This book aims to develop certain aspects of Gottlob Frege’s theory of meaning, especially those relevant to intensional logic. It offers a new interpretation of the nature of senses, and attempts to devise a logical calculus for the theory of sense and reference that captures as closely as possible the views of the historical Frege. (The approach is contrasted with the less historically-minded Logic of Sense and Denotation of Alonzo Church.) Comparisons of Frege’s theory with those of Russell and others (...) are given. It is in the end shown that developing Frege’s theory in these ways reveals serious problems hitherto largely unnoticed, including those possibly rendering a Fregean intensional logic inconsistent even if his naïve class theory is excluded. (shrink)

This is identical with the first edition (see 21: 2716) except for the addition of a Supplement containing 5 previously published articles and the bringing of the bibliography (now 73 items) up to date. The 5 added articles present clarifications or modifications of views expressed in the first edition. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Direct reference theory faces serious prima facie counterexamples which must be explained away (e.g., that it is possible to know a priori that Hesperus = Phosphorus). This is done by means of various forms of pragmatic explanation. But when those explanations that provisionally succeed are generalized to deal with analogous prima facie counterexamples concerning the identity of propositions, a fatal dilemma results. Either identity must be treated as a four-place relation (contradicting what just about everyone, including direct reference theorists, takes (...) to be essential to identity). Or direct reference theorists must incorporate a view that was rejected in pretty much our first lesson about identity—namely, that Hesperus at twilight is not identical to Hesperus at dawn. One way of the other, the direct reference theory is thus inconsistent with basic principles concerning the logic of identity, which nearly everyone, including direct reference theorists, take as starting points. (shrink)

Chapter One: Constructions. Entities, constructions, and functions When one travels from Los Angeles to New York, going, say, by way of St. Louis, Chicago, ...

Since the mid-twentieth century, the concept of the Turing machine has dominated thought about effective procedures. This paper presents an alternative to Turing's analysis; it unifies, refines, and extends my earlier work on this topic. I show that Turing machines cannot live up to their billing as paragons of effective procedure; at best, they may be said to provide us with mere procedure schemas. I argue that the concept of an effective procedure crucially depends upon distinguishing procedures as definite courses (...) of action(- types) from the particular courses of action(-tokens) that actually instantiate them and the causal processes and/or interpretations that ultimately make them effective. On my analysis, effectiveness is not just a matter of logical form; `content' matters. The analysis I provide has the advantage of applying to ordinary, everyday procedures such as recipes and methods, as well as the more refined procedures of mathematics and computer science. It also has the virtue of making better sense of the physical possibilities for hypercomputation than the received view and its extensions, e.g. Turing's o-machines, accelerating machines. (shrink)

§0. Alonzo Church's contributions to philosophy and to that most philosophical part of logic, intensional logic, are impressive indeed. He wrote relatively few papers actually devoted to specifically philosophical issues, as distinguished from related technical work in logic. Many of his contributions appear in reviews for The Journal of Symbolic Logic, and it can hardly be maintained that one finds there a “philosophical system”. But there occur a clearly articulated and powerful methodology, terse arguments, often of “crushing cogency”, and philosophical (...) observations of the first importance.Many of the less formal philosophical contributions center around questions concerning meaning, but there are important clarifications and insights into matters of the epistemology and ontology of the sciences, especially the formal sciences.1.1. The logistic method. Church's writings on philosophical matters exhibit an unwavering commitment to what he called the “logistic method”. The term did not catch on and now one would just speak of “formalization”. The use of these ideas is now so common and familiar among logicians and logically-oriented philosophers that they are simply taken for granted. But they deserve to be celebrated and re-emphasized, for there are philosophers who seriously underestimate and even consciously reject these techniques. (shrink)

Expressions in a language, whether words, phrases, or sentences, have meanings. So it seems reasonable to suppose that there are meanings that expressions have. Of course, it is fashionable in some philosophical circles to deny this.

"This book is valuable as expounding in full a theory of meaning that has its roots in the work of Frege and has been of the widest influence.

The classical theory of semantic information (ESI), as formulated by Bar-Hillel and Carnap in 1952, does not give a satisfactory account of the problem of what information, if any, analytically and/or logically true sentences have to offer. According to ESI, analytically true sentences lack informational content, and any two analytically equivalent sentences convey the same piece of information. This problem is connected with Cohen and Nagel's paradox of inference: Since the conclusion of a valid argument is contained in the premises, (...) it fails to provide any novel information. Again, ESI does not give a satisfactory account of the paradox. In this paper I propose a solution based on the distinction between empirical information and analytic information. Declarative sentences are informative due to their meanings. I construe meanings as structured hyperintensions, modelled in Transparent Intensional Logic as so-called constructions. These are abstract, algorithmically structured procedures whose constituents are sub-procedures. My main thesis is that constructions are the vehicles of information. Hence, although analytically true sentences provide no empirical information about the state of the world, they convey analytic information, in the shape of constructions prescribing how to arrive at the truths in question. Moreover, even though analytically equivalent sentences have equal empirical content, their analytic content may be different. Finally, though the empirical content of the conclusion of a valid argument is contained in the premises, its analytic content may be different from the analytic content of the premises and thus convey a new piece of information. (shrink)

This paper is about the cluster of issues that orbit a well-known thesis of Quine’s, as it applies to attitude ascriptions.

This book is in the Studies in Philosophy: Outstanding Dissertations series. Its central theme is that Frege’s concept-notation is inadequate because it does not formalize his semantic theory after the introduction of the sense-reference distinction in 1891. This failing, according to Klement, opens Frege up to a number of philosophical and logical challenges that can be met only by completing the project of showing “how Frege’s mature semantic views would be incorporated into his mature logical system”, a project which, Klement (...) plausibly argues, Frege would have endorsed. This involves: allowing the concept-notation to represent explicitly what is expressed in natural language with indirect constructions such as “said that...” or “believes that... ”; allowing principles to be formulated over this notion which capture inferences involving indirect constructions such as: The Morning Star is a planet, Gottlob believes the Morning Star is a planet, so, Gottlob believes something true; being able to respond to certain objections to Frege’s views, some first bruited by Russell and in later correspondence, others involving the identity conditions on intensional entities and “quantifying in” ; making the concept-notation reflect Frege’s ontology; and evaluating the consistency of Frege’s ontology. The chapters of this book are devoted to fulfilling this project “based upon a careful reading of Frege’s own works”, and their contents are mostly self-explanatory. Chapter 2 sets out the formal apparatus of the Grundgeseze, even the bits Frege left out. Chapter 3 is the most philosophical. Senses are construed as interpersonally accessible information uniquely true of the references they determine—senses are objects and functions in the “third realm.” Singular terms are associated with an impossibly rich hierarchy of senses as objects. Functors, including predicates, are associated with senses as functions. Sentences are associated with thoughts as objects, composed of constituent sense-functions, and in many cases, also sense-objects. Robust compositionality at the level of sense raises the question of the nature of the relation between constituents and the whole—is it functional, or not? Compositionality potentially conflicts with a number of other claims, and Klement’s conclusion is reasonable: “the context principle, the priority thesis, and the possibility of there existing multiple decompositions for the same Gedanke, do not pose any great difficulty for the compositionality principle or the understanding of Gedanke as having determinate inner structures”. Chapter 4 sets out Church’s original system and investigates reformulations suggested by Church himself, Kaplan, and others. Chapter 5 presents Klement’s formalization of an intensional logic of sense and reference, based on the results of chapters 2 and 4, and sufficient for indirect speech and quantifying-in, but containing a contradiction. Chapter 6 takes up arguments of early Russell, Searle, and Bergmann. Chapter 7 addresses strategies for repairing the inconsistencies of chapter 5, but in a Fregean spirit: dropping some realms of entities, restricting their number, or modifying our conception of their nature. (shrink)