This book has grown out of eight years of close collaboration among its authors. From the very beginning we decided that its content should come out as the result of a truly common effort. That is, we did not "distribute" parts of the text planned to each one of us. On the contrary, we made a point that each single paragraph be the product of a common reflection. Genuine team-work is not as usual in philosophy as it is in other (...) academic disciplines. We think, however, that this is more due to the idiosyncrasy of philosophers than to the nature of their subject. Close collaboration with positive results is as rewarding as anything can be, but it may also prove to be quite difficult to implement. In our case, part of the difficulties came from purely geographic separation. This caused unsuspected delays in coordinating the work. But more than this, as time passed, the accumulation of particular results and ideas outran our ability to fit them into an organic unity. Different styles of exposition, different ways of formalization, different levels of complexity were simultaneously present in a voluminous manuscript that had become completely unmanageable. In particular, a portion of the text had been conceived in the language of category theory and employed ideas of a rather abstract nature, while another part was expounded in the more conventional set-theoretic style, stressing intui tivity and concreteness. (shrink)

The “official” history of connexive logic was written in 2012 by Storrs McCall who argued that connexive logic was founded by ancient logicians like Aristotle, Chrysippus, and Boethius; that it was further developed by medieval logicians like Abelard, Kilwardby, and Paul of Venice; and that it was rediscovered in the 19th and twentieth century by Lewis Carroll, Hugh MacColl, Frank P. Ramsey, and Everett J. Nelson. From 1960 onwards, connexive logic was finally transformed into non-classical calculi which partly concur with (...) systems of relevance logic and paraconsistent logic. In this paper it will be argued that McCall’s historical analysis is fundamentally mistaken since it doesn’t take into account two versions of connexivism. While “humble” connexivism maintains that connexive properties only apply to “normal” antecedents, “hardcore” connexivism insists that they also hold for “abnormal” propositions. It is shown that the overwhelming majority of the forerunners of connexive logic were only “humble” connexivists. Their ideas concerning connexive implication don’t give rise, however, to anything like a non-classical logic. (shrink)

Magnetism in meta-semantics is the view that the meaning of our words is determined in part by their use and in part by the objective naturalness of candidate meanings. This hypothesis is commonly attributed to David Lewis, and has been put to philosophical work by Brian Weatherson, Ted Sider and others. I argue that there is no evidence that Lewis ever endorsed the view, and that his actual account of language reveals good reasons against it.

Dieses Buch enthält in einer historisch-kritischen Edition die Texte, die es in seinem Hauptteil kommentiert: Das Vorwort (1893) zu Gottlob Freges Hauptwerk, den "Grundgesetzen der Arithmetik", in dem er seine fulminante Psychologismus-Kritik vorträgt; die drei von Frege selbst veröffentlichten "Logischen Untersuchungen" (1918-1923), in denen er "die Ernte [s]eines Lebens heimbringen" wollte; und schließlich ein Fragment aus seinem Nachlass, das der Entwurf zu einer vierten LU ist.

The paper takes an expressivistic perspective, i.e., it takes conditionals of all sorts to primarily express conditional beliefs. Therefore it is based on what it takes to be the best account of conditional belief, namely ranking theory. It proposes not to start looking at the bewildering linguistic phenomenology, but first to systematically study the various options of expressing features of conditional belief. Those options by far transcend the Ramsey test and include relevancies of various kinds and in particular the so-called (...) “circumstances are such that” reading, under which also all conditionals representing causal relations can be subsumed. In this way a unifying perspective on the many kinds of conditionals is offered. The final section explains the considerable extent to which truth conditions for conditionals, which may seem lost in the expressivistic or epistemic perspective, may be recovered. (shrink)

The paper builds on the basically Humean idea that A is a cause of B iff A and B both occur, A precedes B, and A raises the metaphysical or epistemic status of B given the obtaining circumstances. It argues that in pursuit of a theory of deterministic causation this ‘status raising’ is best explicated not in regularity or counterfactual terms, but in terms of ranking functions. On this basis, it constructs a rigorous theory of deterministic causation that successfully deals (...) with cases of overdetermination and pre-emption. It finally indicates how the account's profound epistemic relativization induced by ranking theory can be undone. Introduction Variables, propositions, time Induction first Causation Redundant causation Objectivization. (shrink)

Our senses provide us with information about the world, but what exactly do they tell us? I argue that in order to optimally respond to sensory stimulations, an agent’s doxastic space may have an extra, “imaginary” dimension of possibility; perceptual experiences confer certainty on propositions in this dimension. To some extent, the resulting picture vindicates the old-fashioned empiricist idea that all empirical knowledge is based on a solid foundation of sense-datum propositions, but it avoids most of the problems traditionally associated (...) with that idea. The proposal might also explain why experiences appear to have a non-physical phenomenal character, even if the world is entirely physical. (shrink)

Concentrating upon applications that are most relevant to modern physics, this valuable book surveys variational principles and examines their relationship to dynamics and quantum theory. Stressing the history and theory of these mathematical concepts rather than the mechanics, the authors provide many insights into the development of quantum mechanics and present much hard-to-find material in a remarkably lucid, compact form. After summarizing the historical background from Pythagoras to Francis Bacon, Professors Yourgrau and Mandelstram cover Fermat's principle of least time, the (...) principle of least action of Maupertuis, development of this principle by Euler and Lagrange, and the equations of Lagrange and Hamilton. Equipped by this thorough preparation to treat variational principles in general, they proceed to derive Hamilton's principle, the Hamilton-Jacobi equation, and Hamilton's canonical equations. An investigation of electrodynamics in Hamiltonian form covers next, followed by a resume of variational principles in classical dynamics. The authors then launch into an analysis of their most significant topics: the relation between variational principles and wave mechanics, and the principles of Feynman and Schwinger in quantum mechanics. Two concluding chapters extend the discussion to hydrodynamics and natural philosophy. Professional physicists, mathematicians, and advanced students with a strong mathematical background will find this stimulating volume invaluable reading. Extremely popular in its hardcover edition, this volume will find even wider appreciation in its first fine inexpensive paperbound edition. (shrink)

Eine Einfiihrung in die epistemische Logik wurde schon vor unge fahr zwei Jahrzehnten durch Jaakko Hintikka geschrieben, und auf sein "Knowledge and Belief" nimmt das vorliegende Buch nicht nur durch den Titel "Glauben, Wissen und Wahrscheinlichkeit" Bezug. Es diirfte deshalb wohl angebracht sein, wenn der Autor eines Buches, das so deutlich die Nachfolgeschaft eines anderen beansprucht, sich dafiir rechtfertigt und erklart, worin sich sein Werk von dem des Vorgangers unterscheidet. Ein wichtiger Punkt, in dem die zweite iiber die erste Einleitung (...) in die epistemische Logik hinausgeht, wird schon durch die Titel erganzung "... und Wahrscheinlichkeit" signalisiert. Wahrend Hin tikkas erkenntnistheoretische Untersuchungen sich fast ausschlieB lich auf die Bestimmung einer Wissenslogik ("episteme") konzen trierten, werden hier unter Bezugnahme auf die Theorie subjektiver Wahrscheinlichkeit zusatzlich diverse Glaubenslogiken ("doxa") ent wickelt. Insbesondere wird ein Begriff "schwachen" Glaubens im Sinne des Fiir-wahrscheinlich-Haltens vom "starken" Glaubensbe griff im Sinne festester Oberzeugungen abgegrenzt, eine Unterschei dung, die im angelsachsischen Sprachraum bei der Diskussion der Logik von "belief" straflich vernachlassigt wurde. Die genaue Aus arbeitung dieses Unterschieds, die exakte semantische Charakteri sierung der entsprechenden doxastischen Modaloperatoren, und die Suche nach vollstandigen Axiomatisierungen korrespondierender Logiken fiihrte dabei in (mathematisches) Neuland: zur Theorie klassifikatorischer Wahrscheinlichkeit. Diese erste wesentliche Wei terentwicklung von "Knowledge and Belief" konnte man durch die Formel beschreiben: von rein epistemischer Logik hin zu epistemi scher und doxastischer Logik. (shrink)

In addition to discussing some philosophical accounts of common sense, this article considers several ways in which common sense can be altered or disturbed in psychopathology. Common sense can be defined as practical understanding, capacity to see and take things in their right light, sound judgment, or ordinary mental capacity. The philosopher Vico described it as the ability to distinguish the probable from the improbable. Goethe understood common sense as an "organ" that is formed in communication for the purpose of (...) communication. Common sense is rooted in the intersubjective constitution of the life-world. Obsessive-compulsive patients show relatively mild disturbances of common sense. Patients with major affective psychoses, in their premorbid personality structure, are overly attached to common sense. In schizophrenia, however, there seems to be a true abdication of common sense involving a loss of "natural self-evidence." Even in premorbid states, such persons often lose both the sense of tact and the ability to "take things in their right light." Although logic, and the ability to engage in theoretical discussion, may be preserved, there is a loss of interpretive skills and the "faculty of judgment"; this results in an inability to cope with everyday practical and social activity. There is also a characteristic sense of perplexity, a sense of amazement before that which would normally seem self-evident and a frequent tendency to reflect upon the conditions of possibility of existence that otherwise remain concealed. The author suggests that the fragility of common sense should not be seen as a mere deficiency state. Rather, it derives from a basic vulnerability inherent in the very structure of being human. (Abstract written by special issue editor: L.A.S.). (shrink)

The central idea of this essay is that philosophical thinking revolves around aporetic clusters, i.e., sets of individually plausible, but collectively inconsistent propositions. The task of philosophy is to dissolve such clusters, either by showing that the propositions in question, contrary to first impression, are compatible with each other, or by showing that it is permissible to abandon at least one of the propositions involved. This view of philosophical problems not only provides a very good description of well-understood philosophizing, but (...) is also better suited than others to explain some seemingly strange characteristics of philosophy, most notably its armchair character, the large variety of incommensurable doctrines by which it is characterized, and its concern with its own history. (shrink)

Rational agents are supposed to maximize expected utility. But what are the options from which they choose? I outline some constraints on an adequate representation of an agent’s options. The options should, for example, contain no information of which the agent is unsure. But they should be sufficiently rich to distinguish all available acts from one another. These demands often come into conflict, so that there seems to be no adequate representation of the options at all. After reviewing existing proposals (...) for how to construe decision-theoretic options and finding them all wanting, I suggest that our model of rational agents should include a special domain of ‘virtual’ option propositions to serve as formal objects of deliberation and choice. (shrink)

The paper displays the similarity between the theory of probabilistic causation developed by Glymour et al. since 1983 and mine developed since 1976: the core of both is that causal graphs are Bayesian nets. The similarity extends to the treatment of actions or interventions in the two theories. But there is also a crucial difference. Glymour et al. take causal dependencies as primitive and argue them to behave like Bayesian nets under wide circumstances. By contrast, I argue the behavior of (...) Bayesian nets to be ultimately the defining characteristic of causal dependence. (shrink)

The paper argues that Gareth Evans’ argument for transparent self-knowledge is based on a conflation of doxastic transparency with ascriptive transparency. Doxastic transparency means that belief about one’s own doxastic state, e.g., the belief that one thinks that it will rain, can be warranted by ordinary empirical observation, e.g., of the weather. In contrast, ascriptive transparency says that self-ascriptions of belief, e.g., “I believe it will rain”, can be warranted by such observation. We first show that the thesis of doxastic (...) transparency is ill-motivated and then offer a non-epistemic interpretation of ascriptive transparency by reference to the theory of explicit expressive acts: “I think it will rain” requires attendance to the weather because the utterance expresses a belief about the weather, not about ourselves. This will allow us to avoid what is often called “the puzzle of transparent self-knowledge” while remaining faithful to Evans’ linguistic observations. (shrink)

One of the main controversies of the Logic Schools of the 12th century centered on the question: What follows from the impossible? In this paper arguments for two diametrically opposed positions are examined. The author of the ‘Avranches Text’ who probably belonged to the school of the Parvipontani defended the view that from an impossible proposition everything follows (‘Ex impossibili quodlibet’). In particular he developed a proof to show that by means of so-called ‘disjunctive syllogism’ any arbitrary proposition B can (...) be logically derived from a pair of contradictory propositions A and Not-A. The author of the Ars Meliduna instead argued that nothing follows from an impossible proposition (‘ex falso nihil sequitur’). This view is supported by various counterexamples which aimed to show that the admission of impossible premises would give rise to inconsistent conclusions. Upon closer analysis these inconsistencies do not, however, have the formal structure of a real contradiction like A and Not-A, but rather the structure of two rivalling conditionals like ‘If B then A’ and ‘If B then Not-A’. Hence these counterexamples rather have to be considered as refutations of the basic principles of ‘connexive logic’. (shrink)

The paper analyzes the nature and scope of Moore’s paradox, articulates the desiderata of a successful solution and claims that psychological expressivism best meets these desiderata. After a brief discussion of prominent responses to Moore’s paradox, the paper offers a solution based on a theory of expressive acts: a Moorean utterance is absurd because the speaker expresses mental states with conflicting contents in commissive versions of the paradox and conflicting states of mind in omissive versions. The paper presents a theory (...) of expressivism for self-ascriptions of mental states. In addition, it introduces the idea of expressive denegation—the speaker’s expressing the absence of a mental state—as an analysis of negative self-ascriptions of mental states. Some of the consequences of expressivism for avowals are explored. (shrink)

_ Source: _Page Count 16 This paper deals with an apparent tension in Wittgenstein’s _Philosophical Investigations_: Wittgenstein holds an expressivist position with regard to avowals, but also claims that the _doxastic_ avowal “I believe that p” is a “hesitant assertion” of p. It is argued that the tension is apparent only and that Wittgenstein’s expressivism in fact justifies and explains his views on “I believe”: avowals typically are _explicit expressives_ and usually implicate the corresponding illocutionary acts. The hesitant assertion of (...) p is the result of an implicature of the explicit expressive “I believe that p”. The paper also addresses the ambiguity of avowals and the possibility of thereby undermining the Frege–Geach objection to psychological expressivism. (shrink)

The numerous modal systems between S4 and S5 are investigated from an epistemological point of view by interpreting necessity either as knowledge or as (strong) belief. It is shown that-granted some assumptions about epistemic logic for which the author has argued elsewhere-the system S4.4 may be interpreted as the logic of true belief, while S4.3.2 and S4.2 may be taken to represent epistemic logic systems for individuals who accept the scheme knowledge = true belief only for certain special instances. There (...) is strong evidence in favor of the assumption that S4.2 is the logic of knowledge. (shrink)

Buridan endorsed the principles that any impossible, and a fortiori any self-contradictory, proposition entails each proposition. These principles are usually referred to as ‘Ex impossibili quodlibet’ (EIQ) and ‘Ex contradictione quodlibet’ (ECQ). Buridan further considered the instance ECCQ according to which any proposition follows from the conjunction of two contradictory propositions. Buridan showed how ECCQ can be proven by means the usual laws of conjunction and disjunction. Furthermore, he discovered that EIQ can be derived from ECCQ by means of the (...) principle that if a conclusion q follows from two premises, one of which is necessary, then q follows from the other premise alone. Buridan thought that this principle would be provable; but his proof turned out to be circular since it presupposed EIQ. Nevertheless, EIQ is validated by the definition of a ‘bona consequentia’. Somewhat more exactly, according to Buridan one may distinguish between inferences which are formally valid, ‘materially’ valid, and valid ‘as of now’. It is shown that formally valid inferences satisfy ECQ while ‘materially’ valid inferences satisfy EIQ. Furthermore, inferences which are valid ‘as of now’ satisfy the principle ‘Ex falso quodlibet’ saying that any false proposition ‘as of now’ entails every proposition. (shrink)

It has recently been argued that some cases of naked statistical evidence license a high credence, but not an outright belief. If this is correct, there cannot be an unconditional bridge principle from credence to outright belief. We show that at least one prominent putative counterexample to such a bridge principle is based on a mistake, by demonstrating that the statistical evidence falls short not only of licensing rational belief, but also of justifying a high credence.

First published in 1986 and reprinted in 2010 in the Routledge Revivals series, this book presents the first detailed confrontation between the Austrian school of economics and Austrian philosophy, especially the philosophy of the Brentano school. It contains a study of the roots of Austrian economics in the liberal political theory of the nineteenth-century Hapsburg empire, and a study of the relations between the general theory of value underlying Austrian economics and the new economic approach to human behaviour propounded by (...) Gary Becker and others in Chicago. In addition, it considers the connections between Austrian methodology and contemporary debates in the philosophy of the social sciences. (shrink)

The founder of modern logic and grandfather of analytic philosophy was 70 years old when he published his paper 'Der Gedanke' (The Thought ) in 1918. This essay contains some of Gottlob Frege's deepest and most provocative reflections on the concept of truth, and it will play a prominent role in my lectures. The plan for my lectures is as follows. What is it that is (primarily) true or false? 'Thoughts', is Frege's answer. In §1, I shall explain and defend (...) this answer. In §2, I shall briefly consider his enthymematic argument for the conclusion that the word 'true' resists any attempt at defining it. In §3, I shall discuss his thesis that the thought that things are thus and so is identical with the thought that it is true that things are thus and so. The reasons we are offered for this thesis will be found wanting. In §4, I shall comment extensively on Frege's claim that, in a non-formal language like the one I am currently trying to speak, we can say whatever we want to say without ever using the word 'true' or any of its synonyms. I will reject the propositional-redundancy claim, endorse the assertive-redundancy claim and deny the connection Frege ascribes to them. In his classic 1892 paper 'Über Sinn und Bedeutung' (On Sense and Signification) Frege argues that truth-values are objects. In §5, I shall scrutinize his argument. In §6, I will show that in Frege's ideography (Begriffsschrift) truth, far from being redundant, is omnipresent. The final §7 is again on truth-bearers, this time as a topic in the theory of intentionality and in metaphysics. In the course of discussing Frege's views on the objecthood, the objectivity of thoughts and the timelessness of truth(s), I will plead for a somewhat mitigated Platonism. (shrink)

The paper is motivated by the need of accounting for the practical syllogism as a piece of defeasible reasoning. To meet the need, the paper first refers to ranking theory as an account of defeasible descriptive reasoning. It then argues that two kinds of ought need to be distinguished, purely normative and fact-regarding obligations. It continues arguing that both kinds of ought can be iteratively revised and should hence be represented by ranking functions, too, just as iteratively revisable beliefs. Its (...) central proposal will then be that the fact-regarding normative ranking function must be conceived as the sum of a purely normative ranking function and an epistemic ranking function. The distinctions defends this proposal with a comparative discussion of some critical examples and some other distinctions made in the literature. It gives a more rigorous justification of this proposal. Finally, it starts developing the logic of purely normative and of fact-regarding normative defeasible reasoning, points to the difficulties of completing the logic of the fact-regarding side, but reaches the initial aim of accounting for the defeasible nature of the practical syllogism. (shrink)

This article aims to show that Williamson's anti-luminosity argument does not succeed if we presuppose a constitutive connection between the phenomenal and the doxastic. In contrast to other luminists, however, my strategy is not to critically focus on the refined safety condition in terms of degrees of confidence that anti-luminists typically use in this context. Instead, I will argue that, given a certain conception of what Chalmers calls ‘direct phenomenal concepts,’ luminosity is guaranteed even if the refined safety condition in (...) terms of degrees of confidence is taken for granted. (shrink)

This paper attempts to develop a projectivistic understanding of chance or objective probability or partial determination. It does so by critically examining David Lewis’ philosophy of probability and his defense of Humean Supervenience, building thereupon the constructive projectivistic alternative, which will basically be a suitable reinterpretation of de Finetti’s position. Any treatment of the topic must show how it extends to natural necessity or deterministic laws or full determination in perfect parallel. The paper indicates at the end how this demand (...) can be met. (shrink)

Abelard: Logic This article describes and reconstructs Peter Abelard’s logic of the twelfth century. Much of what he regarded as logic is now classified as ontology or philosophical semantics. The article concentrates on his treatment of the relation of consequence. Abelard’s most important logical innovations consist of two points: The distinction between two kinds of … Continue reading Abelard: Logic →.

This paper scrutinizes Everett Nelson's conception of consistency by comparing it with the “standard” account of C. I. Lewis. This conflict surprisingly resembles a related controversy between the ancient logicians Chrysippus and Diodorus. Nelson's intuitions behind his peculiar conception of consistency are analysed and certain features of his logical system are critically examined. In particular, his objections against the law of the transitivity of implication and against the laws of conjunction and disjunction have to be discussed. Although Nelson's considerations contain (...) interesting ideas in favour of a relevantist conception of logic, they fail to convincingly support the hardcore connexive thesis that even a selfcontradictory proposition doesn't entail its own negation. (shrink)

As the paper explains, it is crucial to epistemology in general and to the theory of causation in particular to investigate the properties of conditional independence as completely as possible. The paper summarizes the most important results concerning conditional independence with respect to two important representations of epistemic states, namely (strictly positive) probability measures and natural conditional (or disbelief or ranking) functions. It finally adds some new observations.

Analogical reasoning addresses the question how evidence from various phenomena can be combined and made relevant for theory development and prediction. In the first part of my contribution, I review some influential accounts of analogical reasoning, both historical and contemporary, focusing in particular on Keynes, Carnap, Hesse, and more recently Bartha. In the second part, I sketch a general framework. To this purpose, a distinction between a predictive and a conceptual type of analogical reasoning is introduced. I then take up (...) a common intuition according to which analogical inferences hold if the differences between source and target concern only irrelevant circumstances. I attempt to make this idea more precise by addressing possible objections and in particular by specifying a notion of causal irrelevance based on difference making in homogeneous contexts. (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)

Since their formulation by Keith DeRose (1992), the so-called bank cases have played a major role in the discussion about whether knowledge depends on practical factors. According to the proponents of pragmatic encroachment, the proper conclusion to be drawn from the bank cases and similar examples is that knowledge of a proposition _p_ does not supervene on one’s evidence for or against _p_. In my view, this conclusion is ill-founded. The reason is that the bank cases and similar examples suffer (...) from an ambiguity concerning the known proposition — an ambiguity that has so far been overlooked. When this ambiguity is made explicit, it becomes clear that the conclusion does not follow. (shrink)

The core idea of the ontological proof is to show that the concept of existence is somehow contained in the concept of God, and that therefore God’s existence can be logically derived—without any further assumptions about the external world—from the very idea, or definition, of God. Now, G.W. Leibniz has argued repeatedly that the traditional versions of the ontological proof are not fully conclusive, because they rest on the tacit assumption that the concept of God is possible, i.e. free from (...) contradiction. A complete proof will rather have to consist of two parts. First, a proof of premiseGod is possible. Second, a demonstration of the “remarkable proposition”If God is possible, then God exists. The present contribution investigates an interesting paper in which Leibniz tries to prove proposition. It will be argued that the underlying idea of God as a necessary being has to be interpreted with the help of a distinguished predicate letter ‘E’ as follows:\\). Proposition which Leibniz considered as “the best fruit of the entire logic” can then be formalized as follows:\) \rightarrow \, E)\). At first sight, Leibniz’s proof appears to be formally correct; but a closer examination reveals an ambiguity in his use of the modal notions. According to, the possibility of the necessary being has to be understood in the sense of something which possibly exists. However, in other places of his proof, Leibniz interprets the assumption that the necessary being is impossible in the diverging sense of something which involves a contradiction. Furthermore, Leibniz believes that an »impossible thing«, y, is such that contradictory propositions like \\) and \\) might both be true of y. It will be argued that the latter assumption is incompatible with Leibniz’s general views about logic and that the crucial proof is better reinterpreted as dealing with the necessity, possibility, and impossibility of concepts rather than of objects. In this case, the counterpart of turns out to be a theorem of Leibniz’s second order logic of concepts; but in order to obtain a full demonstration of the existence of God, the counterpart of, i.e. the self-consistency of the concept of a necessary being, remains to be proven. (shrink)

Buridan endorses the basic idea that q follows from p iff it is impossible that p is true but q is false. Since he also accepts the law that, if p is impossible, the conjunction (p ∧ q) must be impossible, he comes to regard the principle ‘Ex impossibili quodlibet’ (EIQ) as basically correct. However, his logic is based on a ‘nominalist’ view according to which propositions are tokens of spoken, written or thought language existing in space of time, and (...) the truth of such a proposition presupposes that it exists. This conception prompted Buridan to modify the definition of ‘consequence’, but none of his attempts was fully successful. Yet, a large part of his theory of consequences is based on the usual account of necessary truth-conservation. As regards principle EIQ, Buridan distinguishes two variants of impossibility. Proposition p is possible iff the state of affairs as described by p is possible; this doesn’t guarantee, however, that p is ‘possibly true’. E.g. ‘No proposition is negative’ is considered by Buridan as describing a possible state of affairs, but this proposition is not possibly true, because in order to be true, it would have to exist, and as soon as it comes into existence, it becomes false. Accordingly, EIQ requires that the antecedent p is really impossible and not only impossibly true. (shrink)

The paper attempts to rationalize cooperation in the one-shot prisoners' dilemma (PD). It starts by introducing (and preliminarily investigating) a new kind of equilibrium (differing from Aumann's correlated equilibria) according to which the players' actions may be correlated (sect. 2). In PD the Pareto-optimal among these equilibria is joint cooperation. Since these equilibria seem to contradict causal preconceptions, the paper continues with a standard analysis of the causal structure of decision situations (sect. 3). The analysis then raises to a reflexive (...) point of view according to which the agent integrates his own present and future decision situations into the causal picture of his situation (sect. 4). This reflexive structure is first applied to the toxin puzzle and then to Newcomb's problem, showing a way to rationalize drinking the toxin and taking only one box with-out assuming causal mystery (sect. 5). The latter result is finally extended to a rationalization of cooperation in PD (sect. 6). (shrink)

There is a tacit assumption that interpretation comes naturally, that human beings live by constantly interpreting. In this sense, we might even rephrase Descartes by saying: We interpret, therefore we are. While such a basic human disposition makes interpretation appear to come naturally, the forms it takes, however, do not. In this work, Iser offers a fresh approach by formulating an "anatomy of interpretation" through which we can understand the act of interpretation in its many different manifestations. For Iser, there (...) are several different genres of interpretation, all of which are acts of translation designed to transpose something into something else. Perhaps the most obvious example of interpretation involves canonical texts, such as the Rabbinical exegesis of the Torah or Samuel Johnson's reading of Shakespeare. But what happens when the matter that one seeks to interpret consists not of a text but of a welter of fragments, as in the study of history, or when something is hidden, as in the practice of psychoanalysis, or is as complex as a culture or system? Iser details how, in each of these cases, the space that is opened up by interpretation is negotiated in a different way, thus concluding that interpretation always depends on what it seeks to translate. For students of philosophy, literary and critical theory, anthropology, and cultural history, Iser's elucidation of the mechanics by which we translate and understand, as well as his assessment of the anthropological roots of our drive to make meaning, will undoubtedly serve as a revelation. (shrink)

This paper deals with Hans Reichenbach's common cause principle. It was propounded by him in, and has been developed and widely applied by Wesley Salmon, e.g. in and. Thus, it has become one of the focal points of the continuing discussion of causation. The paper addresses five questions. Section 1 asks: What does the principle say? And section 2 asks: What is its philosophical significance? The most important question, of course, is this: Is the principle true? To answer that question, (...) however, one must first consider how one might one argue about it at all. One can do so by way of examples, the subject of section 3, or more theoretically, which is the goal of section 4. Based on an explication of probabilistic causation proposed by me in,, and, section 4 shows that a variant of the principle is provable within a classical framework. The question naturally arises whether the proved variant is adequate, or too weak. This is pursued in section 5. My main conclusion will be that some version of Reichenbach's principle is provably true, and others may be. This may seem overly ambitious, but it is not. The paper does not make any progress on essential worries about the common cause principle arising in the quantum domain; it only establishes more rigorously what has been thought to be plausible at least within a classical framework. (shrink)