The genetically and experimentally accessible organs of Drosophila, such as the heart or blood‐forming tissues, have become a fertile ground for systematic projects of gene discovery and for functional studies of gene networks and signaling pathways. One argument justifying this approach is the often‐tacit assumption that clear‐cut homologies can be established between the Drosophila organs and their vertebrate counterparts. Here we investigate this assumption by surveying pertinent aspects of vascular structure and development in different invertebrate phyla, in the hope that (...) this information will help to reveal the ancestral condition of the vascular system. Evolutionary scenarios that derive the structure of the cardiovascular system of extant animal taxa from the ancestral condition will be used to qualify hypotheses regarding homologies that are based on molecular similarities. BioEssays 28: 1203–1210, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

The acoel worm Symsagittifera roscoffensis, an early offshoot of the Bilateria and the only well‐studied marine acoel that lives in a photosymbiotic relationship, exhibits a centralized nervous system, brain regeneration, and a wide repertoire of complex behaviors such as circatidal rhythmicity, photo/geotaxis, and social interactions. While this animal can be collected by the thousands and is studied historically, significant progress is made over the last decade to develop it as an emerging marine model. The authors here present the feasibility of (...) culturing it in the laboratory and describe the progress made on different areas, including genomic and tissue architectures, highlighting the associated challenges. In light of these developments, and on the ability to access abundant synchronized embryos, the authors put forward S. roscoffensis as a marine system to revisit questions in the areas of photosymbiosis, regeneration, chronobiology, and the study of complex behaviors from a molecular and evolutionary perspective. (shrink)

We show that in the Maxwell–Lorentz theory of classical electrodynamics most initial values for fields and particles lead to an ill-defined dynamics, as they exhibit singularities or discontinuities along light-cones. This phenomenon suggests that the Maxwell equations and the Lorentz force law ought rather to be read as a system of delay differential equations, that is, differential equations that relate a function and its derivatives at different times. This mathematical reformulation, however, leads to physical and philosophical consequences for the ontological (...) status of the electromagnetic field. In particular, fields cannot be taken as independent degrees of freedom, which suggests that one should not add them to the ontology. (shrink)

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)

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)

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)

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)

Die Thematik des Großen durchzieht Nietzsches gesamtes Werk. Sowohl adjektivisch als "Große Vernunft", "Große Gesundheit", "Große Politik" oder "Großer Mittag" wird sie problematisiert, wie sie auch enthalten ist in Metaphern wie der "ewigen Wiederkehr des Gleichen", des "Übermenschen", des "Willen zur Macht", der "Pfeile der Sehnsucht" oder des ereignishaft einschlagenden "Blitzes". Für Nietzsche gibt es keine Größe ohne den Sinn für das Kleine, die Kritik am Kleinen deutet auf kommende Größe. Die Beiträge dieses Bandes widmen sich dem Komplex Nietzsche/Macht/Größe aus (...) philosophischen, politischen, historischen, ästhetischen und kulturwissenschaftlichen Perspektiven. (shrink)

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

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)

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...

Hauptbeschreibung Hinter den Anderen erscheint unser Ich immer schon als Schattenbild aller Möglichkeiten Seit jeher ist sich der Mensch in seiner Bösartigkeit und Güte ein Rätsel, dem Philosophen mit Moral und Tugend beizukommen versucht haben. Dabei ist der scharfe Blick auf das tatsächliche Verhalten von Menschen nicht verlorengegangen. Die Aufklärung am Beginn unserer Moderne versuchte eine Balance zwischen einem realistischen Menschenbild und einer zukunftsweisenden Perspektive zu finden, die das Zusammenleben durch Staat und Recht für alle verträglich machen sollte. D.

A substitutional account of logical validity for formal first‐order languages is developed and defended against competing accounts such as the model‐theoretic definition of validity. Roughly, a substitution instance of a sentence is defined as the result of uniformly substituting nonlogical expressions in the sentence with expressions of the same grammatical category and possibly relativizing quantifiers. In particular, predicate symbols can be replaced with formulae possibly containing additional free variables. A sentence is defined to be logically true iff all its substitution (...) instances are satisfied by all variable assignments. Logical consequence is defined analogously. Satisfaction is taken to be a primitive notion and axiomatized.For every set‐theoretic model in the sense of model theory there exists a corresponding substitutional interpretation in a sense to be specified. Conversely, however, there are substitutional interpretations – in particular the ‘intended’ interpretation – that lack a model‐theoretic counterpart. The substitutional definition of logical validity overcomes the weaknesses of more restrictive accounts of substitutional validity; unlike model‐theoretic logical consequence, the substitutional notion is trivially and provably truth preserving. In Kreisel's squeezing argument the formal notion of substitutional validity naturally slots into the place of intuitive validity. (shrink)

Today we can identify two challenges of pluralism: the ever-growing conflicts between religious, national and ethnic groups on the one hand and the oppression of dissenting individuals by their respective communities on the other hand. Both intercommunitarian and intracommunitarian conflicts find their origin in a communitarian conception of our political, cultural, or religious identities. After presenting some of the problems of the communitarian solution in particular with regard to the challenge of internal pluralism, I introduce alternative conceptions of multiculturalism that (...) consider our commitments to be part of our personal or individual identity. Distinguishing a conception of identity based upon self-knowledge from liberal, postmodern theories (Richard Rorty) and alternative non-cognitive theories (Bernard Williams) that consider identity to be individual in nature, I propose that the awareness of the individual nature of commitments makes it possible for us not to impose our values upon other individuals who do not share them while at the same time justifying the multicultural project. (shrink)

This introduction discusses articles on the theory and politics of republicanism that were presented at the Istanbul Seminars 2015. It asks the following questions: Could it be that republicanism is at least in part the cause of the current cultural clashes and religious violence in both the Arab world and Europe?. Is it just an accident that republics in many parts of the post-colonial world turned authoritarian? Or does republicanism as such risk resulting in illiberal outcomes? In this regard, it (...) analyses, first, if there is a tension or inherent contradiction between republicanism and Islam. Second, this article examines if the political models in Turkey and France are misconceptions of republicanism and the republican ideal of freedom as non-domination. Last but not least, it raises the question if deliberative democracy is the best possible interpretation of republicanism, able to accommodate both freedom as non-domination and pluralism. (shrink)

The article presents different theories and comparative analyses of freedom of speech in both liberal and non-liberal traditions. Whereas freedom of speech is not an absolute right, the question is if this right should depend wholly on the truth of the respective opinion or statement. Theories that justify free speech on the grounds of autonomy, tend to make truth a moral requirement of speech. Theories based on civility and public reason do restrict freedom of speech even further, often making a (...) form of recognition a precondition of free speech. This reveals to be particularly relevant in multicultural contexts and discussions about blasphemy. From this overview of contemporary, global comparative debates on free speech, the article draws some conclusions. First, there should be the absolute primacy of free speech regarding governments and the powerful: Speak truth to power. Second, free speech should underlie no constraints where important individual rights are at stake. Third, academic freedom has a special status and should not be subject to the same limits as freedom of expression more generally. Forth, in civil society and the public sphere a more moderate approach to free speech should be adopted based on civility, public reason and recognition. Yet, any limits should be of moral and not legal nature. (shrink)

English summary: From an international and interdisciplinary viewpoint, Thomas Aquinas was the most important scholastic philosopher and theologian. His life, work and legacy are set out in this four section handbook which provides orientation in what is currently known about the man, his affinities and character, his work and its impact. The volume offers a summary of research up until now, as well as a basis for further investigation. Comprehensive indexes and literature sources mean it can be used as a (...) work of reference whose articles can be separately or integrally understood. Writing from their different perspectives, philosophy and history scholars along with Protestant and Catholic theologians all help paint this portrait from their different perspectives. German description: Das Thomas Handbuch bietet eine Darstellung von Leben, Werk und Wirkung von Thomas von Aquin, dem wohl bedeutendsten Vertreter der scholastischen Philosophie und Theologie in interdisziplinarer und internationaler Perspektive. In vier Sektionen enthalt es Ausfuhrungen zur Orientierung in der gegenwartigen Forschungslage, zur Person des Thomas und ihren Verbindungen und Pragungen, zu seinem Werk und zu seiner Wirkung. Es bietet eine Zusammenfassung der bisherigen Forschungen zu Thomas von Aquin und eine Grundlage fur weitere Arbeiten. Erschlossen durch umfassende Register und Literaturangaben, kann es als Nachschlagewerk genutzt werden, dessen einzelne Artikel je fur sich verstehbar sind, aber auch als umfassende Gesamtdarstellung. Die interdisziplinaren Beitrage eroffnen eine Gesamtschau, in welcher verschiedene Perspektiven ihren Ort finden und ihren je eigenen Beitrag zum Gesamten bieten. Mit Beitragen von: Henryk Anzulewicz, Carmela Baffioni, Michael Basse, David Berger, Inos Biffi, Volker Henning Drecoll, Mechthild Dreyer, Stephan Ernst, Sabine Folger-Fonfara, Elias Fullenbach, Ruedi Imbach, Ingo Klitzsch, Ulrich Kopf, Pieter de Leemans, Volker Leppin, Jurgen Miethke, Thomas Prugl, Francois-Xavier Putallaz, Reinhold Rieger, Philipp W. Rosemann, Marianne Schlosser, Gury Schneider-Ludorff, Rolf Schonberger, Christoph Schwobel, Notger Slenczka, Wolfgang Sturner, Hubert Philip Weber. (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)

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 paper deals with a problem which has received a great deal of attention in the ethical literature, but about which very little is known empirically: the selection of recipients for organs in transplant medicine. Based on a larger study, it is shown how this problem is practically resolved in one European country, Germany. It is demonstrated that most of the criteria used to determine recipients are non-medical in nature, even though they generally tend to be rationalized in medical terms. (...) Moreover, the choice of criteria depends as much on prognostic considerations as on personal indiosyncrasies and values held by individual physicians who are in charge at the various programs. Several examples of the extremely diverse policies in which this results are presented. (shrink)