Definitional and axiomatic theories of truth -- Objects of truth -- Tarski -- Truth and set theory -- Technical preliminaries -- Comparing axiomatic theories of truth -- Disquotation -- Classical compositional truth -- Hierarchies -- Typed and type-free theories of truth -- Reasons against typing -- Axioms and rules -- Axioms for type-free truth -- Classical symmetric truth -- Kripke-Feferman -- Axiomatizing Kripke's theory in partial logic -- Grounded truth -- Alternative evaluation schemata -- Disquotation -- Classical logic -- Deflationism (...) -- Reflection -- Ontological reduction -- Applying theories of truth. (shrink)

According to the disquotationalist theory of truth, the Tarskian equivalences, conceived as axioms, yield all there is to say about truth. Several authors have claimed that the expression of infinite conjunctions and disjunctions is the only purpose of the disquotationalist truth predicate. The way in which infinite conjunctions can be expressed by an axiomatized truth predicate is explored and it is considered whether the disquotationalist truth predicate is adequate for this purpose.

At the centre of the traditional discussion of truth is the question of how truth is defined. Recent research, especially with the development of deflationist accounts of truth, has tended to take truth as an undefined primitive notion governed by axioms, while the liar paradox and cognate paradoxes pose problems for certain seemingly natural axioms for truth. In this book, Volker Halbach examines the most important axiomatizations of truth, explores their properties and shows how the logical results impinge on (...) the philosophical topics related to truth. In particular, he shows that the discussion on topics such as deflationism about truth depends on the solution of the paradoxes. His book is an invaluable survey of the logical background to the philosophical discussion of truth, and will be indispensable reading for any graduate or professional philosopher in theories of truth. (shrink)

This paper aims to provide a comprehensive explanation for the likely failure in the decoupling of economic growth from environmental degradation, and also intends to offer perspectives on the new role of competition in a steady state or a degrowth economy. The analysis is based on five different scenarios, and uses the European Union as an example. It is concluded that we must prepare ourselves for a potential incompatibility between sustainability and economic growth. In this respect one can say that (...) the current EU situation is in some ways already quite close to an economic system without growth, although far from sustainable as yet. Two of the four perspectives developed, regarding the new role of competition in an economy without growth, indicate an increase of direct and indirect competition over resources. The other two perspectives point out that regulatory public intervention as well as financial intervention will increase in order to ensure that - despite the revised role of competition - the poorest are still given a chance to develop (e.g. through basic minimum incomes), even in a degrowth economy. (shrink)

We investigate axiomatizations of Kripke's theory of truth based on the Strong Kleene evaluation scheme for treating sentences lacking a truth value. Feferman's axiomatization KF formulated in classical logic is an indirect approach, because it is not sound with respect to Kripke's semantics in the straightforward sense: only the sentences that can be proved to be true in KF are valid in Kripke's partial models. Reinhardt proposed to focus just on the sentences that can be proved to be true in (...) KF and conjectured that the detour through classical logic in KF is dispensable. We refute Reinhardt's Conjecture, and provide a direct axiomatization PKF of Kripke's theory in partial logic. We argue that any natural axiomatization of Kripke's theory in Strong Kleene logic has the same proof-theoretic strength as PKF, namely the strength of the system RA< ωω ramified analysis or a system of Tarskian ramified truth up to ωω. Thus any such axiomatization is much weaker than Feferman's axiomatization KF in classical logic, which is equivalent to the system RA<ε₀ of ramified analysis up to ε₀. (shrink)

Disquotational theories of truth, that is, theories of truth based on the T-sentences or similar equivalences as axioms are often thought to be deductively weak. This view is correct if the truth predicate is allowed to apply only to sentences not containing the truth predicate. By taking a slightly more liberal approach toward the paradoxes, I obtain a disquotational theory of truth that is proof theoretically as strong as compositional theories such as the Kripket probe the compositional axioms.

This contribution attempts to define the relation between phenomenology and philosophy of practice by considering their respective conceptions of philosophy and especially the consequences of modern critiques of metaphysics. The two characteristic perspectives of performative metaphysics and of meaning analysis are used for further critical inquiry into the standpoints of phenomenology and philosophy of practice. As a conclusion, this inquiry is continued in a common area of interest of both standpoints, that is, the relation between personality and embodied being.

On the one hand, the concept of truth is a major research subject in analytic philosophy. On the other hand, mathematical logicians have developed sophisticated logical theories of truth and the paradoxes. Recent developments in logical theories of the semantical paradoxes are highly relevant for philosophical research on the notion of truth. And conversely, philosophical guidance is necessary for the development of logical theories of truth and the paradoxes. From this perspective, this volume intends to reflect and promote deeper interaction (...) and collaboration between philosophers and logicians investigating the concept of truth than has existed so far.Aside from an extended introductory overview of recent work in the theory of truth, the volume consists of articles by leading philosophers and logicians on subjects and debates that are situated on the interface between logical and philosophical theories of truth. The volume is intended for graduate students in philosophy and in logic who want an introduction to contemporary research in this area, as well as for professional philosophers and logicians. (shrink)

The uniform reflection principle for the theory of uniform T-sentences is added to PA. The resulting system is justified on the basis of a disquotationalist theory of truth where the provability predicate is conceived as a special kind of analyticity. The system is equivalent to the system ACA of arithmetical comprehension. If the truth predicate is also allowed to occur in the sentences that are inserted in the T-sentences, yet not in the scope of negation, the system with the reflection (...) schema for these T-sentences assumes the strength of the Kripke-Feferman theory KF, and thus of ramified analysis up to go. (shrink)

A theory of the transfinite Tarskian hierarchy of languages is outlined and compared to a notion of partial truth by Kripke. It is shown that the hierarchy can be embedded into Kripke's minimal fixed point model. From this results on the expressive power of both approaches are obtained.

Wittgenstein’s Whewell’s Court Lectures contains previously unpublished notes from lectures given by Ludwig Wittgenstein between 1938 and 1941. The volume offers new insight into the development of Wittgenstein’s thought and includes some of the finest examples of Wittgenstein’s lectures in regard to both content and reliability.

The general notions of object- and metalanguage are discussed and as a special case of this relation an arbitrary first order language with an infinite model is expanded by a predicate symbol T0 which is interpreted as truth predicate for . Then the expanded language is again augmented by a new truth predicate T1 for the whole language plus T0. This process is iterated into the transfinite to obtain the Tarskian hierarchy of languages. It is shown that there are natural (...) points for stopping this process. The sets which become definable in suitable hierarchies are investigated, so that the relevance of the Tarskian hierarchy to some subjects of philosophy of mathematics are clarified. (shrink)

To the axioms of Peano arithmetic formulated in a language with an additional unary predicate symbol T we add the rules of necessitation and conecessitation T and axioms stating that T commutes with the logical connectives and quantifiers. By a result of McGee this theory is -inconsistent, but it can be approximated by models obtained by a kind of rule-of-revision semantics. Furthermore we prove that FS is equivalent to a system already studied by Friedman and Sheard and give an analysis (...) of its proof theory. (shrink)

This article critically engages a recent essay Jeffrey Alexander has published on ‘societalization’, whose conceptualization it finds problematic; first, because in contrast to the impression conveyed by the essay, the term itself is anything but new (as shown in a summary of six theories of societalization which precede Alexander’s by decades, in two cases, by more than a century), and, second, because the way Alexander employs the term is highly aporetic, while also being emblematic of much deeper problems that afflict (...) the whole discipline. Following a reconstruction of the term’s morphology and the transmutations it underwent during its gradual incorporation into the English language, the article identifies an undertheorized concept of society as the root cause behind the difficulties into which Alexander maneuvers himself. It concludes with a brief sketch of an alternative that can contribute to overcoming these difficulties. (shrink)

Against competing political theories of the integration of immigrants, we propose to reframe the relationship between the populations of host countries and arriving refugees in terms of a neo-Maussian theory of gift exchange. Using the example of the European refugee crisis of 2015 and the welcoming attitude of significant parts of German civil society, we argue that this particular situation should be understood as epitomizing the trend toward internal transnationalism. Increasingly, the “international” is becoming part and parcel of the “domestic” (...) sphere. Since Marcel Mauss was concerned with the question of how separate, culturally different communities can establish ties of solidarity and cooperation between each other, we use his work to answer key questions about the relations between international refugees and native citizens in their home countries: What are the expectations underlying gift-giving in the context of welcoming refugees? Should refugees feel obliged to repay the arrival gifts? How sh... (shrink)

Name der Zeitschrift: Das Mittelalter Jahrgang: 19 Heft: 1 Seiten: 125-145.

If we read Hegel′s “phenomenology” not as a historical product of the intention of an author, but as an expression of the process of creative experience, whose autonomous “negativity” changes every intention of objectual cognition, then the fundamental problems of its “systematic” pretention emerges in a new manner. Creative processes possess an unconditional, incalculable dimension of time, which cannot be reduced to the progressive growth of experience theoretically mediated and controlled. Guided by this understanding, the essay develops the problem of (...) the temporality of the “selfmovement” of the “speculative concept” and its unavailable “negativity”, interpreting it as the logic of creative development which removes itself from the calculation by way of presupposed distinctions. (shrink)

Over the past decades, we have witnessed calls for greater transdisciplinary engagement between scientific and societal actors to develop more robust answers to complex societal challenges. Although there seems to be agreement that these approaches might nurture innovations of a new kind, we know little regarding the research practices, their potential, and the limitations. To fill this gap, this article investigates a funding scheme in the area of transdisciplinary sustainability research. It offers a detailed analysis of the imaginaries and expectations (...) on which the funding scheme rests and how researchers actually practice transdisciplinarity within the respective projects. Identifying three ideal typical models of science–society relations at work, attention is paid to how, where, and when societal and scientific arenas get entangled. This article discusses the tensions between classical academic values and efforts to open research to society, the prevailing power structures that make societal participation challenging, the importance of place and technopolitical cultures, and how temporal project structures impede more radical openings to new ways of knowledge production. We finally emphasize that transdisciplinary knowledge production can only become a serious option for addressing societal challenges if broader changes are made to the knowledge regimes in place. (shrink)

This paper gives a survey of David Hilbert's (1862–1943) changing attitudes towards logic. The logical theory of the Göttingen mathematician is presented as intimately linked to his studies on the foundation of mathematics. Hilbert developed his logical theory in three stages: (1) in his early axiomatic programme until 1903 Hilbert proposed to use the traditional theory of logical inferences to prove the consistency of his set of axioms for arithmetic. (2) After the publication of the logical and set-theoretical paradoxes by (...) Gottlob Frege and Bertrand Russell it was due to Hilbert and his closest collaborator Ernst Zermelo that mathematical logic became one of the topics taught in courses for Göttingen mathematics students. The axiomatization of logic and set-theory became part of the axiomatic programme, and they tried to create their own consistent logical calculi as tools for proving consistency of axiomatic systems. (3) In his struggle with intuitionism, represented by L. E. J. Brouwer and his advocate Hermann Weyl, Hilbert, assisted by Paul Bemays, created the distinction between proper mathematics and meta-mathematics, the latter using only finite means. He considerably revised the logical calculus of thePrincipia Mathematica of Alfred North Whitehead and Bertrand Russell by introducing the ε-axiom which should serve for avoiding infinite operations in logic. (shrink)

Solutions to semantic paradoxes often involve restrictions of classical logic for semantic vocabulary. In the paper we investigate the costs of these restrictions in a model case. In particular, we fix two systems of truth capturing the same conception of truth: of the system KF of Feferman formulated in classical logic, and the system PKF of Halbach and Horsten, formulated in basic De Morgan logic. The classical system is known to be much stronger than the nonclassical one. We assess the (...) reasons for this asymmetry by showing that the truth theoretic principles of PKF cannot be blamed: PKF with induction restricted to non-semantic vocabulary coincides in fact with what the restricted version of KF proves true. (shrink)

This article suggests reading Theodor Adorno not as a notoriously pessimistic sociologist but as a committed public educator. Partly drawing on still unpublished transcripts of lectures, public talks and radio broadcasts from the 1950s and ’60s, the article offers an account of Adorno’s concept and practice of a ‘democratic pedagogy’. The key question is how we should understand the difference between Adorno the social philosopher, on the one hand, and Adorno the educator, on the other. It is argued that Adorno’s (...) pedagogical interventions are not a footnote to his social theory, but a key to understanding his entire oeuvre. (shrink)

In this sequel toSelf-reference in arithmetic Iwe continue our discussion of the question: What does it mean for a sentence of arithmetic to ascribe to itself a property? We investigate how the properties of the supposedly self-referential sentences depend on the chosen coding, the formulae expressing the properties and the way a fixed point for the expressing formulae are obtained. In this second part we look at some further examples. In particular, we study sentences apparently expressing their Rosser-provability, their own${\rm{\Sigma (...) }}_n^0$-truth or their own${\rm{\Pi }}_n^0$-truth. Finally we offer an assessment of the results of both papers. (shrink)

This paper presents the history of the first German lectureship for mathematical logic based on a ministerial commission, to which the Göttingen mathematician Ernst Zermelo was appointed in 1907. The lectureship is shown as imbedded in the intellectual history of mathematical logic which was at that time determined by the discussion of the set theoretical and logical paradoxes. Although Zermelo's early set theoretic papers can be regarded, and were in fact regarded in the Göttingen mathematicians' application for the lectureship, as (...) contributions to mathematical logic, the close connection between set theory and logic was at that time not evident. It is shown, however, that such “internal” motives were not the only reasons for proposing the lectureship, since the application was also highly influenced by personal and institutional factors and the attempt to find a paid position for Zermelo at the University of Göttingen. In addition, Zermelo's lectureship is presented in the context of the history of academic teaching in mathematical and symbolic logic with an overview of German lecture courses in this topic in the period between 1830 and 1915. The results are correlated with the reception of George Boole's algebra of logic and other symbolic logical systems in Germany at that time. Zermelo's lectureship is regarded as the first step towards an institutionalization of mathematical logic as a subdiscipline of mathematics. This step is interpreted by critically applying the results of Hubert Laitko's and Martin Guntau's considerations on the genesis of scientific disciplines. (shrink)

As show the partly violent clashes between liberal secularists and Islamists in the aftermath of the Arab Spring, the two factions certainly defend two diametrically opposite political points of view. For liberals, politics finds its ultimate justification in the protection of individual freedom. For Islamists, only the application of the moral code and religious law codified in the shariah can justify politics. Contrary to what is sustained by a theory of situated agency, there is no easy and definite reconciliation between (...) the two positions. And this depends precisely upon the fact that both political models are based upon the very same idealist conception of the individual, namely the assumption that we, as persons, have a free will and are not determined by the law of causality. Paradoxical as it might sound, it is our freedom that gives rise to the problem of identity and lends force to the Islamist argumentation. If freedom as such cannot bring about practical reason and also liberals recognize that the ultimate source of normativity is identity, there is a point in the Islamist and, more general, communitarian claim that we are not free to choose our identity. In order that identity does the normative work it is supposed to do, it must be given and not chosen. What remains, however, unclear in the communitarian picture is how the norms of our community can come to constitute our will without a process of active identification. If we cannot identify voluntarily with our community’s norms, then only emotional attachment to our community can explain identification and the normative grip communitarian norms have upon us. Yet, attachment is conditioned by the effective satisfaction of our psychological and physical needs. The problem is that our need for freedom and liberty can become overshadowed by our more immediate needs based, for example, upon resentment and revenge and that today makes Muslims in particular to be so hostile towards liberal ideas. I suggest that conciliatory trust-building measures can help to surmount the anger, fear, mistrust and suspicion Muslims feel vis-à-vis the West and that are at the origin of today’s conflict between freedom and identity in the Muslim world. (shrink)

Summary The non-statement view of scientific theories contains a new conception of theoreticity: A function is „T-theoretical if T must be presupposed for its calculation. On the basis of this conception some philosophers came to the conclusion that scientific theories are not empirically testable because they contain T-theoretical functions. It is claimed that the attempt to test them ends in a circularity: The test of T presupposes T itself.

The history of modern logic is usually written as the history of mathematical or, more general, symbolic logic. As such it was created by mathematicians. Not regarding its anticipations in Scholastic logic and in the rationalistic era, its continuous development began with George Boole's The Mathematical Analysis of Logic of 1847, and it became a mathematical subdiscipline in the early 20th century. This style of presentation cuts off one eminent line of development, the philosophical development of logic, although logic is (...) evidently one of the basic disciplines of philosophy. One needs only to recall some of the standard 19th century definitions of logic as, e.g., the art and science of reasoning (Whateley) or as giving the normative rules of correct reasoning (Herbart). In the paper the relationship between the philosophical and the mathematical development of logic will be discussed. Answers to the following questions will be provided: 1. What were the reasons for the philosophers' lack of interest in formal logic? 2. What were the reasons for the mathematicians' interest in logic? 3. What did "logic reform" mean in the 19th century? Were the systems of mathematical logic initially regarded as contributions to a reform of logic? 4. Was mathematical logic regarded as art, as science or as both? (shrink)