The aim of the article is to analyze the situation of contemporary logic with reference to the issue concerning connections between the pluralism of logical systems and relativism in logic. Accordingly, I seek answers to the following questions: Can the plurality of logic, more specifically, a large number and variety of systems constructed by logicians, be justified in a rational way? Does pluralism in logic imply the thesis of relativism? Is logical relativism in the contemporary philosophy of logic just a (...) superstition or is it a duly substantiated view? (shrink)
Quine’s classical classic interpretation succinctly characterized characterizes Carnap’s Aufbau as an attempt “to account for the external world as a logical construct of sense-data....” Consequently, “Russell” was characterized as the most important influence on the Aufbau. Those times have passed. Formulating a comprehensive and balanced interpretation of the Aufbau has turned out to be a difficult task and one that must take into account several disjointed sources. My thesis is that the core of the Aufbau rested on a problem that (...) had haunted German philosophy since the end of the 19th century. In terms fashionable at the time, this problem may be expressed as the polarity between Leben and Geist that characterized German philosophy during the years of the Weimar Republic. At that time, many philosophers, including Cassirer, Rickert and Vaihinger, were engaged in overcoming this polarity. As I will show, Carnap’s Aufbau joined the ranks of these projects. This suggests that Lebensphilosophie and Rickert’s System der Philosophie exerted a strong influence on Carnap’s projects, an influence that is particularly conspicuous in his unpublished manuscript Vom Chaos zur Wirklichkeit. Carnap himself asserted that this manuscript could be considered “the germ of the constitution theory” of the Aufbau. Reading Chaos also reveals another strong but neglected influence on the Aufbau, namely a specific version of neutral monism put forward by the philosopher and psychologist Theodor Ziehen before World War I. Ziehen’s work contributed much to the invention of the constitutional method of quasi-analysis. -/-. (shrink)
Carnap’s Ideal of Explication and Naturalism is the second book on Rudolf Carnap’s philosophy edited by Pierre Wagner for Palgrave Macmillan’s series The History of Analytic Philosophy. The collection of essays is important for several reasons both for philosophers and historians of philosophy, but some parts of it will also be valuable to anyone interested in general scientific methodologies. I shall first survey the theme in order to locate the collection within the recent philosophical discussion then I will consider the (...) volume itself. (shrink)
Testabilite et signification est un classique de la philosophie des sciences dont aucune traduction n'avait jusqu'alors ete offerte au public francophone. L'auteur y expose sa celebre analyse des termes dispositionnels en montrant quelles difficultes souleve leur definition. Carnap livre egalement ici ses reflexions sur la nature de l'empirisme et sur le rapport du langage a la philosophie, offrant ainsi, dans ce texte, l'une des premieres expositions du probleme contemporain de la confirmation, soigneusement distinguee de la verification et du test. Historiquement, (...) l'ouvrage est aussi marque par un mouvement de transition: celle de la langue allemande a l'anglais d'adoption, celle de l'emigration de son auteur, de Prague a Chicago, celle d'une pensee d'origine europeenne venue, sur le chemin de l'exil, a la rencontre de la philosophie americaine. (shrink)
In this paper, Carnap's modal logic C is reconstructed. It is shown that the Carnapian approach enables us to create some epistemic logics in a relatively straightforward way. These epistemic modifications of C are axiomatized and one of them is compared with intuitionistic logic. At the end of the paper, some connections between this epistemic logic and Medvedev's logic of finite problems and inquisitive semantics are shortly discussed.
The paper reconstructs the three main stages in the development of Carnap’s semantics in the years 1935–1947. It starts with Carnap’s approach to metalogic in his Zirkelprotokolle (1931) and his Logische Syntax der Sprache (1934) from the point of view of one-level approach to the relation between metalanguage and its object-language. It then analyzes Tarski’s turn to semantics in his paper presented at the Paris conference in September 1935, as well as the implications of his view for Carnap’s approach to (...) semantics from 1935 until 1943. Finally, it analyzes Church’s rediscovery of Frege and its impact on Carnap’s shift to the extension/intension distinction in his semantics in the years 1943–1947. (shrink)
A basic system of inductive logic; An axiomatic foundation for the logic of inductive generalization; A survey of inductive systems; On the condition of partial exchangeability; Representation theorems of the de finetti type; De finetti's generalizations of excahngeability; The structure of probabilities defined on first-order languages; A subjectivit's guide to objective chance.
Peter Achinstein gives in his papers  and  interesting analyses of some problems of inductive logic and of some approaches I have proposed. I shall discuss here some of these problems in order to clarify my present position. My comments will mainly concern the variety of instances, and only briefly the analogy influence, and the inductive methods for a coordinate language.
APA PsycNET abstract: This is the first volume of a two-volume work on Probability and Induction. Because the writer holds that probability logic is identical with inductive logic, this work is devoted to philosophical problems concerning the nature of probability and inductive reasoning. The author rejects a statistical frequency basis for probability in favor of a logical relation between two statements or propositions. Probability "is the degree of confirmation of a hypothesis (or conclusion) on the basis of some given evidence (...) (or premises)." Furthermore, all principles and theorems of inductive logic are analytic, and the entire system is to be constructed by means of symbolic logic and semantic methods. This means that the author confines himself to the formalistic procedures of word and symbol systems. The resulting sentence or language structures are presumed to separate off logic from all subjectivist or psychological elements. Despite the abstractionism, the claim is made that if an inductive probability system of logic can be constructed it will have its practical application in mathematical statistics, and in various sciences. 16-page bibliography. (PsycINFO Database Record (c) 2016 APA, all rights reserved). (shrink)
Among the various meanings in which the word ‘probability’ is used in everyday language, in the discussion of scientists, and in the theories of probability, there are especially two which must be clearly distinguished. We shall use for them the terms ‘probability1’ and ‘probability2'. Probability1 is a logical concept, a certain logical relation between two sentences ; it is the same as the concept of degree of confirmation. I shall write briefly “c” for “degree of confirmation,” and “c” for “the (...) degree of confirmation of the hypothesis h on the evidence e“; the evidence is usually a report on the results of our observations. On the other hand, probability2 is an empirical concept; it is the relative frequency in the long run of one property with respect to another. The controversy between the so-called logical conception of probability, as represented e.g. by Keynes, and Jeffreys, and others, and the frequency conception, maintained e.g. by v. Mises and Reichenbach, seems to me futile. These two theories deal with two different probability concepts which are both of great importance for science. Therefore, the theories are not incompatible, but rather supplement each other. (shrink)