In his “The Foundations of Mathematics”, Ramsey attempted to marry the Tractarian idea that all logical truths are tautologies and vice versa, and the logicism of the Principia. In order to complete his project, Ramsey was forced to introduce propositional functions in extension (PFEs): given Ramsey's definitions of 1 and 2, without PFEs even the quantifier-free arithmetical truth that 1 ≠ 2 is not a tautology. However, a number of commentators have argued that the notion of PFEs is incoherent. (...) This response was first given by Wittgenstein but has been best developed by Sullivan. While I agree with Wittgenstein and Sullivan's common conclusion, I believe that even the most compelling of Sullivan's arguments is importantly mistaken and that Wittgenstein's remarks are too opaque to be left as the end of the matter. In this article I uncover the fault in Sullivan's argument and present an alternative criticism of PFEs which is Wittgensteinian in spirit without being too mystifying. (shrink)

The work of Bertrand Russell had a decisive influence on the emergence of analytic philosophy, and on its subsequent development. The prize-winning Russell scholar Peter Hylton presents here some of his most celebrated essays from the last two decades, all of which strive to recapture and articulate Russell's monumental vision. Relating his work to that of other philosophers, particularly Frege and Wittgenstein, and featuring a previously unpublished essay and a helpful new introduction, the volume will be essential for anyone engaged (...) with the history of twentieth-century ideas. (shrink)

Peter Geach has said that Russell's use of ‘propositional function’ is ‘hopelessly confused and inconsistent’. Geach is right, and attempts to say what exactly a Russellian propositional function is, or is supposed to be, are bound to end in frustration. Nevertheless, it may be worthwhile to pursue an account of propositional functions that accommodates a good deal of what Russell says about them and that can provide some of what he expected of them.

Russell discovered the classes version of Russell's Paradox in spring 1901, and the predicates version near the same time. There is a problem, however, in dating the discovery of the propositional functions version. In 1906, Russell claimed he discovered it after May 1903, but this conflicts with the widespread belief that the functions version appears in _The Principles of Mathematics_, finished in late 1902. I argue that Russell's dating was accurate, and that the functions version does not appear in (...) the _Principles_. I distinguish the functions and predicates versions, give a novel reading of the _Principles_, section 85, as a paradox dealing with what Russell calls _assertions_, and show that Russell's logical notation in 1902 had no way of even formulating the functions version. The propositional functions version had its origins in the summer of 1903, soon after Russell's notation had changed in such a way as to make a formulation possible. (shrink)

In this paper I describe the birth of Russell’s notion of a propositional function on 3 May 1902 and its immediate context and implications. In particular, I consider its significance in relation to the development of his views on analysis.

Wittgenstein's Tractatus carefully distinguished the concept all from\nthe notion of a truth-function, and thereby from the quantifiers.\nI argue that Wittgenstein's rationale for this distinction is lost\nunless propositional functions are understood within the context\nof his picture theory of the proposition. Using a model Tractatus\nlanguage, I show how there are two distinct forms of generality implicit\nin quantified Tractatus propositions. Although the explanation given\nin the Tractatus for this distinction is ultimately flawed, the distinction\nitself is a genuine one, and the forms of (...) generality that Wittgenstein\nindicated can be seen in the quantified sentences of contemporary\nlogic. (shrink)

Arguments are given against the thesis that properties and propositional functions are identical. The first shows that the familiar extensional treatment of propositional functions -- that, for all x, if f(x) = g(x), then f = g -- must be abandoned. Second, given the usual assumptions of propositional-function semantics, various propositional functions (e.g., constant functions) are shown not to be properties. Third, novel examples are given to show that, if properties were identified with propositional (...) functions, crucial fine-grained intensional distinctions would be lost. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:February 19, 2011 (11:48 am) E:\CPBR\RUSSJOUR\TYPE3002\russell 30,2 040 red.wpd Reviews 161 7 In, respectively, PaciWsm in Britain and Semi-Detached Idealists: the British Peace Movement and International Relations (Oxford: Oxford U. P., 2000). 8 See Monk 2: Chap. 13. FUNCTIONS OR PROPOSITIONAL FUNCTIONS? Alexander Paul Bozzo Philosophy / Marquette U. Milwaukee, wi 53233, usa [email protected] Michael Potter and Tom Ricketts, eds. The Cambridge Companion to Frege. Cambridge, uk: Cambridge (...) U. P., 2010. Pp. vii, 630. isbn 978-0-521-62479-4 (pb). £57.00; £21.99 (pb). us$38.99 (pb). February 19, 2011 (11:48 am) E:\CPBR\RUSSJOUR\TYPE3002\russell 30,2 040 red.wpd 162 Reviews 1 Frege: Philosophy of Mathematics (Cambridge, ma: Harvard U. P., 1991), p. 111. The paragraph contains an expression of Frege’s Context Principle and the need for Hume’s Principle as a criterion of identity in the deWnition of number. 2 There are in fact Wve stated goals. The others are: (iii) to serve as a reference work for students and non-specialists, (iv) to provide a route into the study of Frege historically and to any relevant contemporary concerns in the philosophies of logic, language, mathematics, and mind, and (v) to provide, for new readers, the most convenient detailed guide to Frege currently available. Gottlob Frege is widely recognized as one of the chief progenitors of mathematical logic and philosophy of languagez—zindeed, the importance attributed to Frege’s innovations is such that Michael Dummett, when reXecting on§62 of Frege’s Die Grundlagen der Arithmetik, feels compelled to remark that the paragraph therein is “arguably the most pregnant philosophical paragraph ever written.”1 Whether or not one agrees with Dummett on this point, the magnitude of Frege’s inXuence on the current philosophical landscape is incontestable. Frege revolutionized the then dominant Aristotelian conception of logic, introducing a formal language now recognized as the predicate calculus. Central to this end were Frege’s insights on quantiWcation, the notation that expressed it, the logicist project, and the extension of mathematical notions like function and argument to natural language. The long-awaited Cambridge Companion to Frege is a compendium of Fregean scholarship that rigorously explores these and similar topics; editors Thomas Ricketts and Michael Potter have compiled a comprehensive collection of fourteen essays that individually provide focused appraisals of a number of Frege’s most substantial insights. On the advice of this journal’s editor, I have limited my review to the connections (or rather dissimilarities ) that exist between Frege and Russell, relying exclusively on Peter Hylton ’s contribution to the collection, “Frege and Russell”. Following a brief consideration of the volume as a whole, I move immediately into a detailed explication of Hylton’s analysis. The volume includes among its goals the following two aims: (i) to provide, for advanced students and specialists, a conspectus of recent interpretation of Frege, and (ii) to dispel the intimidation felt by readers who confront a diUcult thinker.2 I single out these ambitions because they most clearly represent the volume’s strengths and shortcomings. Enthusiasts of Frege will not be disappointed by the multitude of rigorously and technically written essays, essays that contribute substantially and originally to the collective understanding of Frege and his work. For instance, Thomas Ricketts provides a thoughtful and thorough analysis—an analysis that moves well beyond mere explication—of Frege’s concept/object distinction, in particular its relevance for Frege’s Context Principle and logicism more generally. Similarly, Richard Heck addresses a number of central yet largely unexplored issues pertaining to the overall signiWcance of February 19, 2011 (11:48 am) E:\CPBR\RUSSJOUR\TYPE3002\russell 30,2 040 red.wpd Reviews 163 3 I strongly encourage that non-specialists augment The Cambridge Companion to Frege with Joan Weiner’s Frege Explained: from Arithmetic to Analytic Philosophy (Chicago : Open Court, 2004), one of the best available introductory texts on Frege. 4 The essay in fact was available as early as 2005 in Hylton’s Propositions, Functions, and Analysis: Selected Essays on Russell’s Philosophy (New York, ny: Oxford U. P., 2005). The editors of The Cambridge Companion to Frege partially... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:February 19, 2011 (11:48 am) E:\CPBR\RUSSJOUR\TYPE3002\russell 30,2 040 red.wpd Reviews 161 7 In, respectively, PaciWsm in Britain and Semi-Detached Idealists: the British Peace Movement and International Relations (Oxford: Oxford U. P., 2000). 8 See Monk 2: Chap. 13. FUNCTIONS OR PROPOSITIONAL FUNCTIONS? Alexander Paul Bozzo Philosophy / Marquette U. Milwaukee, wi 53233, usa [email protected] Michael Potter and Tom Ricketts, eds. The Cambridge Companion to Frege. Cambridge, uk: Cambridge (...) U. P., 2010. Pp. vii, 630. isbn 978-0-521-62479-4 (pb). £57.00; £21.99 (pb). us$38.99 (pb). February 19, 2011 (11:48 am) E:\CPBR\RUSSJOUR\TYPE3002\russell 30,2 040 red.wpd 162 Reviews 1 Frege: Philosophy of Mathematics (Cambridge, ma: Harvard U. P., 1991), p. 111. The paragraph contains an expression of Frege’s Context Principle and the need for Hume’s Principle as a criterion of identity in the deWnition of number. 2 There are in fact Wve stated goals. The others are: (iii) to serve as a reference work for students and non-specialists, (iv) to provide a route into the study of Frege historically and to any relevant contemporary concerns in the philosophies of logic, language, mathematics, and mind, and (v) to provide, for new readers, the most convenient detailed guide to Frege currently available. Gottlob Frege is widely recognized as one of the chief progenitors of mathematical logic and philosophy of languagez—zindeed, the importance attributed to Frege’s innovations is such that Michael Dummett, when reXecting on§62 of Frege’s Die Grundlagen der Arithmetik, feels compelled to remark that the paragraph therein is “arguably the most pregnant philosophical paragraph ever written.”1 Whether or not one agrees with Dummett on this point, the magnitude of Frege’s inXuence on the current philosophical landscape is incontestable. Frege revolutionized the then dominant Aristotelian conception of logic, introducing a formal language now recognized as the predicate calculus. Central to this end were Frege’s insights on quantiWcation, the notation that expressed it, the logicist project, and the extension of mathematical notions like function and argument to natural language. The long-awaited Cambridge Companion to Frege is a compendium of Fregean scholarship that rigorously explores these and similar topics; editors Thomas Ricketts and Michael Potter have compiled a comprehensive collection of fourteen essays that individually provide focused appraisals of a number of Frege’s most substantial insights. On the advice of this journal’s editor, I have limited my review to the connections (or rather dissimilarities ) that exist between Frege and Russell, relying exclusively on Peter Hylton ’s contribution to the collection, “Frege and Russell”. Following a brief consideration of the volume as a whole, I move immediately into a detailed explication of Hylton’s analysis. The volume includes among its goals the following two aims: (i) to provide, for advanced students and specialists, a conspectus of recent interpretation of Frege, and (ii) to dispel the intimidation felt by readers who confront a diUcult thinker.2 I single out these ambitions because they most clearly represent the volume’s strengths and shortcomings. Enthusiasts of Frege will not be disappointed by the multitude of rigorously and technically written essays, essays that contribute substantially and originally to the collective understanding of Frege and his work. For instance, Thomas Ricketts provides a thoughtful and thorough analysis—an analysis that moves well beyond mere explication—of Frege’s concept/object distinction, in particular its relevance for Frege’s Context Principle and logicism more generally. Similarly, Richard Heck addresses a number of central yet largely unexplored issues pertaining to the overall signiWcance of February 19, 2011 (11:48 am) E:\CPBR\RUSSJOUR\TYPE3002\russell 30,2 040 red.wpd Reviews 163 3 I strongly encourage that non-specialists augment The Cambridge Companion to Frege with Joan Weiner’s Frege Explained: from Arithmetic to Analytic Philosophy (Chicago : Open Court, 2004), one of the best available introductory texts on Frege. 4 The essay in fact was available as early as 2005 in Hylton’s Propositions, Functions, and Analysis: Selected Essays on Russell’s Philosophy (New York, ny: Oxford U. P., 2005). The editors of The Cambridge Companion to Frege partially... (shrink)

"A valuable collection both for original source material as well as historical formulations of current problems."-- The Review of Metaphysics "Much more than a mere collection of papers . . . a valuable addition to the literature."-- Mathematics of Computation An anthology of fundamental papers on undecidability and unsolvability by major figures in the field, this classic reference opens with Godel's landmark 1931 paper demonstrating that systems of logic cannot admit proofs of all true assertions of arithmetic. Subsequent papers by (...) Godel, Church, Turing, and Post single out the class of recursive functions as computable by finite algorithms. Additional papers by Church, Turing, and Post cover unsolvable problems from the theory of abstract computing machines, mathematical logic, and algebra, and material by Kleene and Post includes initiation of the classification theory of unsolvable problems. Suitable for graduate and undergraduate courses. 1965 ed. (shrink)

A set of propositional connectives is said to be functionally complete if all propositional formulae can be expressed using only connectives from that set. In this paper we give sufficient and necessary conditions for a one-element set of propositional connectives to be functionally complete. These conditions provide a simple and elegant characterization of functionally complete one-element sets of propositional connectives.

Provided here is a characterisation of absolute probability functions for intuitionistic (propositional) logic L, i.e. a set of constraints on the unary functions P from the statements of L to the reals, which insures that (i) if a statement A of L is provable in L, then P(A) = 1 for every P, L's axiomatisation being thus sound in the probabilistic sense, and (ii) if P(A) = 1 for every P, then A is provable in L, L's axiomatisation being (...) thus complete in the probabilistic sense. As there are theorems of classical (propositional) logic that are not intuitionistic ones, there are unary probability functions for intuitionistic logic that are not classical ones. Provided here because of this is a means of singling out the classical probability functions from among the intuitionistic ones. (shrink)

The most difficult problem that Leniewski came across in constructing his system of the foundations of mathematics was the problem of defining definitions, as he used to put it. He solved it to his satisfaction only when he had completed the formalization of his protothetic and ontology. By formalization of a deductive system one ought to understand in this context the statement, as precise and unambiguous as possible, of the conditions an expression has to satisfy if it is added to (...) the system as a new thesis. Now, some protothetical theses, and some ontological ones, included in the respective systems, happen to be definitions. In the present essay I employ Leniewski's method of terminological explanations for the purpose of formalizing ukasiewicz's system of implicational calculus of propositions, which system, without having recourse to quantification, I first extended some time ago into a functionally complete system. This I achieved by allowing for a rule of implicational definitions, which enabled me to define any propositionforming functor for any finite number of propositional arguments. (shrink)

Explicit description of maps definable by formulæ of the second order intuitionistic propositional calculus is given on two classes of linear Heyting algebras—the dense ones and the ones which possess successors. As a consequence, it is shown that over these classes every formula is equivalent to a quantifier free formula in the dense case, and to a formula with quantifiers confined to the applications of the successor in the second case.

(i) It is propositions, not sentences, that are true or false. It is true ‘Dogs bark’ does not make sense. It is true that dogs bark does. (ii) and (iii) Davidson wrong about ‘that’. (iv) The difference between ‘implies’ and ‘if ... then ...’. (v), (vi), (vii) and (viii) Russell, not Quine, right about the subject matter of logic. (ix) The objectual and substitutional interpretations of quantifiers compatible. (x), (xi), (xii), (xiii), (xiv), (xv) and (xvi) Implications for well-known theories of (...) truth; truth correspondence. (xvii), (xviii) and (xix) and (xx) Implications for the principle of bivalence, the law of excluded middle, and the principle of non-contradiction. (xxi) Recapitulation. (xxii) ‘That’ and entailment. (xxiii) Propositions not entities, subsistent or otherwise. Footnotes1 This article was stimulated by some remarks by J. J. C. Smart in criticism of a piece of work (God, Freedom and Immortality, Ashgate, 1999) that he was kind enough to read for me. I am greatly indebted to my friend David Rees for correcting the manuscript, and making some valuable suggestions concerning its content. (shrink)

It is shown that there is no constructive extensional truth-value mapping from the speciesP of all propositions into known constructive structures P.

Recent work in philosophy of language has raised significant problems for the traditional theory of propositions, engendering serious skepticism about its general workability. These problems are, I believe, tied to fundamental misconceptions about how the theory should be developed. The goal of this paper is to show how to develop the traditional theory in a way which solves the problems and puts this skepticism to rest. The problems fall into two groups. The first has to do with reductionism, specifically attempts (...) to reduce propositions to extensional entities-either extensional functions or sets. The second group concerns problems of fine grained content-both traditional 'Cicero'/'Tully' puzzles and recent variations on them which confront scientific essentialism. After characterizing the problems, I outline a non-reductionist approach-the algebraic approach-which avoids the problems associated with reductionism. I then go on to show how the theory can incorporate non-Platonic (as well as Platonic) modes of presentation. When these are implemented nondescriptively, they yield the sort of fine-grained distinctions which have been eluding us. The paper closes by applying the theory to a cluster of remaining puzzles, including a pair of new puzzles facing scientific essentialism. (shrink)