Patrick Suppes'' set-theoretical approach to the analysis of theories, and Joseph D. Sneed''s metatheory are briefly outlined. The notions of observation, illusion and hallucination are reconstructed according to these approaches. It is argued that the terms perception and truth are theoretical with respect to observation but nontheoretical with respect to illusion and hallucination. Hallucination is construed as a special kind of illusion.

Patrick Suppes' set-theoretical approach to the analysis of theories, and Joseph D. Sneed's metatheory are briefly outlined. The notions of observation, illusion and hallucination are reconstructed according to these approaches. It is argued that the terms ‘perception’ and ‘truth’ are theoretical with respect to observation but nontheoretical with respect to illusion and hallucination. Hallucination is construed as a special kind of illusion.

In this article I give an overview of some recent work in philosophy of science dedicated to analysing the scientific process in terms of (conceptual) mathematical models of theories and the various semantic relations between such models, scientific theories, and aspects of reality. In current philosophy of science, the most interesting questions centre around the ways in which writers distinguish between theories and the mathematical structures that interpret them and in which they are true, i.e. between scientific theories as linguistic (...) systems and their non-linguistic models. In philosophy of science literature there are two main approaches to the structure of scientific theories, the statement or syntactic approach -- advocated by Carnap, Hempel and Nagel -- and the non- statement or semantic approach --advocated, among others, by Suppes, the structuralists, Beth, Van Fraassen, Giere, Wojcicki. In conclusion, I briefly review some of the usual realist inspired questions about the possibility and character of relations between scientific theories and reality as implied by the various approaches I discuss in the course of the article. The models of a scientific theory should indeed be adequate to the phenomena, but if the theory is 'adequate' to (true in) its conceptual (mathematical) models as well, we have a model-theoretic realism that addresses the possible meaning and reference of 'theoretical entities' without relapsing into the metaphysics typical of the usual scientific realist approaches. (shrink)

Il y a un dilemme de la philosophie scientifique, limitée ici pour simplifier à la philosophie scientifique des sciences, assez évident dans lequel Carnap se trouve pris, mais auquel ni lui ni, sauf erreur de ma part, ses successeurs et commentateurs n’ont cru devoir s’arrêter : Ou bien la philosophie en question est scientifique au même sens que les autres sciences, c’est-à-dire ici qu’elle est elle-même l’une des sciences qu’elle a pour objets. On se demande alors à quoi pourrait ressembler (...) plus précisément une telle philosophie scientifique, à supposer qu’elle fût possible. Ou bien la philosophie en question n’est pas scientifique au sens des autres sciences, c’est-à-dire ici qu’elle est la seule qui puisse les prendre toutes pour objets, mais la seule aussi qu’elle ne puisse prendre pour objet. La prétendue philosophie scientifique des sciences n’est alors pas la philosophie de toutes les sciences, c’est seulement une philo­sophie des sciences non philosophiques. Ce dilemme vaut pour la philosophie scientifique en général et pour celle de Carnap en particulier, pour laquelle il prend une forme assez tranchante pour qu’on puisse en discuter sérieusement, surtout si l’on s’en tient à la philosophie scientifique des sciences identifiée par Carnap, à l’époque de la Syntax, à l’étude syntaxique, ou syntaxe, du Langage de la science. La réponse négative, savante et incontestée qu’il conviendrait alors d’apporter à la question cruciale de la première branche est connue : non, une syntaxe adéquate du Langage de la science dans ce Langage même est impossible, à moins que celui-ci ne soit inconsistant. Dans le présent article, on propose une formulation et une esquisse de démonstration inhabituelles de cette impossibilité, ne mobilisant aucun codage, gödélien ou autre, de la syntaxe élémentaire du Langage de la science dans ce Langage même ; et l’on remet en cause le critère d’adéquation impliqué dans la démonstration de l’impossibilité en question, rouvrant ainsi la possibilité de sortir par le haut d’un dilemme dont Carnap s’est cru obligé, ou du moins s’est conduit comme s’il était obligé, de sortir par le bas. (shrink)

Il y a un dilemme de la philosophie scientifique, limitée ici pour simplifier à la philosophie scientifique des sciences, assez évident dans lequel Carnap se trouve pris, mais auquel ni lui ni, sauf erreur de ma part, ses successeurs et commentateurs n’ont cru devoir s’arrêter : Ou bien la philosophie en question est scientifique au même sens que les autres sciences, c’est-à-dire ici qu’elle est elle-même l’une des sciences qu’elle a pour objets. On se demande alors à quoi pourrait ressembler (...) plus précisément une telle philosophie scientifique, à supposer qu’elle fût possible. Ou bien la philosophie en question n’est pas scientifique au sens des autres sciences, c’est-à-dire ici qu’elle est la seule qui puisse les prendre toutes pour objets, mais la seule aussi qu’elle ne puisse prendre pour objet. La prétendue philosophie scientifique des sciences n’est alors pas la philosophie de toutes les sciences, c’est seulement une philo­sophie des sciences non philosophiques. Ce dilemme vaut pour la philosophie scientifique en général et pour celle de Carnap en particulier, pour laquelle il prend une forme assez tranchante pour qu’on puisse en discuter sérieusement, surtout si l’on s’en tient à la philosophie scientifique des sciences identifiée par Carnap, à l’époque de la Syntax, à l’étude syntaxique, ou syntaxe, du Langage de la science. La réponse négative, savante et incontestée qu’il conviendrait alors d’apporter à la question cruciale de la première branche est connue : non, une syntaxe adéquate du Langage de la science dans ce Langage même est impossible, à moins que celui-ci ne soit inconsistant. Dans le présent article, on propose une formulation et une esquisse de démonstration inhabituelles de cette impossibilité, ne mobilisant aucun codage, gödélien ou autre, de la syntaxe élémentaire du Langage de la science dans ce Langage même ; et l’on remet en cause le critère d’adéquation impliqué dans la démonstration de l’impossibilité en question, rouvrant ainsi la possibilité de sortir par le haut (en restant sur la première branche) d’un dilemme dont Carnap s’est cru obligé, ou du moins s’est conduit comme s’il était obligé, de sortir par le bas (en se repliant sur la seconde). (shrink)

Powers are properties defined by what they do. The focus of the large majority of the powers literature has been mainly put on explicating the (multifaceted) results of the production of a power in certain (multifaceted) initial conditions: but all this causal complexity is bound to be—and, in fact, it has proved to be—quite difficult to handle. In this paper we take a different approach by focusing on the very activity of producing those multifaceted manifestations themselves. In this paper, we (...) propose an original account of what the essence of a power consists in which stems from a radical reconceptualisation of power-causation according to which counterfactuals are to be explained away by powers, and not vice-versa. We call this approach the dynamical operator account of powers. According to this account, the causal role of powers consists in their ensuring that the ontological transition from a stimulus S to a manifestation M happens. Powers thus have a dynamical essence which consists in the fundamental activity of generating the counterfactuals typically associated with them. We show that if one conceptualises this functional activity as the metaphysical fulcrum around which counterfactual-based causation revolves, one is granted not only an improved methodology to individuate powers but also a better understanding of their knowability, modality and directedness. (shrink)

According to Ole Hjortland, Timothy Williamson, Graham Priest, and others, anti-exceptionalism about logic is the view that logic “isn’t special”, but is continuous with the sciences. Logic is revisable, and its truths are neither analytic nor a priori. And logical theories are revised on the same grounds as scientific theories are. What isn’t special, we argue, is anti-exceptionalism about logic. Anti-exceptionalists disagree with one another regarding what logic and, indeed, anti-exceptionalism are, and they are at odds with naturalist philosophers of (...) logic, who may have seemed like natural allies. Moreover, those internal battles concern well-trodden philosophical issues, and there is no hint as to how they are to be resolved on broadly scientific grounds. We close by looking at three of the founders of logic who may have seemed like obvious enemies of anti-exceptionalism—Aristotle, Frege, and Carnap—and conclude that none of their positions is clearly at odds with at least some of the main themes of anti-exceptionalism. We submit that, at least at present, anti-exceptionalism is too vague or underspecified to characterize a coherent conception of logic, one that stands opposed to more traditional approaches. (shrink)

The text- and argument-focused histories of philosophy that we have are mainly interested in teasing out the details of the positions taken on philosophical issues by individual philosophers. But this is a long way from having a historical explanation of the larger-scale trajectory of philosophical development. An empirical history of philosophy, however, examines the institutionalized places and venues for philosophical work that provide a rich, shared structure for the promotion of particular sorts of work. Mid-twentieth-century philosophers of science such as (...) Herbert Feigl and Philipp Frank knew what they were doing—they were creating the space to promote certain sorts of work in venues such as the Institute for the Unity of Science and the Minnesota Center for Philosophy of Science and, ultimately, in publication venues such as Daedalus and the Minnesota Studies in Philosophy of Science. Here the engine of progress is the institution-building activity of committed philosophers making a space within the institutional structures of philosophy for their own projects and other projects aligned with them and transmitting these as live philosophical projects to the next generation. (shrink)

This essay looks at some of the key aspects of Hans Reichenbach’s career as a radio engineer, broadcaster, and producer. It argues that some of the themes of Reichenbach’s logical empiricism can be illuminated by looking at them in relation to his work as a radio engineer during and after World War One. It also argues that attention to the educational activities he undertook in the new broadcast radio medium can help us understand that affinities he saw between logical empiricism (...) and other modernizing projects of Weimar Germany. (shrink)

As Price (2009) famously mused, if a philosopher were to be magically transported, perhaps through means of time travel, from the 1950s to the modern day, they would indeed be shocked by the resurgence of metaphysics in the analytic tradition. Most of all, perhaps, they would be shocked by the popularity of power metaphysics. What a strange item to have in a philosopher’s curriculum, they might think: after all, didn’t David Hume claim that “[t]here are no ideas which can occur (...) in metaphysics more obscure and uncertain than those of power, force, energy, or necessary connection”? Indeed, much has changed since then. At the pain of using overly vague terminology, we can call “power metaphysics” the subdiscipline of metaphysics interested in the development and evaluation of a family of positions which we will refer to under the umbrella term of “dispositionalism”. According to dispositionalists, the world we inhabit is also populated by genuine and irreducible powers, dispositions, and capacities of objects. (shrink)

It is argued that the recent revival of theakrasia problem in the philosophy of mind is adirect, albeit unforeseen result of the debate onaction explanation in the philosophy of science. Asolution of the problem is put forward that takesaccount of the intimate links between the problem ofakrasia and this debate. This solution is basedon the idea that beliefs and desires have degrees ofstrength, and it suggests a way of giving a precisemeaning to that idea. Finally, it is pointed out thatthe (...) solution captures certain intuitions of bothSocrates and Aristotle. (shrink)

The main puzzle about theoretical definitions is that nothing seems to decide which assumptions contribute to such definitions and which do not. I argue that theoretical definitions are indeed imprecise, but that this does not normally matter, since the definitional imprecision does not normally produce indeterminacy of referential value. Sometimes, however, the definitional imprecision is less benign, and does generate referential indeterminacy. In these special cases, but not otherwise, it is necessary to refine the term's definition.

Tarski, Carnap and Quine spent the academic year 1940?1941 together at Harvard. In their autobiographies, both Carnap and Quine highlight the importance of the conversations that took place among them during the year. These conversations centred around semantical issues related to the analytic/synthetic distinction and on the project of a finitist/nominalist construction of mathematics and science. Carnap's Nachlaß in Pittsburgh contains a set of detailed notes, amounting to more than 80 typescripted pages, taken by Carnap while these discussions were taking (...) place. In my article, I present a survey of these notes with special emphasis on Tarski's rejection of the analytic/synthetic distinction, the passage from typed languages to first-order languages, Tarski's finitism/nominalism, and the construction of a finitist language for mathematics and science. (shrink)

In Our Knowledge of the Internal World, Robert Stalnaker describes two opposed perspectives on the relation between the internal and the external. According to one, the internal world is taken as given and the external world as problematic, and according to the other, the external world is taken as given and the internal world as problematic. Analytic philosophy moved from the former to the latter, from problems of world-construction to problems of self-locating beliefs. I argue in this paper that these (...) problems are equivalent: both arise because experience and objective, external facts jointly underdetermine their relation. Both can be seen as a problem of expressive completeness; of the internal language in the former case, and of the non-indexical language in the second. (shrink)

Susan Mills and John Beatty's propensity interpretation of fitness encountered very different philosophical criticisms by Alexander Rosenberg and Kenneth Waters. These criticisms and the rejoinders to them are both predictable and important. They are predictable as raisingkinds of issues typically associated with disposition concepts (this is established through a systematic review of the problems generated by Carnap's dispositional interpretation of all scientific terms). They are important as referring the resolution of these issues to the development of evolutionary biology. This historical (...) approach to the propensity interpretation of fitness draws attention to the precarious relation between philosophical clarification of scientific concepts and any given state of the empirical arts. (shrink)

Hans Reichenbach’s position in the debate over scientific realism is remarkable. On the one hand, he endorsed the programmatic premises of logical empiricism; on the other, he explicitly employed a realist approach to conceptions such as reference, causality, and inference to the best explanation. How could that work out? It will be shown in the present paper that in Reichenbach’s view scientific realism is not, as frequently assumed, opposed to logical empiricism but rather to logical positivism. A distinction without a (...) difference? Not at all, at least for Reichenbach. As is well known, his particular—probabilistic—variant of logical empiricism was intended to circumvent what he considered the shortcomings of the Vienna Circle’s verificationist approach to the language of science. In Experience and Prediction, Reichenbach became most explicit in this regard. However, I shall argue that his position remained notoriously unstable in the end. It oscillated between a full-fledged scientific realist reading and an eminently pragmatist reading. Nevertheless, Reichenbach’s contribution proved instrumental in preparing subsequent efforts at reconciling logical empiricism and scientific realism. (shrink)

Eino Kaila's thought occupies a curious position within the logical empiricist movement. Along with Hans Reichenbach, Herbert Feigl, and the early Moritz Schlick, Kaila advocates a realist approach towards science and the project of a “scientific world conception”. This realist approach was chiefly directed at both Kantianism and Poincaréan conventionalism. The case in point was the theory of measurement. According to Kaila, the foundations of physical reality are characterized by the existence of invariant systems of relations, which he called structures. (...) In a certain sense, these invariant structures, he maintained, are constituted in the act of measuring. By “constitution”, however, Kaila meant neither the dependency of the objects of measurement on a priori concepts (or Kantian categories) nor their being effected by conventional stipulations in a Poincaréan sense. He held that invariant structures are, quite literally, real: they exist prior to and independently of our theoretical capacity. By executing measurements, invariant structures are detected and objectively determinable by laws of nature. (shrink)

This article considers the evolution of Feigl's attempt at establishing a stable form of scientific realism. I will argue that Feigl's work in that area should be appreciated for two reasons: it represents a telling case against the view of there being an unbridgeable ‘analytic-continental divide’ in the context of twentieth-century philosophy; it contradicts the idea that scientific realism is at odds with logical empiricism. It will be shown that Feigl developed his scientific realist position from within the logical empiricists’ (...) Vienna Circle. This, in turn, necessitates a fresh approach toward the contemporary scientific realism debate. (shrink)

This chapter contains sections titled: Highlights of Past Literature Current Work Future Work.

This essay presents a model-theoretic account of dispositional properties, according to which dispositions are not ordinary properties of real entities; dispositions capture the behavior of abstract, idealized models. This account has several payoffs. First, it saves the simple conditional analysis of dispositions. Second, it preserves the general connection between dispositions and regularities, despite the fact that some dispositions are not grounded in actual regularities. Finally, it brings together the analysis and the explanation of dispositions under a unified framework.

The aim of this paper is to discuss the “Austro-American” logical empiricism proposed by physicist and philosopher Philipp Frank, particularly his interpretation of Carnap’s Aufbau, which he considered the charter of logical empiricism as a scientific world conception. According to Frank, the Aufbau was to be read as an integration of the ideas of Mach and Poincaré, leading eventually to a pragmatism quite similar to that of the American pragmatist William James. Relying on this peculiar interpretation, Frank intended to bring (...) about a rapprochement between the logical empiricism of the Vienna Circle in exile and American pragmatism. In the course of this project, in the last years of his career, Frank outlined a comprehensive, socially engaged philosophy of science that could serve as a “link between science and philosophy”. (shrink)

The paper presents an argument for treating certain types of computer simulation as having the same epistemic status as experimental measurement. While this may seem a rather counterintuitive view it becomes less so when one looks carefully at the role that models play in experimental activity, particularly measurement. I begin by discussing how models function as “measuring instruments” and go on to examine the ways in which simulation can be said to constitute an experimental activity. By focussing on the connections (...) between models and their various functions, simulation and experiment one can begin to see similarities in the practices associated with each type of activity. Establishing the connections between simulation and particular types of modelling strategies and highlighting the ways in which those strategies are essential features of experimentation allows us to clarify the contexts in which we can legitimately call computer simulation a form of experimental measurement. (shrink)

In his “Epistemology Naturalized,” Quine embraces a form of Humeanism. In this paper, I try to work out the significance of this Humeanism. In particular, I argue that it represents an anti-metaphysical position that Quine shares with Carnap. Crucial to my account is that contrary to much contemporary thinking on metaphysics, Carnap, and Quine following him, recognize both an ontological and an epistemological sense of metaphysics. As commentators have frequently acknowledged, Carnap and Quine disagree over rejecting metaphysics in the ontological (...) sense. I will argue, though, that they agree in rejecting metaphysics in their shared epistemological sense of the term. (shrink)

Value judgments are meaningless. This thesis was one of the notorious tenets of Carnap's mature logical empiricism. Less well known is the fact that in the Aufbau values were considered as philosophically respectable entities that could be constituted from value experiences. About 1930, however, values and value judgments were banished to the realm of meaningless metaphysics, and Carnap came to endorse a strict emotivism. The aim of this paper is to shed light on the question why Carnap abandoned his originally (...) positive attitude concerning values. It is argued that his non-cognitivist attitude was the symptom of a deep-rooted and never properly dissolved tension between conflicting inclinations towards Neokantianism and Lebensphilosophie. In America Carnap's non-cognitivism became a major obstacle for a closer collaboration between logical empiricists and American pragmatists. Carnap's persisting adherence to the dualism of practical life and theoretical science was the ultimate reason why he could not accept Morris's and Kaplan's pragmatist theses that cognitivism might well be compatible with a logical and empiricist scientific philosophy. (shrink)

The article discusses Friedman's classic claim that economics can be based on irrealistic assumptions. It exploits Samuelson's distinction between two "F-twists" (that is, "it is an advantage for an economic theory to use irrealistic assumptions" vs "the more irrealistic the assumptions, the better the economic theory"), as well as Nagel's distinction between three philosophy-of-science construals of the basic claim. On examination, only one of Nagel's construals seems promising enough. It involves the neo-positivistic distinction between theoretical and non-theoretical ("observable") terms; so (...) Friedman would in some sense argue for the major role of theoretical terms in economics. The paper uses a model-theoretic apparatus to refine the selected construal and check whether it can be made to support the claim. This inquiry leads to essentially negative results for both F-twists, and the final conclusion is that they are left unsupported. (shrink)

Man kann die Unterscheidung zwischen synthetischen und analytischen Sätzen aus zwei Perspektiven betrachten – von innen oder von außen: mit Blick auf die eigene Sprache oder mit Blick auf die Sprache anderer. Wer die Außenperspektive einnimmt, sucht eine Antwort auf die deskriptive Frage, welche Sätze einer fremden Sprache als analytisch zu klassifizieren sind. Wer die Innenperspektive einnimmt, sucht dagegen eine Antwort auf folgende normative Frage: Welche Sätze darf ich nicht preisgeben oder zurückweisen – wenn ich keinen Unfug reden will? Die (...) beiden Blickwinkel schließen einander nicht aus; sie ergänzen sich und unterstützen einander. In seinem Aufsatz „Two dogmas of empiricism“ kritisiert Quine die Unterscheidung zwischen synthetischen und analytischen Sätzen aus der Innenperspektive; in seinem Buch Word and object wiederholt er dieselbe Kritik aus der Außenperspektive. In beiden Fällen richtet sich seine Kritik gegen die Ziele des frühen Carnap (der sämtliche Ausdrücke der Wissenschaftssprache mithilfe analytisch wahrer Definitionen verständlich machen wollte). Ich trete beiden Fassungen dieser Kritik entgegen und schlage zwei Definitionen des Begriffs vom analytischen Satz vor, die Quines Kritik entgehen: eine Definition aus der Außen- und eine aus der Innenperspektive. Zum Abschluss führe ich in einer leicht spekulativen Betrachtung vor, wie man bloßen Begriffswandel vom Wandel der inhaltlichen Überzeugungen trennen könnte – und zwar sogar im Fall wissenschaftlicher Revolutionen. (shrink)

An amended bootstrapping can avoid Christensen's counterexamples. Earman and Edidin argue that Christensen's examples to bootstrapping rely on his failure to analyze background knowledge. I add an additional condition to bootstrapping that is motivated by Glymour's remarks on variety of evidence. I argue that it avoids the problems that the examples raise. I defend the modification against the charge that it is holistic, and that it collapses into Bayesianism.

It is widely accepted that embodiment is crucial for any self-aware agent. What is less obvious is whether the body has to be real, or whether a virtual body will do. In that case the notion of embodiment would be so attenuated as to be almost indistinguishable from disembodiment. In this article I concentrate on the notion of embodiment in human agents. Could we be disembodied, having no real body, as brains-in-a-vat with only a virtual body? Thought experiments alone will (...) not suffice to answer this Cartesian question. I will draw on both philosophical arguments and empirical data on phantom phenomena. My argument will proceed in three steps. Firstly I will show that phantom phenomena provide a prima facie argument that real embodiment is not necessary for a human being. Secondly I will give a philosophical argument that real movement must precede the intention to move and to act. Agents must at least have had real bodies once. Empirical data seems to bear this out. Finally, however, I will show that a small number of aplasic phantom phenomena undermines this last argument. Most people must have had a real body. But for some people a partly virtual, unreal, phantom body seems to suffice. Yet though there is thus no knockdown argument that we could not be brains-in-a-vat, we still have good reasons to suppose that embodiment must be real, and not virtual. (shrink)

Reid offers an under-appreciated account of the primary/secondary quality distinction. He gives sound reasons for rejecting the views of Locke, Boyle, Galileo and others, and presents a better alternative, according to which the distinction is epistemic rather than metaphysical. Primary qualities, for Reid, are qualities whose intrinsic natures can be known through sensation. Secondary qualities, on the other hand, are unknown causes of sensations. Some may object that Reid's view is internally inconsistent, or unacceptably relativistic. However, a deeper understanding shows (...) that it is consistent, and relative only to normal humans. To acquire this deeper understanding, one must also explore the nature of dispositions, Reid's rejection of the theory of ideas, his distinction between sensation and perception, and his distinction between natural and acquired perceptions. (shrink)

Reid offers an under‐appreciated account of the primary/secondary quality distinction. He gives sound reasons for rejecting the views of Locke, Boyle, Galileo and others, and presents a better alternative, according to which the distinction is epistemic rather than metaphysical. Primary qualities, for Reid, are qualities whose intrinsic natures can be known through sensation. Secondary qualities, on the other hand, are unknown causes of sensations. Some may object that Reid's view is internally inconsistent, or unacceptably relativistic. However, a deeper understanding shows (...) that it is consistent, and relative only to normal humans. To acquire this deeper understanding, one must also explore the nature of dispositions, Reid's rejection of the theory of ideas, his distinction between sensation and perception, and his distinction between natural and acquired perceptions. (shrink)

Jaegwon Kim and others have claimed that (strong) psychophysical supervenience entails the reducibility of mental properties to physical properties. I argue that this claim is unwarranted with respect to epistemic (explanatory) reducibility (either of a global or of a local sort), as well as with respect to ontological reducibility. I then attempt to show that a robust version of nonreductive materialism (which I call supervenient token-physicalism) can be defended against the charge that nonreductive materialism leads to epiphenomenalism in failing to (...) account for the causal or explanatory relevance of mental properties. (shrink)

For several decades, Carnap's philosophy of mathematics used to be either dismissed or ignored. It was perceived as a form of linguistic conventionalism and thus taken to rely on the bankrupt notion of truth by convention. However, recent scholarship has revealed a more subtle picture. It has been forcefully argued that Carnap is not a linguistic conventionalist in any straightforward sense, and that supposedly decisive objections against his position target a straw man. This raises two questions. First, how exactly should (...) we characterise Carnap's actual philosophy of mathematics? Secondly, is his position an attractive alternative to established views? I will tackle these issues by looking at Carnap's response to the incompleteness theorems. Drawing on arguments put forward by Gödel and Beth, I show that some crucial aspects of Carnap's positive account have remained underdeveloped. Suggestions on what a full evaluation of Carnap's position requires are made. (shrink)

What are Carnap's views on the epistemology of mathematics? Did he believe in a priori justification, and if so, what is his account of it? One might think that such questions are misguided, since in the 1930s Carnap came to reject traditional epistemology as a confused mixture of logic and psychology. But things are not that simple. Drawing on recent work by Richardson and Uebel, I will show that Carnap's mature metaphilosophy leaves room for two distinct notions of a priori (...) justification: one propositional, the other doxastic. The latter is especially interesting since it comes closest to a traditional understanding of a priority. On the other hand, Carnap has little to say about doxastic justification in his writings. This lacuna can be filled by drawing on an unpublished exchange with Irving M. Copi. In it, so I will show, Carnap endorses the view that agents can come to know all mathematical truths a priori. This fact, so I will further argue, can be used to adjudicate a dispute between Ricketts and Friedman about the nature and viability of Carnap's philosophy of mathematics—specifically his reliance on infinitary methods. (shrink)

Rudolf Carnap’s principle of tolerance states that there is no need to justify the adoption of a logic by philosophical means. Carnap uses the freedom provided by this principle in his philosophy of mathematics: he wants to capture the idea that mathematical truth is a matter of linguistic rules by relying on a strong metalanguage with infinitary inference rules. In this paper, I give a new interpretation of an argument by E. W. Beth, which shows that the principle of tolerance (...) does not suffice to remove all obstacles to the employment of infinitary rules. (shrink)

The aim of this paper is twofold. Firstly, I give a brief account of the history of the debate on the problem of defining disposition concepts from its beginning in the late 1920s until today. This account is divided into four parts, corresponding with 2, 3, 4 and 5 of the paper, each of which deals with a major period of the debate. Section 2 reports up to the mid-1950s. Section 3 deals with important contributions to the discussion between 1955 (...) and 1958. However, the progress made around that time was far ahead of the logical theory and techniques which were needed for foundational reasons and for a better understanding of the basic notions. Some logical techniques appropriate for that aim were developed in the late 1960s and early 1970s. Though not uncontroversial, those logical techniques resulted in improvements of the insights gained in the mid-1950s; I shall report on those logical techniques and their application to the problem of defining disposition concepts in Section 4. In the early 1990s, however, the whole tradition of defining disposition concepts in terms of conditionals has been challenged by some strong counter-examples which are treated in Section 5. Finally, the second of the aims of this paper is explored in Section 6, in which I sketch very briefly the current stage of the debate by discussing and evaluating the most recent approaches to the subject. (shrink)

I propose a semantics for a class of English predicates characteristically associated with possibility. The central idea is that such predicates are typically associated with an ordering source, and that differences among them are due to differences in their ordering sources. The ‘dispositional predicates’ that have been central to philosophical discussions are shown to be derivable as a special case from this more general class.

While I do not accept any current analysis of theoretical terms I also reject certain criticisms of them. Specifically, I reject the criticism that the paradoxes of material implication and the counterfactual problem eliminate the explicit definition view; and I also reject the criticism that explicitly defined theoretical terms do not refer to anything which "really exists" or do not have "excess meaning." I do argue, however, that the explicit definition view confuses and conflates the concepts of criterion and meaning (...) analysis. I also defend reduction sentences against the counterfactual difficulty, but show, too, how this view is already logically committed to the network or postulational view of meaning. Finally, I show how the concept of reduction sentences confuses in several ways the concepts of criterion and meaning analysis--although not in quite the same way as explicit definitions do. (shrink)