This volume will be of particular interest to researchers working in the history, and in the philosophy, of logic and mathematics, and more generally, to ...

Gottlob Frege’s Grundgesetze der Arithmetik (Basic Laws of Arithmetic, Vol. I/II; 1893/1903) is a modern classic. Since the 1930s it has belonged to an exclusive class of only eleven works in the history of symbolic logic, which contain the ‘first appearance of a new idea of fundamental importance’ [Church, 1936, p. 122], and its author is the only one whose other major works — Begriffsschrift (1879) and Die Grundlagen der Arithmetik (1884) — also belong to this distinguished group. Together with (...) the seminal paper ‘Über Sinn und Bedeutung’ these three monographs represent the essential contributions to one of the most fascinating foundational projects in mathematics, then and now. For decades Frege struggled with the question, ‘how are we to apprehend logical objects, in particular, the numbers? What justifies us in acknowledging numbers as objects?’ [Frege, 2013, ‘Afterword’, p. 265]. His favourite answer, for a long time, was that arithmetic is a complex branch of logic. But since there is no logicism without logic, Frege started in Begriffsschrift with the invention of a nearly perfect formalization of higher-order classical predicate logic. To discover how far we can get in arithmetic by analytic means alone, it was even necessary to clarify the semantic character of the concept of number. This was done in a marvellous way by Frege five years later, in Grundlagen. The next step was nothing less than the complete execution of his logicist project, a monumental undertaking; and it is well known that here Frege failed, due to Russell’s derivation of the antinomy in 1902. But, despite the contradiction, Grundgesetze contains Frege’s legacy to logicism, which became more and more attractive. (shrink)

Though the divide between reason-based and causal-explanatory approaches in psychiatry and psychopathology is old and deeply rooted, current trends involving multi-factorial explanatory models and evidence-based approaches to interpersonal psychotherapy, show that it has already been implicitly bridged. These trends require a philosophical reconsideration of how reasons can be causes. This paper contributes to that trajectory by arguing that Donald Davidson’s classic paradigm of 1963 is still a valid option.

Eine vollständige Darstellung von Edmund Husserls Verhältnis zu Gottlob Frege steht noch aus, so dass es nicht verwundert, einige Missverständnisse, dieses Verhältnis betreffend, im Umlauf zu finden. Selbst scheinbar längst überwundene systematische Dogmen tauchen wieder auf, so z.B. die Auffassung, dass Husserl nicht nur entscheidend von Gottlob Frege beeinflusst wurde, sondern darüber hinaus auch seine schärfste Frege-Kritik 1891 zurückgenommen habe. Mein Beitrag enthält eine überwiegend historisch vorgehende Entgegnung auf solche fälschlich vertretenen Ansichten wie sie sich auch in dem neu erschienenen (...) und mit vielen dokumentarischen Belegen versehenen Frege-Kommentarbuch von W. Künne finden. Die wichtigsten Argumente, die in diesem Buch gegen Husserl gerichtet werden, stützen sich auf Stellen in Husserls Frühwerk, die zwar sehr aufschlussreich für die Beurteilung des philosophischen und menschlichen Habitus Husserls in den 1890er Jahre sind, nicht aber Künnes Thesen stützen oder gar beweisen können. Die als zurückgenommene Frege-Kritik verstandene Selbstkritik Husserls betrifft jedoch nach meinen Darlegungen gerade nicht die Kritik, die er an Freges Buch Grundlagen der Arithmetik geübt hatte, sondern seine eigene systematische Stellungnahme hinsichtlich der Begründung der Arithmetik. Ausgehend von dieser Einsicht werde ich auf ein wichtiges Spezifikum von Husserls Erstlingswerk (Philosophie der Arithmetik) aufmerksam machen, das voreiligen Interpretationen einen Riegel vorschiebt: Dieses Buch ist ein Mosaik aus Einsichten verschiedener Arbeits- und Denkperioden des Verfassers, die sich vor allem auch in dem zweifachen Begriff der Äquivalenz zeigen. Dies knüpft an einen langen geschichtlichen Entwicklungsprozess an, der in eine von Bolzano, Lotze, Brentano und Carl Stumpf geprägte Tradition zurückführt und das Problem der Unterscheidung zwischen Sinn und Gegenstand eines Aktes betrifft. (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)

ABSTRACT Recently, the content/force distinction has had a bad press. It has been argued that the distinction is not properly motivated and that it makes the problem of the unity of the proposition intractable. I will argue that Frege’s version of the content/force distinction is immune from these objections. In order to do so, I will reconstruct his argument that ‘the nature of a question’ requires a distinction between force and content. I will answer the concern about the unity of (...) the proposition by outlining how the distinction can be combined with a Fregean account of the unity of thought. (shrink)

The two different layers of logical theory—epistemological and ontological—are considered and explained. Special attention is given to epistemic assumptions of the kind that a judgement is granted as known, and their role in validating rules of inference, namely to aid the inferential preservation of epistemic matters from premise judgements to conclusion judgement, while ordinary Natural Deduction assumptions serve to establish the holding of consequence from antecedent propositions to succedent proposition.

Why did Frege offer only proper names as examples of presupposition triggers? Some scholars claim that Frege simply did not care about the full range of presuppositional phenomena. This paper argues, in contrast, that he had good reasons for employing an extremely narrow notion of ‘Voraussetzung’. On Frege’s view, many devices that are now construed as presupposition triggers either express several thoughts at once or merely ‘illuminate’ a thought in a particular way. Fregean presuppositions, in contrast, are essentially tied to (...) names. (shrink)

This paper offers a detailed reconstruction of Frege’s theory of side-thoughts and its relation to other parts of his pragmatics, most notably to the notion of colouring, to the notion of presupposition, and to his implicit notion of multi-propositionality. I also highlight some important differences between the subsemantic categories employed by Frege and those used in contemporary pragmatics.

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)

This paper concerns Bertrand Russell’s changing views on negative judgement. ‘Negative judgement’ is considered in the context of three theories of judgement that Russell put forth at different times: a dual relation theory ; a multiple relation theory ; a psychological theory of judgement. Four issues are singled out for a more detailed discussion: quality dualism versus quality monism, that is, the question whether judgement comes in two kinds, acceptance and rejection, or whether there is only one judgement-quality ; the (...) structure of negative judging; the problem of truth-making for negative facts; the different roles of ‘fact’ in Russell’s theories of truth. What emerges from the discussion is a rough chronology of Russell’s views on negative judgement during the period from 1903 to 1948. (shrink)

ABSTRACT In “Die Verneinung”, Frege discusses two types of negation, a semantic one and a pragmatic one. Semantic negation consists in the application of the logical function denoted by ‘it is false that p’ to a thought, and pragmatic negation in the act of asserting or judging a thought as false. According to the standard interpretation, Frege does not acknowledge pragmatic negation, because it is logically redundant. He therefore rejects the classical dualistic view that both truth and falsity are qualities (...) of judgement and adopts instead the monistic view that to judge is always to recognize a thought as true. My aim in this paper is to show that this interpretation cannot be sustained. Though Frege does not endorse the classical view, he defends a dualistic conception that is characterized by the claim that judging is a binary operation that contains both the act of recognizing a thought as true and the act of rejecting the opposite thought as false. To make this interpretation plausible, Frege’s dualistic remarks on negation in three posthumous writings, which have received little attention so far, are analyzed in detail and their background is reconstructed. It is argued that Frege acknowledges negative judgements to account for the epistemic role of the act of judgement in the acquisition of knowledge. RESUMO Frege discute dois tipos de negação em “Die Verneinung” : uma semântica e uma pragmática. Negação semântica consiste na aplicação da função lógica denotada por ‘é falso que p’ para um pensamento, e negação pragmática no ato de afirmar ou julgar um pensamento como falso. De acordo com a interpretação padrão, Frege não reconhece a negação pragmática, porque ela é logicamente redundante. Assim, ele rejeita a visão dualística clássica de que tanto verdade quanto falsidade são qualidades de julgamento e, em vez disso, adota a visão monística de que julgar é sempre reconhecer um pensamento como verdade. Meu objetivo neste artigo é mostrar que tal interpretação não pode ser sustentada. Apesar de Frege não endossar a visão clássica, ele defende um conceito dualista que é caracterizado pela afirmação de que julgar é uma operação binária que contém tanto o ato de reconhecer um pensamento como verdade, quanto o ato de rejeitar o pensamento oposto como falso. Para tornar essa interpretação plausível, Frege faz observações dualísticas sobre a negação em três escritos póstumos, que têm recebido pouca atenção até o presente, são analisadas em detalhe e seu background é reconstruído. Argumenta-se que Frege reconhece o julgamento negativo para explicar o papel epistêmico do ato de julgar na aquisição de conhecimento. (shrink)

This entry introduces the reader to the main ideas in Frege's philosophy of logic, mathematics, and language.

This paper presents a passage on truth from "Der Gedanke" and comments on its content and use in the classroom.

In the last forty years Dummett, Hanks, Künne, and Bobzien have claimed that when Frege wrote ‘Über Sinn und Bedeutung’, he thought that the sense of a sentence-question [Satzfrage] was not a thought [Gedanke] ((Dummett 1981: 307–308); (Hanks 2007: 142–143); (Künne 2010: 427–429); (Bobzien 2021: 163–164)). Recently, Textor has claimed that when Frege wrote ‘Über Sinn und Bedeutung’, he thought that the sense of a sentence-question was not a question [Frage] (Textor 2021: 227 fn.2). I think it is possible that (...) when Frege wrote ‘Über Sinn und Bedeutung’, he thought that the sense of a sentence-question was a question and a thought. To show that this possibility should not be overlooked, I have written a dialogue in which Frege responds to Dummett, Hanks, Künne, Bobzien, and Textor. -/- Bobzien seems to think that when Frege wrote ‘Die Verneinung’, he thought that the sense of a sentence-question was not a question (Bobzien 2021: 163–165). I think it is possible that when Frege wrote ‘Die Verneinung’, he thought that the sense of a sentence-question was a question and a thought. Hence, I have also written the dialogue to show that this possibility should not be overlooked either. (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.

Georgalis claimed that when Frege wrote ‘Über Sinn und Bedeutung’ Frege thought that the indirect [ungerade] sense of an expression was identical to its normal [gewöhnlich] sense (Georgalis 2022: e.g. 4, 5, 13). In this paper, I present five arguments for the falsity of Georgalis’ claim which are based on three pieces of apparent counterevidence: a passage from Frege’s letter to Russell dated 28.12.1902; a passage from Frege’s letter to Russell dated 20.10.1902; and a passage from ‘Über Sinn und Bedeutung’. (...) I outline possible counter-arguments and responses. (shrink)

G. F. Stout is famous as an early twentieth century proselyte for abstract particulars, or tropes as they are now often called. He advanced his version of trope theory to avoid the excesses of nominalism on the one hand and realism on the other. But his arguments for tropes have been widely misconceived as metaphysical, e.g. by Armstrong. In this paper, I argue that Stout’s fundamental arguments for tropes were ideological and epistemological rather than metaphysical. He moulded his scheme to (...) fit what is actually given to us in perception, arguing that our epistemic practices would break down in an environment where only universals were given to us. (shrink)

In this paper I apply a well known tension between cognitive and semantic aspects in Frege’s notion of sense to his treatment of indexicals. I first discusses Burge’s attack against the identification of sense and meaning, and Kripke’s answer supporting such identification. After showing different problems for both interpreters, the author claims that the tension in Frege’s conception of sense (semantic and cognitive) accounts for some shortcomings of both views, and that considering the tension helps in understanding apparently contradictory Fregean (...) claims about sameness of sense of sentences with indexicals. I conclude that the Fregean notion of sense, also in its cognitive aspect, cannot be reduced to linguistic meaning, and that the Fregean tension between two notions of sense may also explain the discussion Frege gives on the indexical “I”, proposing to develop a picture of indexicals as hidden complex demonstratives, as originally suggested by Burge. (shrink)