the latest advancements in philosophy. The goal of this journal is to provide a platform for academicians all over the world to promote, share, and discuss various new issues and developments in different areas of philosophy. -/- All manuscripts to be prepared in English or Persian and are subject to a rigorous and fair peer-review process. Generally, accepted papers will appear online. The journal publishes papers including the following (...) fields: -/- · Analytic Philosophy · Ancient Greek and Roman Philosophy · Art Aesthetics · Comparative Philosophy West and Chinese · Eastern Philosophy . Islamic philosophy · Epistemology · Ethics · Hermeneutics · History of Religious Thought · History of Western Philosophy · Language Logic . (shrink)

Este artículo tiene como finalidad estudiar la noción de aserción en dos obras del siglo XVII francés: La Logique ou l’art de penser, de Antoine Arnauld y Pierre Nicole, y la Grammaire générale et raisonnée, de Antoine Arnauld y Claude Lancelot. Se ha dividido el artículo en dos apartados dedicados respectivamente a la concepción de Port-Royal acerca del juicio, y a la teoría del verbo. A lo largo de la reflexión en torno a estos importantes conceptos en la teoría del (...) lenguaje de Port-Royal, pretendemos probar que sus autores efectuaron la distinción entre contenido proposicional y actitud proposicional antes de que Frege la estableciera de forma sólida y definitiva. The present paper sets out to examine the notion of assertion within two French 17th century works: Antoine Arnauld and Pierre Nicole’s La Logique ou l’art de penser, and Antoine Arnauld and Claude Lancelot’s Grammaire générale et raisonnée. This article has been divided into two sections. The first section is devoted to the Port-Royalian doctrine about judgment; the second section analyzes the theory of verb. On our account of these important notions of Port-Royal’s theory of language, we intend to prove that its authors had made out the distinction between propositional content and propositional attitude before Frege could set it forth in a solid and definite way. (shrink)

El artículo plantea la actualidad y pertinencia de la Filosofía de la información de Luciano Floridi, considerada a la luz de las revoluciones científicas de Occidente y de la instauración de nuevos paradigmas, tanto en las ciencias como en la filosofía. La analogía con el “giro matemático” de la Modernidad permite establecer el alcance revolucionario de la obra de Floridi, cuya aceptación implicará superar el obstáculo epistemológico del escolasticismo, en función del dinamismo histórico inherente al progreso científico.