Rudolf Carnap

Friedrich Nietzsche was among the figures from the history of nineteenth century philosophy that, perhaps surprisingly, some of the Vienna Circle’s members had presented as one of their predecessors. While, primarily for political reasons, most Anglophone figures in the history of analytic philosophy had taken a dim view of Nietzsche, the Vienna Circle’s leader Moritz Schlick admired and praised Nietzsche, rejecting what he saw as a misinterpretation of Nietzsche as a militarist or proto-fascist. Schlick, Frank, Neurath, and Carnap were in (...) different ways committed to the view that Nietzsche made a significant contribution to the overcoming of metaphysics. Some of these philosophers praised the intimate connection Nietzsche drew between his philosophical outlook and empirical studies in psychology and physiology. In his 1912 lectures on Nietzsche, Schlick maintained that Nietzsche overcame an initial Schopenhauerian metaphysical-artistic phase in his thinking, and subsequently remained a positivist until his last writings. Frank and Neurath made the weaker claim that Nietzsche contributed to the development of a positivistic or scientific conception of the world. Schlick and Frank took a further step in seeing the mature Nietzsche as an Enlightenment thinker. (shrink)

W. V. Quine’s first philosophical monograph, Word and Object, is widely recognized as one of the most influential books of twentieth century philosophy. Notes, letters, and draft manuscripts at the Quine Archives, however, reveal that Quine was already working on a philosophical book in the early 1940s; a project entitled Sign and Object. In this paper, I examine these and other unpublished documents and show that Sign and Object sheds new light on the evolution of Quine’s ideas. Where “Two Dogmas (...) of Empiricism” is usually considered to be a turning point in Quine’s development, this paper redefines the place of ‘Two Dogmas’ in his oeuvre. Not only does Quine’s book project reveal that his views were already fairly naturalistic in the early 1940s ; Sign and Object also unearths the steps Quine had to take in maturing his perspective; steps that will be traced in the second half of this paper. (shrink)

This paper gives a historical overview of the rise and fall of the Vienna Circle. It also explains its philosophical roots, methodological principles, the scientific world-conception it promoted, and how it influenced later generations of philosophers.

A. J. Ayer’s Language, Truth, and Logic had been responsible for introducing the Vienna Circle’s ideas, developed within a Germanophone framework, to an Anglophone readership. Inevitably, this migration from one context to another resulted in the alteration of some of the concepts being transmitted. Such alterations have served to facilitate a number of false impressions of Logical Empiricism from which recent scholarship still tries to recover. In this paper, I will attempt to point to the ways in which LTL has (...) helped to foster the various mistaken stereotypes about Logical Empiricism which were combined into the received view. I will begin by examining Ayer’s all too brief presentation of an Anglocentric lineage for his ideas. This lineage, as we shall see, simply omits the major 19th century Germanophone influences on the rise of analytic philosophy. The Germanophone ideas he presents are selectively introduced into an Anglophone context, and directed towards various concerns that arose within that context. I will focus on the differences between Carnap’s version of the overcoming of metaphysics, and Ayer’s reconfiguration into what he calls the elimination of metaphysics. Having discussed the above, I will very briefly outline the consequences that Ayer’s radicalisation of the Vienna Circle’s doctrines had on the subsequent Anglophone reception of Logical Empiricism. (shrink)

Due to their acceptance of the verifiability principle, the only way left for logical positivists to argue for the meaningfulness of religious language was to accept some sort of emotivistic conception of it or to reduce it to the description of religious attitude. The verifiability principle, however, suffers from some severe limitations that make it inadequate as a criterion for cognitive meaning. To resolve these problems, logical positivists gave up the requirement of conclusive verifiability and defended a sort of ‘liberalization’ (...) of the verifiability principle. Carnap’s confirmability criterion for cognitive meaning, which is a liberalized form of the verifiability principle, is compatible with an orthodox conception of religious language since, from a theistic perspective, the existence of God can be confirmed through our observational statements. (shrink)

During the past few decades, a radical shift has occurred in how philosophers conceive of the relation between science and philosophy. A great number of analytic philosophers have adopted what is commonly called a ‘naturalistic’ approach, arguing that their inquiries ought to be in some sense continuous with science. Where early analytic philosophers often relied on a sharp distinction between science and philosophy—the former an empirical discipline concerned with fact, the latter an a priori discipline concerned with meaning—philosophers today largely (...) follow Willard Van Orman Quine (1908-2000) in his seminal rejection of this distinction. -/- This book offers a comprehensive study of Quine’s naturalism. Building on Quine’s published corpus as well as thousands of unpublished letters, notes, lectures, papers, proposals, and annotations from the Quine archives, this book aims to reconstruct both the nature (chapters 2-4) and the development (chapter 5-7) of his naturalism. As such, this book aims to contribute to the rapidly developing historiography of analytic philosophy, and to provide a better, historically informed, understanding of what is philosophically at stake in the contemporary naturalistic turn. (shrink)

Contemporary analytic philosophy is dominated by metaphilosophical naturalism, the view that philosophy ought to be continuous with science. This naturalistic turn is for a significant part due to the work of W. V. Quine. Yet, the development and the reception of Quine’s naturalism have never been systematically studied. In this paper, I examine Quine’s evolving naturalism as well as the reception of his views. Scrutinizing a large set of unpublished notes, correspondence, drafts, papers, and lectures as well as published responses (...) to Quine’s work, I show how both internal tensions and external criticisms forced him to continuously develop, rebrand, and refine his metaphilosophy before he explicitly decided to label his view ‘naturalism’ in the late 1960s. (shrink)

The main task in this paper is to detail and investigate Carnap’s conception of a “linguistic framework”. On this basis, we will see whether Carnap’s dichotomies, such as the analytic-synthetic distinction, are to be construed as absolute/fundamental dichotomies or merely as relative dichotomies. I argue for a novel interpretation of Carnap’s conception of a LF and, on that basis, will show that, according to Carnap, all the dichotomies to be discussed are relative dichotomies; they depend on conventional decisions concerning the (...) logical syntax of LF. Thus, all of the dichotomies directly hinge on the conception of the LF. The LF’s logical structure, in turn, is an immediate consequence of adopting the linguistic doctrine of logical truths. As we will see, no appeal to any of these distinctions is necessary in establishing a LF and all of its components. I will also draw attention to the differences between what Carnap labels a “way of speaking”, “language”, and “artificial language”. Consequently, I will briefly conclude that none of Quine’s major objections address the main points of Carnap’s theory. (shrink)

This paper takes up the challenge which Carnap poses in his Aufbau: to make of it a basis for continued epistemological research. I try to close some gaps in Carnap’s original presentation and to make at least the first few steps of his constructional outline more accessible to the modern reader. Particularly emphasized is Carnap’s implicit recognition that, to be effective, “structural” models of epistemology (using logical symbols) must be complemented with “procedural” models (his “fictitious operations”). The paper shows how (...) a procedural model, a computer program,can “bypass” Nelson Goodman’s counter example to Carnap’s logical construction of “similarity circles”. (shrink)

Geometry was a main source of inspiration for Carnap’s conventionalism. Taking Poincaré as his witness Carnap asserted in his dissertation Der Raum (Carnap 1922) that the metrical structure of space is conventional while the underlying topological structure describes "objective" facts. With only minor modifications he stuck to this account throughout his life. The aim of this paper is to disprove Carnap's contention by invoking some classical theorems of differential topology. By this means his metrical conventionalism turns out to be indefensible (...) for mathematical reasons. This implies that the relation between to-pology and geometry cannot be conceptualized as analogous to the relation between the meaning of a proposition and its expression in some language as logical empiricists used to say. (shrink)

In Der logische Aufbau der Welt, first published in 1928, Carnap aims to rationally reconstruct all objects of cognition by logico-definitional means. As a result, he intends to obtain a fully objective framework in which scientific discourse can take place. This is made possible by the novel method of ‘purely structural definite description’ of all scientifically relevant objects, which is first introduced in the Aufbau. Key to the attainment of this goal is the notion of ‘foundedness’, which Carnap presents as (...) a new basic notion of logic, in order to establish a link between the purely conventional world of logical and mathematical knowledge and the empirical world of knowledge of scientific objects. This idea experienced major criticism by Friedman (1999a,b) since he considers it to lead to the demolition of the boundary between those two worlds. In this essay, we want to defend foundedness against Friedman’s critique by arguing that its introduction is necessary within Carnap’s logicist world of thought to deal with a more fundamental problem: the demarcation of the empirical parts of the Aufbau. In the last section, we will give an outlook on the actual cause for the failure of the Aufbau, the lack of a principle to determine the truth of the instances of the basic relation in the Aufbau, and we will show how this can contribute to the explanation of Carnap’s future philosophical development and retrospective self-evaluation. This essay serves as a dense informal sketch for a later extensive formal treatment of this reading of foundedness and focuses on its implications for the interpretation of Carnap’s post-Aufbau development. (shrink)

Many who take a dismissive attitude towards metaphysics trace their view back to Carnap’s ‘Empiricism, Semantics and Ontology’. But the reason Carnap takes a dismissive attitude to metaphysics is a matter of controversy. I will argue that no reason is given in ‘Empiricism, Semantics and Ontology’, and this is because his reason for rejecting metaphysical debates was given in ‘Pseudo-Problems in Philosophy’. The argument there assumes verificationism, but I will argue that his argument survives the rejection of verificationism. The root (...) of his argument is the claim that metaphysical statements cannot be justified; the point is epistemic, not semantic. I will argue that this remains a powerful challenge to metaphysics that has yet to be adequately answered. (shrink)

A brief introduction to the life and key work of Rudolf Carnap with special attention to his work on inductive logic.

The rise of experimental philosophy has placed metaphilosophical questions, particularly those concerning concepts, at the center of philosophical attention. X-phi offers empirically rigorous methods for identifying conceptual content, but what exactly it contributes towards evaluating conceptual content remains unclear. We show how x-phi complements Rudolf Carnap’s underappreciated methodology for concept determination, explication. This clarifies and extends x-phi’s positive philosophical import, and also exhibits explication’s broad appeal. But there is a potential problem: Carnap’s account of explication was limited to empirical and (...) logical concepts, but many concepts of interest to philosophers are essentially normative. With formal epistemology as a case study, we show how x-phi assisted explication can apply to normative domains. (shrink)

Against Thomas Mormann's argument that differential topology does not support Carnap's conventionalism in geometry we show their compatibility. However, Mormann's emphasis on the entanglement that characterizes topology and its associated metrics is not misplaced. It poses questions about limits of empirical inquiry. For Carnap, to pose a question is to give a statement with the task of deciding its truth. Mormann's point forces us to introduce more clarity to what it means to specify the task that decides between competing hypotheses (...) and in what way such a task may be both in practice and/or in principle impossible to carry out. (shrink)

Hume and Quine argue that human beings do not have access to general knowledge, that is, to general truths . The arguments of these two philosophers are premised on what Jaakko Hintikka has called the atomistic postulate. In the present work, it is shown that Hume and Quine in fact sanction an extreme version of this postulate, according to which even items of particular knowledge are not directly accessible in so far as they are relational. For according to their fully (...) realized systems, human beings do not initially perceive any relations, or similar epistemological elements that can associate or combine terms on which a relational or general knowledge claim may be based. Nor, likewise, do human beings perceive the relations or the associations themselves as separate entities. ;In Chapters 1 and 2, respectively, it is shown precisely why Hume and Quine deny that human beings initially perceive either such associative elements or associations in general. Concomitantly, it is made clear why Hume's and Quine's respective epistemologies preclude human beings from initially apprehending not only general knowledge, but particular relational knowledge as well. But this is not to say that Hume and Quine do not think we can eventually acquire such associative elements and correspondingly, knowledge. Rather, Hume and Quine do provide an account of knowledge, but one that holds all relational and connective elements to be constructed by the human mind. In Hume's case, they are constructed by the imagination. In Quine's case, we are never told quite how this construction occurs, although the evidence suggests that Quine implicitly relies on a faculty similar to Hume's imagination. ;In the final chapter of this thesis, it is argued that both Hume and Quine must be read as philosophers who justify knowledge by reducing its possibility to a psychological faculty of construction, as well as to a few concepts of intuitively grasped relations. By way of conclusion, it is shown that this makes Quine's naturalism the psychological heir to Carnap's Aufbau. (shrink)

The concept of similarity has had a rather mixed reputation in philosophy and the sciences. On the one hand, philosophers such as Goodman and Quine emphasized the „logically repugnant“ and „insidious“ character of the concept of similarity that allegedly renders it inaccessible for a proper logical analysis. On the other hand, a philosopher such as Carnap assigned a central role to similarity in his constitutional theory. Moreover, the importance and perhaps even indispensibility of the concept of similarity for many empirical (...) sciences can hardly be denied. The aim of this paper is to show that Quine’s and Goodman’s harsh verdicts about this notion are mistaken. The concept of similarity is susceptible to a precise logico-mathematical analysis through which its place in the conceptual landscape of modern mathematical theories such as order theory, topology, and graph theory becomes visible. Thereby it can be shown that a quasi-analysis of a similarity structure S can be conceived of as a sheaf (etale space) over S. (shrink)

An overview of Quine's understanding of the analytic/synthetic distinction, especially as it is conveyed in his paper, "The Two Dogmas of Empiricism.".

I argue that Quine’s rejection of Carnap’s “radical” (FLPV; TDE 39) and “phenomenalistic” (FSS 15-16) reductionism—as it is manifest in the Aufbau—may be understood in terms of a broader historical context. In particular, it may be understood as a rejection of a contemporary variant of the second horn of Meno’s Paradox. As a result, Quine’s motivation to adopt naturalism may be understood independently of his pragmatic concerns. According to Quine, it was simply unreasonable (i.e. paradoxical) to adopt a Carnapian phenomenalistic/mentalistic (...) (non-naturalistic) approach to epistemology. Armed with what could only be his invigorated faith in the naturalistic method, he was then, as I see it, equipped to break what we may characterize as the physicalistic version of the naturalistic circle. This is a repudiation that, I show, entails his rejection of “attenuated” (FLPV; TDE 41) reductionism and concomitantly, his rejection of “analyticity,” if not “certainty” altogether. As a result, Quine could simultaneously dismiss what we may characterize as the Humean version of the naturalistic circle. Meanwhile, the practicality of an admittedly fallible science could be unashamedly embraced, although not just for the sake of its practicality—as Quine himself seems to misleadingly indicate throughout his work—but instead, as just noted, to avoid the seemingly Platonic paradox of Aufbauian reductionism. (shrink)

Einführung in die Philosophie Rudolf Carnaps.

The verification theory of meaning aims to characterise what it is for a sentence to be meaningful and also what kind of abstract object the meaning of a sentence is. A brief outline is given by Rudolph Carnap, one of the theory's most prominent defenders: If we knew what it would be for a given sentence to be found true then we would know what its meaning is. [...] thus the meaning of a sentence is in a certain sense identical (...) with the way we determine its truth or falsehood; and a sentence has meaning only if such a determination is possible. [4: 420] In short, the verification theory of meaning claims that the meaning of a sentence is the method of its verification. (shrink)

This chapter explores some of the relations between Quine’s and Carnap’s metaontological stances on the one hand, and contemporary work in the metaphysics of time, on the other. Contemporary metaphysics of time, like analytic metaphysics in general, grew out of the revival of the discipline that Quine’s critique of the logical empiricists (such as Carnap) made possible. At the same time, the metaphysics of time has, in some respects, strayed far from its Quinean roots. This chapter examines some likely Quinean (...) and Carnapian reactions to elements of the contemporary scene. (shrink)

Many who take a dismissive attitude towards metaphysics trace their view back to Carnap’s ‘Empiricism, Semantics and Ontology’. But the reason Carnap takes a dismissive attitude to metaphysics is a matter of controversy. I will argue that no reason is given in ‘Empiricism, Semantics and Ontology’, and this is because his reason for rejecting metaphysical debates was given in ‘Pseudo-Problems in Philosophy’. The argument there assumes verificationism, but I will argue that his argument survives the rejection of verificationism. The root (...) of his argument is the claim that metaphysical statements cannot be justified; the point is epistemic, not semantic. I will argue that this remains a powerful challenge to metaphysics that has yet to be adequately answered. (shrink)

Quine is routinely perceived as saving metaphysics from Carnapian positivism. Where Carnap rejects metaphysical existence claims as meaningless, Quine is taken to restore their intelligibility by dismantling the former’s internal–external distinction. The problem with this picture, however, is that it does not sit well with the fact that Quine, on many occasions, has argued that metaphysical existence claims ought to be dismissed. Setting aside the hypothesis that Quine’s metaphysical position is incoherent, one has to conclude that his views on metaphysics (...) are subtler than is often presupposed; both the received view that Quine saved metaphysics and the opposite view that Carnap and Quine are on the same anti-metaphysical team seem too one-sided if we take seriously Quine’s own pronouncements on the issue. In this paper, I offer a detailed reconstruction of Quine’s perspective on metaphysical existence claims. Scrutinizing his published work as well as unpublished papers, letters, and notebooks, I show how Quine is able to both blur the boundary between scientific sense and metaphysical nonsense and to argue that we cannot ask what reality is really like in a distinctively philosophical way. I argue that although Quine’s position is much closer to Carnap’s than the received view suggests, it still differs in two crucial respects. (shrink)

Several recent works in history and philosophy of science have re-evaluated the alleged opposition between the theses put forth by logical empiricists such as Carnap and the so-called "post-positivists", such as Kuhn. Although the latter came to be viewed as having seriously challenged the logical positivist views of science, recent authors (e.g., Friedman, Reisch, Earman, Irzik and Grünberg) maintain that some of the most notable theses of the Kuhnian view of science have striking similarities with some aspects of Carnap's philosophy. (...) Against that reading, Oliveira and Psillos argue that within Carnap's philosophy there is no place for the Kuhnian theses of incommensurability, holism, and theory-ladenness of observations. This paper presents each of those readings and argues that Carnap and Kuhn have non-opposing views on holism, incommensurability, the theory-ladenness of observations, and scientific revolutions. We note at the very end - without dwelling on the point, however - that they come apart on other matters, such as their views on metaphysics and on the context of discovery/justification distinction. (shrink)

This paper argues that Carnap both did not view and should not have viewed Frege's project in the foundations of mathematics as misguided metaphysics. The reason for this is that Frege's project was to give an explication of number in a very Carnapian sense — something that was not lost on Carnap. Furthermore, Frege gives pragmatic justification for the basic features of his system, especially where there are ontological considerations. It will be argued that even on the question of the (...) independent existence of abstract objects, Frege and Carnap held remarkably similar views. I close with a discussion of why, despite all this, Frege would not accept the principle of tolerance. (shrink)

Rudolf Carnap's 1930s philosophy of logic, including his adherence to the principle of tolerance, is discussed. What theses did Carnap commit himself to, exactly? I argue that while Carnap did commit himself to a certain multitude thesis—there are different logics of different languages, and the choice between these languages is merely a matter of expediency—there is no evidence that he rejected a language-transcendent notion of fact, contrary to what Warren Goldfarb and Thomas Ricketts have prominently argued. (In fact, it is (...) obscure just what Goldfarb and Ricketts claim about Carnap). Toward the end I critically discuss Michael Friedman's suggestion that Carnap believed in a relative a priori. (shrink)

Einführung in die Philosophie Rudolf Carnaps.

My focus here will be Rudolf Carnap’s views on ontology, as these are presented in the seminal “Empiricism, Semantics and Ontology” (1950). I will first describe how I think Carnap’s distinction between external and internal questions is best understood. Then I will turn to broader issues regarding Carnap’s views on ontology. With certain reservations, I will ascribe to Carnap an ontological pluralist position roughly similar to the positions of Eli Hirsch and the later Hilary Putnam. Then I turn to some (...) interrelated arguments against the pluralist view. The arguments are not demonstrative. Some possible escape routes for the pluralist are outlined. But I think the arguments constitute a formidable challenge. There should be serious doubt as to whether the pluralist view, as it emerges after discussion of these arguments, will be worth defending. Moreover, there is an alternative ontological view which equally well subserves the motivations underlying ontological pluralism. (shrink)

It seems natural to think that Carnapian explication and experimental philosophy can go hand in hand. But what exactly explicators can gain from the data provided by experimental philosophers remains controversial. According to an influential proposal by Shepherd and Justus, explicators should use experimental data in the process of ‘explication preparation’. Against this proposal, Mark Pinder has recently suggested that experimental data can directly assist an explicator’s search for fruitful replacements of the explicandum. In developing his argument, he also proposes (...) a novel aspect of what makes a concept fruitful, namely, that it is taken up by the relevant community. In this paper, I defend explication preparation against Pinder’s objections and argue that his uptake proposal conflates theoretical and practical success conditions of explications. Furthermore, I argue that Pinder’s suggested experimental procedure needs substantial revision. I end by distinguishing two kinds of explication projects, and showing how experimental philosophy can contribute to each of them. (shrink)

The focus of the article is the self-predication principle, according to which the/a such-and-such is such-and-such. We consider contemporary approaches (Frege, Russell, Meinong) to the self-predication principle, as well as fourteenth-century approaches (Burley, Ockham, Buridan). In crucial ways, the Ockham-Buridan view prefigures Russell’s view, and Burley’s view shows a striking resemblance to Meinong’s view. In short the Russell-Ockham-Buridan view holds: no existence, no truth. The Burley-Meinong view holds, in short: intelligibility suffices for truth. Both views approach self-predication in a uniform (...) way. We were unable to find a medieval philosopher who, like Frege, approaches self-predication in a non-uniform way. We do not want to dispute that there are also considerable differences between the contemporary and the fourteenth-century approach to self-predication. Importantly, fourteenth-century accounts of self-predication rely strongly on the identity theory of predication, and this theory is not endorsed by contemporary philosophers of language. Nevertheless, some basic tenets seem to us to be clearly shared between fourteenth-century and contemporary thinkers. (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)

Several recent works in history and philosophy of science have re-evaluated the alleged opposition between the theses put forth by logical empiricists such as Carnap and the so-called "post-positivists", such as Kuhn. Although the latter came to be viewed as having seriously challenged the logical positivist views of science, recent authors (e.g., Friedman, Reisch, Earman, Irzik and Grünberg) maintain that some of the most notable theses of the Kuhnian view of science have striking similarities with some aspects of Carnap's philosophy. (...) Against that reading, Oliveira and Psillos argue that within Carnap's philosophy there is no place for the Kuhnian theses of incommensurability, holism, and theory-ladenness of observations. This paper presents each of those readings and argues that Carnap and Kuhn have non-opposing views on holism, incommensurability, the theory-ladenness of observations, and scientific revolutions. We note at the very end - without dwelling on the point, however - that they come apart on other matters, such as their views on metaphysics and on the context of discovery/justification distinction. (shrink)

Rudolf Carnap's 1930s philosophy of logic, including his adherence to the principle of tolerance, is discussed. What theses did Carnap commit himself to, exactly? I argue that while Carnap did commit himself to a certain multitude thesis—there are different logics of different languages, and the choice between these languages is merely a matter of expediency—there is no evidence that he rejected a language-transcendent notion of fact, contrary to what Warren Goldfarb and Thomas Ricketts have prominently argued. (In fact, it is (...) obscure just what Goldfarb and Ricketts claim about Carnap). Toward the end I critically discuss Michael Friedman's suggestion that Carnap believed in a relative a priori. (shrink)

Carnap's theory of descriptions was restricted in two ways. First, the descriptive conditions had to be non-modal. Second, only primitive predicates or the identity predicate could be used to predicate something of the descriptum . The motivating reasons for these two restrictions that can be found in the literature will be critically discussed. Both restrictions can be relaxed, but Carnap's theory can still be blamed for not dealing adequately with improper descriptions.

Einführung in die Philosophie Rudolf Carnaps.

Recent Carnap scholarship suggests that the received view of the Carnap-Quine analyticity debate is importantly mistaken. It has been suggested that Carnap’s analyticity distinction is immune from Quine’s criticisms. This is either because Quine did not understand Carnap’s use of analytic-ity, or because Quine did not appreciate that, rather than dispelling dog-mas, he was merely offering an alternate framework for philosophy. It has also been suggested that ultimately nothing of substance turns on this dis-pute. I am sympathetic to these reassessments (...) and their rejection of the re-ceived view, but argue that they fail to pay proper attention to Carnap’s metaphysical deflationism. For it is there that Quine’s arguments ultimately make contact with Carnap, undermining his metaphysical deflationism. Moreover, the viability of deflationism is directly related to the viability of Carnap’s view of philosophy as methodologically distinct from science. Hence, Quine’s criticisms make contact with the deepest aspects of Carnap’s views. (shrink)

In Der logische Aufbau der Welt, first published in 1928, Carnap aims to rationally reconstruct all objects of cognition by logico-definitional means. As a result, he intends to obtain a fully objective framework in which scientific discourse can take place. This is made possible by the novel method of ‘purely structural definite description’ of all scientifically relevant objects, which is first introduced in the Aufbau. Key to the attainment of this goal is the notion of ‘foundedness’, which Carnap presents as (...) a new basic notion of logic, in order to establish a link between the purely conventional world of logical and mathematical knowledge and the empirical world of knowledge of scientific objects. This idea experienced major criticism by Friedman (1999a,b) since he considers it to lead to the demolition of the boundary between those two worlds. In this essay, we want to defend foundedness against Friedman’s critique by arguing that its introduction is necessary within Carnap’s logicist world of thought to deal with a more fundamental problem: the demarcation of the empirical parts of the Aufbau. In the last section, we will give an outlook on the actual cause for the failure of the Aufbau, the lack of a principle to determine the truth of the instances of the basic relation in the Aufbau, and we will show how this can contribute to the explanation of Carnap’s future philosophical development and retrospective self-evaluation. This essay serves as a dense informal sketch for a later extensive formal treatment of this reading of foundedness and focuses on its implications for the interpretation of Carnap’s post-Aufbau development. (shrink)

Carnap’s result about classical proof-theories not ruling out non-normal valuations of propositional logic formulae has seen renewed philosophical interest in recent years. In this note I contribute some considerations which may be helpful in its philosophical assessment. I suggest a vantage point from which to see the way in which classical proof-theories do, at least to a considerable extent, encode the meanings of the connectives (not by determining a range of admissible valuations, but in their own way), and I demonstrate (...) a kind of converse to Carnap’s result. (shrink)

A brief introduction to the life and key work of Rudolf Carnap with special attention to his work on inductive logic.

We characterize those identities and independencies which hold for all probability functions on a unary language satisfying the Principle of Atom Exchangeability. We then show that if this is strengthen to the requirement that Johnson's Sufficientness Principle holds, thus giving Carnap's Continuum of inductive methods for languages with at least two predicates, then new and somewhat inexplicable identities and independencies emerge, the latter even in the case of Carnap's Continuum for the language with just a single predicate.

The influential proposal that the analytical component of a theory is captured by its ‘Carnap sentence’ is critically scrutinized. A counterexample which makes the suggestion problematic is presented.