Gottlob Frege

itruses, or that there is a traffic congestion on Brooklyn Bridge (at some time). We make assertions to share information, coordinate our actions, defend arguments, and communicate our beliefs and desires. Because of its central role in communication, assertion has been investigated in several disciplines. Linguists, philosophers of language, and logicians rely heavily on the notion of assertion in theorizing about meaning, truth and inference. -/- The nature of assertion and its relation to other speech acts and linguistic phenomena (implicatures, (...) presuppositions, etc.) have been subject to much controversy. This entry will situate assertion within speech act theory and pragmatics more generally, and then go on to present the current main accounts of assertion. (shrink)

At the turn of the century, Gottlob Frege and Edmund Husserl both participated in the discussion concerning the foundations of logic and mathematics. Since the 1960s, comparisons have been made between Frege's semantic views and Husserl's theory of intentional acts. In quite recent years, new approaches to the two philosophers' views have appeared. This collection of articles opens with the first English translation of Dagfinn Føllesdal's early classic on Husserl and Frege of 1958. The book brings together a number of (...) new contributions by well-known authors and gives a survey of recent developments in the field. It shows that Husserl's thought is coming to occupy a central role in the philosophy of logic and mathematics, as well as in the philosophy of mind and cognitive science. The work is primarily meant for philosophers, especially for those working on the problems of language, logic, mathematics, and mind. It can also be used as a textbook in advanced courses in philosophy. (shrink)

"By looking at Frege's lectures on logic through the eyes of the young Carnap, this book casts new light on the history of logic and analytic philosophy. As two introductory essays by Gottfried Gabriel and by Erich H. Reck and Steve Awodey explain, Carnap's notes allow us to better understand Frege's deep influence on Carnap and analytic philosophy, as well as the broader philosophical matrix from which both continental and analytic styles of thought emerged in the 20th century."--BOOK JACKET.

Widespread interest in Frege's general philosophical writings is, relatively speaking, a fairly recent phenomenon. But it is only very recently that his philosophy of mathematics has begun to attract the attention it now enjoys. This interest has been elicited by the discovery of the remarkable mathematical properties of Frege's contextual definition of number and of the unique character of his proposals for a theory of the real numbers. This collection of essays addresses three main developments in recent work on Frege's (...) philosophy of mathematics: the emerging interest in the intellectual background to his logicism; the rediscovery of Frege's theorem; and the reevaluation of the mathematical content of The Basic Laws of Arithmetic. Each essay attempts a sympathetic, if not uncritical, reconstruction, evaluation, or extension of a facet of Frege's theory of arithmetic. Together they form an accessible and authoritative introduction to aspects of Frege's thought that have, until now, been largely missed by the philosophical community. (shrink)

Resumen En esta discusión expongo algunas objeciones a las siguientes tesis de Velázquez 2020: 1) que tanto Descartes como Frege sostienen que las entidades aritméticas son irreductibles a procesos empíricos; 2) que, en el caso de Descartes, dichas entidades son “perennes, inherentes a la propia constitución y funcionamiento de la mente” y 3) que Frege impugnó la filosofía matemática de Mill por psicologista. Sostengo que la segunda tesis no es, per se, controversial, pero que sí lo es en el contexto (...) del artículo de Velázquez.In this discussion I present objections to the following theses in Velázquez 2020: 1) that both Descartes and Frege maintain that arithmetic entities are irreducible to empirical processes; 2) that, in the case of Descartes, these entities are “perennial, inherent to the very constitution and functioning of the mind”, and 3) that Frege contested Mill’s mathematical philosophy for being psychologistic. I argue that the second thesis is not, per se, controversial, but that it is controversial in the context of Velázquez’s article. (shrink)

I take issue with Glezakos’s explanation of why Frege’s puzzle is un-puzzling. On her view, Frege’s statement – how can sentences of the form a=a and a=b, if true, differ in cognitive value if they express the same semantic content/are made true by the same object’s self-identity? – should not be considered any puzzling either because it is on the whole circular, or because, neutrally stated, it cannot even be set up. I argue against this that if, as she takes (...) it, Frege’s statement is “problematic” it is not for the reasons she gives, but because it rests upon a couple of questionable assumptions: i) there is no ambiguity as to which aspect of the sign (in its relation to the referent) is relevant to a neutral statement of the puzzle ii) it is of the (sentence) forms themselves one may sensibly say they differ in cognitive value. (shrink)

Logical Investigations (notably, The Thought) is one of the works wherein Frege voices his hostility to psychologism in logic, science, and semantics. Such hostility lies, arguably, behind his threefold conceptual distinction between thought (Gedanke), thinking (Denken), and ideas (Vorstellungen). In this essay I investigate, to begin with, Frege’s motivations for drawing the distinction and keeping thinking episodes (one of the meanings of ‘thoughts’ in English) out of the picture. It turns out, or so I argue, that psychologism threatens, on Frege’s (...) view, to destroy the objectivity requirement by which thoughts are defined as answerable contents. I then draw a connection between this feature in Frege’s view and an on-going debate in philosophy of mind and language over the nature of world-directed thoughts and show that the feature lies at the heart of the singularist stance. Finally, I show that, despite Frege’s own hostility to all that bears the mark of the subjective in logic, science, and semantics, a psychological argument can be mounted in support of singularism (i.e. the view that some of our thoughts are about particulars qua particulars) using his disparaged notion of idea (Vorstellung) and that, appearances notwithstanding, the argument is compatible with the objectivity requirement on answerable thought-contents. (shrink)

My aim in this paper is to show in what sense one might characterize ‘analytic philosophy’. In its first part I present some meta-philosophical ideas about the topic and in its following and more substantial parts I develop, as an example of what is being said, one and only one philosophical problem in the Philosophy of Language. The philosophical problem I consider, the so called ‘identity problem’ or ‘Frege Puzzle’ was first advanced by Frege and was treated and developed by (...) several philosophers during the 20th Century. I consider some of the main solutions for the puzzle trying to show by philosophical considerations what I had previously said by meta-philosophical ideas about analytic philosophy. (shrink)

We note that a plural version of logicism about arithmetic is suggested by the standard reading of Hume's Principle in terms of `the number of Fs/Gs'. We lay out the resources needed to prove a version of Frege's principle in plural, rather than second-order, logic. We sketch a proof of the theorem and comment philosophically on the result, which sits well with a metaphysics of natural numbers as plural properties.

According to the Bad Company objection, the fact that Frege’s infamous Basic Law V instantiates the general definitional pattern of higher-order abstraction principles is a good reason to doubt the soundness of this sort of definitions. In this paper I argue against this objection by showing that the definitional pattern of abstraction principles – as extrapolated from §64 of Frege’s Grundlagen– includes an additional requirement (which I call the specificity condition) that is not satisfied by the Basic Law V while (...) is satisfied by other higher-order abstractions such as Hume’s Principle. I also show that the failure of this additional requirement in the case of Basic Law V is engendered by an essential feature of Frege’s conception of logic and thus that Frege himself should not have regarded the Basic Law V as a definition by abstraction. (shrink)

نگاهی بر استدلال‌های دونالد دیویدسون در باب ضرورت زبان برای اندیشه .

In Begriffsschrift, Frege presented a formal system and used it to formulate logical definitions of arithmetical notions and to deduce some noteworthy theorems by means of logical axioms and inference rules. From a contemporary perspective, Begriffsschrift’s deductions are, in general, straightforward; it is assumed that all of them can be reproduced in a second-order formal system. Some deductions in this work present—according to this perspective—oddities that have led many scholars to consider it to be Frege’s inaccuracies which should be amended. (...) In this paper, we continue with the analysis of Begriffsschrift’s logic undertaken in an earlier work and argue that its deductive system must not be reconstructed as a second-order calculus. This leads us to argue that Begriffsschrift’s deductions do not need any correction but, on the contrary, can be explained in coherence with a global reading of this work and, in particular, with its fundamental distinction between function and argument. (shrink)

Frege argued for the force-content distinction not only by appealing to the logical and fictional contexts which are most closely associated with the “Frege point", but also based on the fact that an affirmative answer to a yes-no question constitutes an assertion. Supposedly this is only intelligible if the question contains a forceless thought or proposition which an affirmative answer then asserts. Against this I argue that this fact more readily supports the view that questions operate on assertions and other (...) forceful acts themselves. Force is neither added to propositions as on the traditional view, nor is it cancelled as has recently been proposed. Rather higher-level acts such as questioning, but also e.g. conditionalizing, embed and present assertoric or directive acts that are forceful and committal, while suspending commitment to them. The Frege point confounds different varieties of force and the question whether something is merely presented for consideration with the question what is so presented. Force is representational: through assertoric and directive force indicators subjects non-conceptually present positions of theoretical or practical knowledge, while interrogative acts indicate positions of wondering which strive for such knowledge. (shrink)

Due programmi diversi si intersecano nel lavoro di Frege sui fondamenti dell’aritmetica: • Logicismo: l’aritmetica `e riducibile alla logica; • Estensionalismo: l’aritmetica `e riducibile a una teoria delle estensioni. Sia nei Fondamenti che nei Principi, Frege articola l’idea che l’aritmetica sia riducibile a una teoria logica delle estensioni.

Call a family F of subsets of a set E inductive if ∅ ∈ F and F is closed under unions with disjoint singletons, that is, if ∀X∈F ∀x∈E–X(X ∪ {x} ∈ F]. A Frege structure is a pair (E.

: Frege's philosophical writings, including the "logistic project," acquire a new insight by being confronted with Kant's criticism and Wittgenstein's logical and grammatical investigations. Between these two points a non-formalist history of logic is just taking shape, a history emphasizing the Greek and Kantian inheritance and its aftermath. It allows us to understand the radical change in rationality introduced by Gottlob Frege's syntax. This syntax put an end to Greek categorization and opened the way to the multiplicity of expressions producing (...) their own intelligibility. This article is based on more technical analyses of Frege which Claude Imbert has previously offered in other writings (see references). (shrink)

Unless you are a Frege scholar, or a philosopher of mathematics, if you are familiar at all with Frege’s work, you are most likely familiar with his groundbreaking work in the philosophy of language. You might know that Frege was a mathematician who sought to establish the covertly logical subject matter of arithmetic, a project whose demands drove Frege to his logical investigations and reflections on language. But most likely the connection between Frege’s mathematical research and his philosophy of language (...) remains elusive for you. (shrink)

avant propos This paper is basically Keenan (1992) augmented by some new types of properly polyadic quantification in natural language drawn from Moltmann (1992), Nam (1991) and Srivastav (1990). In addition I would draw the reader's attention to recent mathematical studies of polyadic quantiicationz Ben-Shalom (1992), Spaan (1992) and Westerstahl (1992). The first and third of these extend and generalize (in some cases considerably) the techniques and results in Keenan (1992). Finally I would like to acknowledge the stimulating and constructive (...) discussions ofthe earlier paper with many scholars, notably Dorit Ben-Shalom, Jaap van der Does, Hans Kamp, Uwe Mormich, Arnim von Stechow, Mats Rooth, and Ede Zimmermann. And I repeat here the acknowledgment in the earlier paper to Jim Lambek, Ed Stabler and two anonymous referees for Linguistics and Philosophy (the latter responsible for substantial improvements in the proofs - see footnote 10). (shrink)

1. There is only one rule of inference, modus ponens. This is true both in the presentations of Begriffsschrift and Grundgesetze. There are other ways of making transitions between propositions in proofs, but these are never labeled by Frege “rules of inference.” These pertain to scope of quantification, parsing of formulas, introduction of definitions, conventions for the use and replacement of the various letters, and certain structural reorganizations, ; cf. the list in Gg §48.

A frege-Russell cardinal number is a maximal class of equinumerous classes. Since anything can be numbered, A frege-Russell cardinal should contain classes whose members are cardinal numbers. This is not possible in standard set theories, Since it entails that some classes are members of members of themselves. However, A consistent set theory can be constructed in which such membership circles are allowed and in which, Consequently, Genuine frege-Russell cardinals can be defined.

Existuje překvapivě málo knih, které by se pokoušely o syntetizující pohled na analytickou filosofii. Je ovšem pravda, že ve druhé polovině našeho století se soubor filosofů, kteří se k analytické filosofii hlásí nebo kteří k ní bývají řazeni, stává natolik různorodý, že se jakákoli syntéza stává problematickou; překvapivě málo syntetizujících prací existuje ale i o ‘klasické’ analytické filosofii, to jest o analytické filosofii období zhruba od konce devatenáctého století do poloviny století dvacátého. Dejnožkova kniha je jednou z těch mála, které (...) se o něco takového pokouší, a to je třeba přivítat. Dejnožka se ovšem nesnaží podat všestranný rozbor názorů klasiků analytické filosofie; soustředí se pouze jeden aspekt jejich učení, totiž na jejich ontologii. Hned v úvodu své knihy k tomu vysvětluje, jaké opodstatnění může mít hovořit o ontologii u takového druhu filosofie, která se programově distancuje od metafyziky. Podle něj je tomu tak, že i když se někteří analytičtí filosofové někdy více či méně úspěšně vyhýbali otázkám metafyzickým (to jest otázkám po nejzákladnějších kategoriích bytí), ontologickým otázkám (to jest otázkám po povaze bytí jako takového) se v podstatě vyhnout nelze. A Dejnožka se snaží ukázat, že klasikové analytické filosofie se těmito otázkami zabývali mnohdy velice do hloubky. To je patrné zejména u Frega a Russella, kterým autor věnuje největší pozornost; avšak k těm, kteří podle Dejnožky berou ústřední otázku ontologie za svou, řadí Dejnožka i Wittgensteina i Quina (jimž se však věnuje na pouze velice omezeném prostoru - každému asi na dvanácti stránkách). (shrink)

For both Gottlob Frege and Bertrand Russell, providing a philosophical account of the concept of number was a central goal, pursued along similar logicist lines. In the present paper, I want to focus on a particular aspect of their accounts: their definitions, or reconstructions, of the natural numbers as equivalence classes of equinumerous classes. In other words, I want to examine what is often called the "Frege-Russell conception of the natural numbers" or, more briefly, the Frege-Russell numbers. My main concern (...) will be to determine the precise sense in which this conception was, or could be, meant to constitute an analysis.1 I will be mostly concerned with Frege’s views on the matter; but Russell will come up along the way, for illustration and comparison, as will some recent neo-Fregean proposals and results. The structure of the paper is as follows: In the first section, I sketch Frege's general approach. Next, I differentiate several kinds, or modes, of analysis, as further background. In the third section, I zero in on the equivalence class construction, raising the question of why it might, from a Fregean point of view, be seen as 'the right' construction, thus as an analysis in a strong sense. In the fourth section, I provide a contrasting, more conventionalist view of the matter, often associated with the Carnapian notion of explication, and expressed in some remarks by Russell. I then discuss the motivation for the Frege-Russell numbers in more depth. In the sixth section, I introduce a neo-Fregean alternative, to be examined along similar lines. Finally, I reflect further on the significance of the kinds of arguments available in this connection. (shrink)

Frege's main contributions to logic and the philosophy of mathematics are, on the one hand, his introduction of modern relational and quantificational logic and, on the other, his analysis of the concept of number. My focus in this paper will be on the latter, although the two are closely related, of course, in ways that will also play a role. More specifically, I will discuss Frege's logicist reconceptualization of the natural numbers with the goal of clarifying two aspects: the motivations (...) for its core ideas; the step-by-step development of these ideas, from Begriffsschrift through Die Grundlagen der Arithmetik and Grundgesetze der Arithmetik to Frege's very last writings, indeed even beyond those, to a number of recent "neo-Fregean" proposals for how to update them. One main development, or break, in Frege's views occurred after he was informed of Russell's antinomy. His attempt to come to terms with this antinomy has found some attention in the literature already. It has seldom been analyzed in connection with earlier changes in his views, however, partly because those changes themselves have been largely ignored. Nor has it been discussed much in connection with Frege's basic motivations, as formed in reaction to earlier positions. Doing both in this paper will not only shed new light on his response to Russell's antinomy, but also on other aspects of his views. In addition, it will provide us with a framework for comparing recent updates of these views, thus for assessing the remaining attraction of Frege's general approach. I will proceed as follows: In the first part of the paper (§1.1 and §1.2), I will consider the relationship of Frege's conception of the natural numbers to earlier conceptions, in particular to what I will call the "pluralities conception", thus bringing into sharper focus his core ideas and their motivations. In the next part (§2.1 and §2.2), I will trace the order in which these ideas come up in Frege's writings, as well as the ways in which his position gets modified along the way, both before and after Russell's antinomy.. (shrink)

Since there are non-sortal predicates Frege’s attempt to derive Arithmetic from Logic stumbles at its very first step. There are properties without a number, so the contingency of that condition shows Frege’s definition of zero is not obtainable from Logic. But Frege made a crucial mistake about concepts more generally which must be remedied, before we can be clear about those specific concepts which are numbers.

The four volumes of this collection bring together some of the major contributions to the literature on Gottlob Frege (1848-1925), one of the most formative influences on the course of philosophy during the last hundred years. The first volume provided general assessments of Frege's work and examined its historical context. The present volume deals with Frege's contributions to logic and the foundations of mathematics. The essays are arranged in order of their first publication, providing insight into the historical evolution of (...) the Frege literature. Annotation copyright by Book News, Inc., Portland, OR. (shrink)

There can be no doubt about the value of Frege's contributions to the philosophy of mathematics. First, he invented quantification theory and this was the first step toward making precise the notion of a purely logical deduction. Secondly, he was the first to publish a logical analysis of the ancestral R* of a relation R, which yields a definition of R* in second-order logic.1 Only a narrow and arid conception of philosophy would exclude these two achievements. Thirdly and very importantly, (...) the discussion in §§58-60 of the G r u n d l a g e n defends a conception of mathematical existence, to be found in Cantor (1883) and later in the writings of Dedekind and Hilbert, by basing it upon considerations about meaning which have general application, outside mathematics.2.. (shrink)

A Frege proof systemFis any standard system of prepositional calculus, e.g., a Hilbert style system based on finitely many axiom schemes and inference rules. An Extended Frege systemEFis obtained fromFas follows. AnEF-sequence is a sequence of formulas ψ1, …, ψκsuch that eachψiis either an axiom ofF, inferred from previous ψuand ψv by modus ponens or of the formq↔ φ, whereqis an atom occurring neither in φ nor in any of ψ1,…,ψi−1. Suchq↔ φ, is called an extension axiom andqa new extension (...) atom. AnEF-proof is anyEF-sequence whose last formula does not contain any extension atom. In [12], S. A. Cook and R. Reckhow proved that the pigeonhole principlePHPhas a simple polynomial sizeEF-proof and conjectured thatPHPdoes not admit polynomial sizeF-proof. In [5], S. R. Buss refuted this conjecture by furnishing polynomial sizeF-proof forPHP. Since then the important separation problem of polynomial sizeFand polynomial sizeEFhas not shown any progress.In [11], S. A. Cook introduced the systemPV, a free variable equational logic whose provable functional equalities are ‘polynomial time verifiable’ and showed that the metamathematics ofFandEFcan be developed inPVand the soundness ofEFproved inPV. In [3], S. R. Buss introduced the first order systemand showed thatis essentially a conservative extension ofPV. There he also introduced a second order system. (shrink)

In this paper, I consider two curious subsystems ofFrege's Grundgesetze der Arithmetik: Richard Heck's predicative fragment H, consisting of schema V together with predicative second-order comprehension (in a language containing a syntactical abstraction operator), and a theory T in monadic second-order logic, consisting of axiom V and 1 1-comprehension (in a language containing anabstraction function). I provide a consistency proof for the latter theory, thereby refuting a version of a conjecture by Heck. It is shown that both Heck and T (...) prove the existence of infinitely many non-logical objects (T deriving,moreover, the nonexistence of the value-range concept). Some implications concerning the interpretation of Frege's proof of referentiality and the possibility of classifying any of these subsystems as logicist are discussed. Finally, I explore the relation of T toCantor's theorem which is somewhat surprising. (shrink)

This survey article describes Frege's celebrated foundational work against the context of other late nineteenth century approaches to introducing mathematically novel "extension elements" within both algebra and geometry.

This paper offers an explanation of how philosophy of science in the second half of the 20th century came to be so conspicuously silent on the problem of how to explain the applicability of mathematics. It examines the idea of the early logicists that the analyticity of mathematics accounts for its applicability, and how this idea was transformed during Carnap's efforts to establish a consistent and substantial philosophy of mathematics within the larger framework of Logical Empiricism. I argue that at (...) the end point of this development, philosophical discussion of the applicability problem was terminated although important aspects of the logicists' original response to the applicability problem had had to be sacrificed along the way. (shrink)

The paper explores what it could mean to speak of love as involving a delight in ‘the simple actuality’ of another, or, as Buber does, of the ‘touchable’ human being as ‘unique and devoid of qualities’. Developing strands in Merleau-Ponty’s treatment of perception, it is argued that the relation between recognising this as a particular individual and recognising particular qualities in her may be close to the reverse of what might be supposed: a recognition of this distinctive smile being dependent (...) on a recognition of who this is. The fundamental place of particulars, as opposed to kinds, in our thought about those we know and care for is developed in part through a phenomenological treatment of our perception of faces. That treatment is set in a context of the justification of our judgements about who someone is, and is linked with a critique of treatments of proper names of individuals in the spirit of Frege. It is in our speaking to those we know that we find a relation to a particular that is direct—not mediated by a description of its properties—that Russell sought in ‘knowledge by acquaintance’. (shrink)

In this essay, I argue that Frege plagiarized the Stoics --and I mean exactly that-- on a large scale in his work on the philosophy of logic and language as written mainly between 1890 and his death in 1925 (much of which published posthumously) and possibly earlier. I use ‘plagiarize' (or 'plagiarise’) merely as a descriptive term. The essay is not concerned with finger pointing or casting moral judgement. The point is rather to demonstrate carefully by means of detailed evidence (...) that there are numerous (over a hundred) and extensive parallels both in formulation and --more importantly-- in content between the Stoics and Frege, parallels so plentiful that one would be hard pressed to brush them off as coincidence. These parallels include several that appear to occur in no other modern works that were published before Frege’s own and were accessible to him. Additionally, a cluster of corroborating historical data is adduced to support the suggestion, showing how easy it would have to been for Frege to plagiarize the Stoics. This (first) part of the essay is easy to read and vaguely entertaining, or so I hope. (shrink)

Diese Arbeit stellt Freges Denken in seiner Entwicklung von den Anfängen bis zum Auftreten des Widerspruch dar. Ausführlich behandelt sind die Begriffsschrift, die Erläuterungsschriften dazu, die Grundlagen der Arithmetik sowie die Texte im Übergang zu den Grundgesetzen der Arithmetik, ein- schließlich der klassischen Aufsätze Funktion und Begriff, Über Sinn und Bedeutung und Über Begriff und Gegenstand. Die Texte werden nach Chronologie und Stellung zueinander präzise aufgeschlüsselt; auch die zeitgenössischen Rezensionen und Freges wissenschaftliches Umfeld werden berücksichtigt. Freges Werk wird dadurch in (...) seiner beeindruckenden Zielstrebigkeit, Geschlossenheit und Tiefe sichtbar. Sein Zentrum ist die radikale Neufassung der Logik, ausgehend von der Grundunterscheidung von Begriff und Gegenstand, die zunächst eher unauffällig über die Zerfällung des Urteils in Funktion und Argument eingeführt und mit f(a) notiert wird. Zusammen mit der Einführung einer (Quantoren-)Notation, um die Allgemeinheit der Einsetzungen auf beiden Positionen einzuschränken, übertrifft Freges Logik die traditionelle, alle zeitgenössischen und etliche spätere an Präzision und Ausdruckskraft. Eben die grundsätzliche Trennung von Begriff und Gegenstand erweist sich aber für sein wissenschaftliches Hauptanliegen, die Ableitung der Arithmetik aus der Logik, als schwerwiegendes, letztlich nicht zu überwindendes Hindernis. Es gelingt ihm nicht, die Zahlen als „logische Gegenstände“ überzeugend einzuführen, und so zeigt er wider Willen die wesentliche Verschiedenheit von Logik und Arithmetik auf. (shrink)

In this symposium contribution I critically review the first two chapters, on Frege, in Volume 1 of The Analytic Tradition in Philosophy by Scott Soames.