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)

Historically, blatantly untrue and defamatory conspiracy theories had disastrous consequences for those who were portrayed in them as evil-doers. At the same time, conspiratorial agreements at the expense of the common good between powerful groups in society do exist and have occasionally been uncovered. Against this background, the article describes different ways in which critical theory has looked at conspiracies. First, an attempt is made to show that Max Horkheimer's notes on `rackets' are an ambitious but flawed attempt to theorize (...) conspiracy. It is argued that Horkheimer's theory is imbued by the very conspiracy thinking that he proposed to criticize. Second, the author suggests recovering Franz Neumann's concept of `political alienation' as a more appropriate starting point to think critically about the ethical and epistemological questions raised by conspiracy theories. (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)

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)

It is a commonplace that in the development of modern logic towards its actual shape at least two directions or traditions have to be distinguished. These traditions may be called, following the mo...

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.

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)

Name der Zeitschrift: Zeitschrift für Religionswissenschaft Jahrgang: 25 Heft: 1 Seiten: 6-29.

While classical temporal logics lose track of a state as soon as a temporal operator is applied, several branching-time logics able to repeatedly refer to a state have been introduced in the literature. We study such logics by introducing a new formalism, hybrid branching-time logics, subsuming the other approaches and making the ability to refer to a state more explicit by assigning a name to it. We analyze the expressive power of hybrid branching-time logics and the complexity of their satisfiability (...) problem. As main result, the satisfiability problem for the hybrid versions of several branching-time logics is proved to be 2EXPTIME -complete. To prove the upper bound, the automata-theoretic approach to branching-time logics is extended to hybrid logics. As a result of independent interest, the nonemptiness problem for alternating one-pebble Büchi tree automata is shown to be 2EXPTIME -complete. A common property of the logics studied is that they refer to only one state. This restriction is crucial: The ability to refer to more than one state causes a nonelementary blow-up in complexity. In particular, we prove that satisfiability for NCTL * has nonelementary complexity. (shrink)

The attempts to mitigate the unprecedented health, economic, and social disruptions caused by the COVID-19 pandemic are largely dependent on establishing compliance to behavioral guidelines and rules that reduce the risk of infection. Here, by conducting an online survey that tested participants’ knowledge about the disease and measured demographic, attitudinal, and cognitive variables, we identify predictors of self-reported social distancing and hygiene behavior. To investigate the cognitive processes underlying health-prevention behavior in the pandemic, we co-opted the dual-process model of thinking (...) to measure participants’ propensities for automatic and intuitive thinking vs. controlled and reflective thinking. Self-reports of 17 precautionary behaviors, including regular hand washing, social distancing, and wearing a face mask, served as a dependent measure. The results of hierarchical regressions showed that age, risk-taking propensity, and concern about the pandemic predicted adoption of precautionary behavior. Variance in cognitive processes also predicted precautionary behavior: participants with higher scores for controlled thinking (measured with the Cognitive Reflection Test) reported less adherence to specific guidelines, as did respondents with a poor understanding of the infection and transmission mechanism of the COVID-19 virus. The predictive power of this model was comparable to an approach (Theory of Planned Behavior) based on attitudes to health behavior. Given these results, we propose the inclusion of measures of cognitive reflection and mental model variables in predictive models of compliance, and future studies of precautionary behavior to establish how cognitive variables are linked with people’s information processing and social norms. (shrink)

This article—mainly referring to the situation in Germany—consists of three parts. In a first section the current presence of neurosciences in the public discourse will be described in order to illuminate the background which is relevant for contemporary educational thinking. The prefix ‘neuro-’ is ubiquitous today and therefore concepts like ‘neuropedagogy’ or ‘neurodidactics’ seem to be in the mainstream of modern thinking. In the second part of the article the perspective changes from the public discourse to the disciplinary discourse; a (...) brief excursus into developmental psychiatry, neuropsychology and modern psychoanalysis will be made in order to demonstrate how the results of neuroscientific research are integrated in their theoretical frameworks. These three disciplines have no difficulty in integrating neuroscientific findings because each of them possesses a systematic core composed of ‘native concepts’. In contrast to them, educational theory has much more difficulty with such integration, as will be shown in the third part of the essay. On the one hand, neuroscientific thinking seems to be able to dominate education rather easily and without great resistance, especially in the fields of early childhood education, instruction and learning—mainly by simplifying educational processes and by reducing the complexity of the educational task to a mere ‘relationship problem’. On the other hand, this attraction of neuroscience in education might be understood as the reflection of a theoretical deficit in educational theory itself, with the significance of affect and emotion not receiving proper attention. (shrink)

This chapter discusses the complex conditions for the emergence of 19th-century symbolic logic. The main scope will be on the mathematical motives leading to the interest in logic; the philosophical context will be dealt with only in passing. The main object of study will be the algebra of logic in its British and German versions. Special emphasis will be laid on the systems of George Boole and above all of his German follower Ernst Schröder.

We study operator equations within the Turing machine based framework for computability in analysis. Is there an algorithm that maps pairs to solutions of Tx = u ? Here we consider the case when T is a bounded linear mapping between Hilbert spaces. We are in particular interested in computing the generalized inverse T†u, which is the standard concept of solution in the theory of inverse problems. Typically, T† is discontinuous and hence no computable mapping. However, we will use effective (...) versions of theorems from the theory of regularization to show that the mapping ↦ T†u is computable. We then go on to study the computability of average-case solutions with respect to Gaussian measures which have been considered in information based complexity. Here, T† is considered as an element of an L2-space. We define suitable representations for such spaces and use the results from the first part of the paper to show that ↦ T† is computable. (shrink)

(1984). Goodbye to the School System— Goodbye to the System of Leisure and Recreation? Aspects of the decay of the last dominant mode of socialisation at the levels of meaning and identity[1] Educational Studies: Vol. 10, No. 1, pp. 43-63.

It is shown that David Hilbert's formalistic approach to axiomaticis accompanied by a certain pragmatism that is compatible with aphilosophical, or, so to say, external foundation of mathematics.Hilbert's foundational programme can thus be seen as areconciliation of Pragmatism and Apriorism. This interpretation iselaborated by discussing two recent positions in the philosophy ofmathematics which are or can be related to Hilbert's axiomaticalprogramme and his formalism. In a first step it is argued that thepragmatism of Hilbert's axiomatic contradicts the opinion thatHilbert style (...) axiomatical systems are closed systems, a reproachposed by Carlo Cellucci. In the second section the question isdiscussed whether Hilbert's pragmatism in foundational issuescomes close to an a-philosophical ``naturalism in mathematics'' assuggested by Penelope Maddy. The answer is ``no'', because forHilbert philosophy had its specific tasks in the general projectto found mathematics. This is illuminated in the concludingsection giving further evidence for Hilbert's foundationalapriorism by discussing his ``axiom of the existence of mind'' andrelating it to the ``one and only axiom'' of the German algebraistof logic, Ernst Schröder, postulating the inherence of signs onthe paper. (shrink)

Zermelos Zeit in Göttingen (1897?1910) kann als wissenschaftlich fruchtbarste Periode in seiner Karriere angesehen werden. Gleichwohl stehen bisher Untersuchungen aus. die eine Einbettung von Zermelos Werk in den biographischen und sozialen Kontext ermöglichen Die vorliegende Studie will diese Lücke unter Konzentration auf zwei Gegenstandsbereiche teileweise ausfüllen: (1) den historischen Entstehungskontext von Zermelos ersten Arbeiten über die Grundlagen der Mengenlehre; (2) die Vorgeschichte und näheren Umstände des 1907 an Zermelo verliehenen Lehrauftrages für mathematische Logik und verwandte Gegenstände. mit dem ein erster (...) Schritt zur Institutionalisierung dieses Faches als mathematischer Teildisziplin gemacht wurde. Beides wird in enger Verbindung zur ersten Phase des Hilbertschen Programms zur Grundlegung der Mathematik gesehen. Es wird aber auch gezeigt, daß für die Erteilung des Lehrauftrages neben diesen systematischen und forschungspolitischen Motiven auch persönliche und institutspolitische Rücksichten ausschlaggebend waren. Im Anhang werden Teile eines Briefwechsels zwischen Ernst Zermelo und dem Göttinger Philosophen Leonard Nelson ediert sowie die Anträge der Direktoren des Göttinger mathematisch-physikalischen Seminars auf Erteilung des Lehrauftrags und auf Ernennung Zermelos zum außerordentlichen Professor. Zermelo's Göttingen period (1897?1910) can be regarded as the most fruitful period in his scientific career. Nevertheless, up till now there have been no investigations which enable us to embed his work in its biographical and social contexts. This study tries to partially fill the gap, concentrating on two major themes: (I) the historical context of the development of Zermelo's early work on the foundations of set theory; (2) the prehistory and particulars of his lectureship for mathematical logic and related topics, this lectureship, which he was awarded in 1907, being the first step taken in Germany towards the establishment of this subject as a separate mathematical discipline. Both will be seen in close connection with the first phase of Hilbert's programme of founding mathematics. It is shown, however, that this lectureship was not only created to further the aims of Hilbert's research programme but that personal and institutional motives also played a role. In the appendices, parts of a correspondence between Ernst Zermelo and the Göttingen Philosopher Leonard Nelson are edited, as well as the applications of the directors of the Göttingen Mathematisch-physikalisches Seminar for awarding the lectureship to Zermelo in 1907, and for appointing Zermelo to an extraordinary professorship in 1910. (shrink)

The article introduces to the issue of religion, rights and the public sphere. It analyzes 4 challenges that the conception of the public sphere currently faces: Does there exists a trade-off between the public sphere and a legal regime of civil rights? Does the public sphere really require us to keep the good and religious questions outside of it? To what extent is the public sphere neutral and not rather itself the outcome of a particular and contingent conception of the (...) good? Whatever might be our answers to the questions 1 to 3, does not Islam constitute a special challenge for any conception of the public sphere? The article draws following prudent conclusions: First, rights are somewhat fundamental for a democratic public sphere. Second, a democratic public sphere cannot exclude religion. Third, little indicates that the public sphere is only a western concept. On the contrary, the public sphere has a universal character. Fourth, Islam does not pose any specific challenge to the public sphere, at least no more than the other religions. (shrink)

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)

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.

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)

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)

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)

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)

To the axioms of Peano arithmetic formulated in a language with an additional unary predicate symbol T we add the rules of necessitation φ/Tφ and conecessitation T φ/φ and axioms stating that T commutes with the logical connectives and quantifiers. By a result of McGee this theory is w-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)

We prove Yablo’s paradox without the diagonal lemma or the recursion theorem. Only a disquotation schema and axioms for a serial and transitive ordering are used in the proof. The consequences for the discussion on whether Yablo’s paradox is circular or involves self-reference are evaluated.

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)

The Qing dynasty scholar Liu Yuan (1768-1856) developed a unique system of thought, merging Confucian learning with ideas and practices from Daoism and Buddhism, and was eventually venerated as the founding patriarch of an influential movement combining the characteristics of a scholarly circle and a religious society. Liu Yuan, a native of Sichuan, was an outstanding Confucian scholar whose teachings were commonly referred to as Liumen (Liu School). Assisted by his close disciples, Liu edited a Daoist ritual canon titled Fayan (...) huizuan (Compendium of Ritual Words). Daoist priests affiliated with the Liumen community and using the Fayan huizuan canon in their rituals constituted an independent liturgical branch of Daoism, which is still extant and known under the name of "Fayan tan" (Altar of Ritual Words). Following a comprehensive description of the Liumen tradition, the volume by Volker Olles discusses the compilation history of the Fayan huizuan canon, the lineage of the Fayan tan priests, as well as the temporal framework of their liturgy. The main part of the volume consists of a detailed study of the ritual canon, identifying its textual sources and describing its pantheon, the influence of the Liumen ideology on its texts, as well as the function and performance of its rituals in contemporary religious practice. Furthermore concluding thoughts about the Fayan tan tradition's role in present-day Sichuan constitute the epilogue. By showing how members of the Confucian elite were involved in the evolution of modern Daoism, this study sheds light on hitherto obscure or poorly understood aspects of the intellectual and spiritual culture of Southwest China. (shrink)

The distinction between the contexts of discovery and justification has left a turbulent wake in the philosophy of science. This book recognizes the need to re-open the debate about the nature, development, and significance of the context distinction, about its merits and flaws. The discussion clears the ground for the productive and fruitful integration of these new developments into philosophy of science.

Is a Muslim still a Muslim when he crashes airplanes into the twin towers? Any serious theory of multiculturalism has to deny that Islam could ever come to justify suicide bombing and terrorism. My thesis is that none of the contemporary multicultural theories manages to do so, or at least not without collapsing into a Kantian conception of personal autonomy and, consequently, into some standard version of liberalism. Communitarianism, trying to demonstrate that fundamentalism has nothing to do with the true (...) and authentic Islam and that it does not take into account the pluralism prevailing in Islam, has to moralize Islam. A Humean position, which takes Islamic fundamentalism to be merely a pathology, the product of resentment and western neocolonialism, eventually could come to the conclusion that good and upright Muslims today cannot help but become suicide bombers. Liberal multiculturalism, considering identity to be a matter of choice, must suppose that an active agent with self-knowledge is by definition a responsible person with a moral identity. In conclusion, multiculturalism, in its effort to make the good identities prevail over the bad and the ugly identities, risks adopting some of the same righteous attitudes towards Islam as traditional liberalism. (shrink)

Three recently published reports show to what extent democracy is losing ground in a global context increasingly characterized by authoritarianism and populism. The argument this articles proposes is that the deplorable state of democracies around the world is due to the neglect of substantial characteristics and sources of democracy, which are above all trust and solidarity. Democracy has three different, but interrelated sources that are built upon each other according to a lexical order. A democracy is first based upon political (...) rights, there is in an inherent liberal component to democracy. Second, a democracy requires trust among citizens and individuals that only some form of common identity is going to produce. Third, democracy is based upon strong forms of equality that are brought about by solidarity. The article comes to following conclusions: First, as the experience of Islamophobia and racism in Europe and authoritarianism in the Arab world shows, the concepts of illiberal democracy or majoritarianism currently promoted by strongmen around the globe do not stand for proper democratic political systems. Second, in our plural societies, neither thick nationalism nor strong multiculturalism does support the development of the democratic spirit. Third, Republicanism in Rousseau’s tradition is right that inequalities are the main cause undermining full democracies. A democracy requires the solidarity of the welfare state. (shrink)

Nowadays the question of toleration is less related to an international clash of civilizations than to the clashes that take place within the states and polities themselves. The article addresses the sources of toleration in this new global scenario, starting from the following set of questions: Do the sources of toleration differ across time and space? Does toleration have different roots in different civilizational contexts, such as China, India or Islam? Or, is toleration the result of particular institutional frameworks and (...) designs? In this case, does the concept of toleration vary from one institutional setting to the other? Do empires, republics and democracies give rise to different forms of toleration? And last but not least, isn’t toleration rather a matter of individual morality, as many liberal theories sustain? The article distinguishes between three different sources of toleration: individuals, cultures and institutions. Kant and contemporary liberals, as John Rawls who follows him, situate t... (shrink)