Free-variable semantic tableaux are a well-established technique for first-order theorem proving where free variables act as a meta-linguistic device for tracking the eigenvariables used during proof search. We present the theoretical foundations to extend this technique to propositional modal logics, including non-trivial rigorous proofs of soundness and completeness, and also present various techniques that improve the efficiency of the basic naive method for such tableaux.

This note on my exchange with G. Kirchgässner points to a possible misunderstanding and one serious difference of opinion. On the empirical side I tried to make visible social values and norms which cannot be reduced to economic preferences. On the normative side I tried to criticise the rational-choice-approach for being either obviously wrong or empirically empty.

While markets are important mechanisms for coordination of social exchange it has to be looked at their limits and preconditions as well. This paper advocates three claims: First, under conditions of externalities and asymmetric distribution of information the eflicient functioning of markets depends on non-market institutions. Second, social limitations of the expansion of markets reflect a value-realm in which society constitutes itself. These values, though they change, are normatively immune against efficiency consideration. Third, the rational-actor model of economics is insufficient (...) for the understanding of the non-rational preconditions of markets and the embeddedness of markets in social values. (shrink)

O presente trabalho procura equacionar os dilemas com que uma disciplina tão recente como a Ética Ambiental se confronta, quando estabelece critérios de avaliação da natureza em termos do seu valor intrinseco. Para tal, recorreu-se a um caso hipotético, onde conflituam interesses de diversas entidades naturais, de modo a mostrar as diferentes soluções avançadas para o conflito, conforme se atribui valor moral aos seres sencientes (ética animal), a toda a manifestação de vida (etica biocêntrica) ou à própria natureza como totalidade (...) sistemica (ética ecocêntrica). /// This paper tries to equate the dilemmas arisen in such a recent subject as Environmental Ethics when it defines criteria to evaluate nature in terms of its intrinsic value. An hypothetical case was chosen where interests of different natural entities are in conflict, so that several solutions can be presented depending on moral value being conferred to sentient beings (animal ethic), to all forms of life (biocentric ethic), or to nature itself as a systemic whole (ecocentric ethic). (shrink)

Good’s theorem is the apparent platitude that it is always rational to ‘look before you leap’: to gather information before making a decision when doing so is free. We argue that Good’s theorem is not platitudinous and may be false. And we argue that the correct advice is rather to ‘make your act depend on the answer to a question’. Looking before you leap is rational when, but only when, it is a way to do this.

Epistemologists have recently noted a tension between (i) denying access internalism, and (ii) maintaining that rational agents cannot be epistemically akratic, believing claims akin to ‘p, but I shouldn’t believe p’. I bring out the tension, and develop a new way to resolve it. The basic strategy is to say that access internalism is false, but that counterexamples to it are ‘elusive’ in a way that prevents rational agents from suspecting that they themselves are counterexamples to the internalist principles. I (...) argue that this allows us to do justice to the motivations behind both (i) and (ii). And I explain in some detail what a view of evidence that implements this strategy, and makes it independently plausible, might look like. (shrink)

Without directly addressing the Demarcation Problem for logic—the problem of distinguishing logical vocabulary from others—we focus on distinctive aspects of logical vocabulary in pursuit of a second goal in the philosophy of logic, namely, proposing criteria for the justification of logical rules. Our preferred approach has three components. Two of these are effectively Belnap’s, but with a twist. We agree with Belnap’s response to Prior’s challenge to inferentialist characterisations of the meanings of logical constants. Belnap argued that for a logical (...) constant to exist, its rules must be conservative over a previously given consequence relation and guarantee the uniqueness of the constant. The twist is that we require logical vocabulary to be provably conservative, not over a previously given formal consequence relation, but over a previously given meaningful vocabulary of a language. Uniqueness is also a feature defined in terms of provability: if two syntactically distinguished expressions are governed by the same rules, then formulas with them as main operators are interderivable. Belnap’s criteria are not only those for the existence of a logical constant, but more: they are what distinguishes logical vocabulary from all other expressions. It is the defining mark of a logical constant that it is provably conservative over the fragment of the language which excludes it and that its rules guarantee its uniqueness. The third component is the topic neutrality of logic. The provable conservativeness of logic over a previously given vocabulary of a language is motivated, in part, by appeal to molecularism in the theory of meaning. Molecularity is a feature endorsed by the theory of meaning as a whole, so it does not distinguish logical constants from other expressions. The same is true for conservativeness. We argue that molecularity, and hence conservativeness, are implicit presuppositions of speakers’ use of language: the addition of new vocabulary to a language is presupposed to be conservative. But this presupposition is one that we should be able reflectively to endorse (such as when attempting a rational reconstruction of the use of the vocabulary). Thus, where conservativeness is found to fail, this defect should be remedied and the use of the vocabulary corrected (as in classical negation) or excised altogether (as in pejoratives). We go on to characterise a notion of topic neutrality, which we argue applies to logical vocabulary. We then note that reflective endorsement of the conservativeness of a topic neutral vocabulary requires a proof that the vocabulary is conservative relative to any base vocabulary. Thus we require that logical vocabulary be demonstrably conservative. Allying this requirement, distinctive of logic, to a general consideration about the commitments of assertion yields a mode of justification for logical constants akin to some conceptions of Harmony, i.e., to the idea that the consequences of assertion of a logical complex need to be warranted by the grounds and ought to be the strongest consequences warranted by the grounds. Intuitionistic logic acquires a somewhat familiar justification but emanating from a new motivation. (shrink)

Bernhard Nickel presents a theory of generic sentences and the kind-directed modes of thought they express. The theory closely integrates compositional semantics with metaphysics to solve the problem that generics pose: what do generics mean? Generic sentences are extremely simple, yet if there are patterns to be discerned in terms of which are true and which are false, these patterns are subtle and complex. Ravens are black, and lions have manes: statistical measures cannot do justice to the facts, but (...) what else is there that has a hope of giving us insight into what we are capturing across so many domains? Nickel argues that generics are the top of a fundamentally explanatory iceberg, and that this explanatory framework is deeply intertwined with the semantics of the language we use to express them. In providing an integrated semantic and metaphysical theory of generics, he aims to solve old puzzles and draw attention to new phenomena. (shrink)

In der vorliegenden Schrift soll Martin Buber als dem scharfen Diagnostiker unserer Zeit und dem Künder ewiger Wahrheiten die ganze Aufmerksamkeit gelten. Kein Denken lässt sich so wenig in billigen Schlagwörtern einfangen, wie das Martin Bubers. Die erste Aufgabe wird sein, die Situation in der wir leben, und die Buber meint, etwas näher zu bestimmen. Dies wird uns in die Lage setzen, jene Fragen zu vernehmen, die die Situation zu uns allen spricht. Sodann werden wir uns der besonderen Gestalt der (...) Buberschen Antwort zuwenden. Erst dann erscheint die Frage nach Herkunft und Inhalt der Antwort sinnvoll. In einem letzten Teil sollen dann gleichsam drei Bewährungsproben von Bubers Denken erörtert werden. (shrink)

This chapter covers the traditional role of responsibility, and the possible connections between response and responsibility. These connections are explored through the advance of trust and the surplus of the extraordinary in relation to the Third Party. The idea of responsibility comes from the sphere of juridical law, and has a theological touch. The classical conception presented suffers from a permanent erosion that is reinforced by systemic constraints. Trust is a natural element of every community that is together applied by (...) common aims in life. The phenomenon of trust refers to the bond, the nexus, which holds together the members of a community, creating the requisite solidarity. The term ‘trust’ or ‘confidence’ should not primarily read as a substantive, but as a verb or as the derivative of a verb. Furthermore, it is noted that the responsive ethics proposed could function as a permanent corrective. (shrink)

This comment deals with some basic elements Searle uses in order to construct social reality, i.e. togetherness, we-intentionality and the distinction between institutional and brute facts. The commentator argues that Searle’s theory tends to a partial biologism because lacking a sufficient concept of embodiment. Consequently ‘pre-institutional facts’ such as eating, copulating, working or torturing are systematically underdetermined. On the deontic level the theory relies on natural processes of conventional power. So the distinction between factual acceptance and acceptability is blurred by (...) a sort of conformism, and one neglects the status of dissidents and victims whose belonging to the predominant ‘we’ remains highly dubious. (shrink)

Der orientalische Gott Eros ist in seinen Ursprungen ein Zerreisser dieser Welt. Er wirft sie aus dem Takt und zerstort ihre Harmonie. Das jedoch war den fruhen griechischen Baumeistern des Abendlandes gar nicht recht. In einem aufregenden Akt wurde der Zerreisser zum Versohner umgedeutet. Besonders anschaulich wird diese Geschichte beim grossen Philosophen Platon. Dort liegen die Wurzeln fur eine erregende Spiritualitat auf der einen und fur die technisch-wissenschaftliche Welteroberung auf der anderen Seite. Mit didaktischem Geschick entfaltet der Autor mit zahlreichen (...) Ausblicken auf kulturgeschichtliche Hintergrunde die faszinierende Denkwelt Platons. Dies erschliesst ein tieferes Verstandnis fur die feurige Leidenschaft des Fortschritts, den wir hassen und lieben, der uns befreit und knechtet, der uns Hoffnung ist und Angst auslost und von dem wir - so scheint es - doch nicht loskommen.". (shrink)

Originally presented as the author's thesis (doctoral - Erlangen) under the title: Logica Epternacensis. Untersuchungen zu einer Echternacher Glossensammlung (saec. XII) und ihren Quellen.

This book develops an empirically informed normative theory of need-based justice, summarizing core findings of the DFG research group FOR2104 “Need-based Justice and Distributive Procedures”. In eleven chapters scholars from the fields of economics, political science, philosophy, psychology, and sociology cover the identification and rationale of needs, the recognition and legitimacy of needs, the dynamics and stability of procedures of distributions according to needs, and the consequences and sustainability of need-based distributions. These four areas are studied from the perspective of (...) two mechanisms of need objectification, the social objectification by the discursive generation of mutual understanding (transparency) and the factual objectification by the transfer of decisions to uninvolved experts (expertise). The volume addresses academics in the fields of justice research, ethics, political theory, social choice and welfare, framing, individual and group decision making, inequality and redistribution, as well as advanced students in the contributing disciplines. (shrink)

Few would contest the fact that analytical philosophy has dominated philosophical practice in the English speaking world for about the last century. But dispute continues about both its origins and nature; whilst others question its value. Michael Dummett wholly embraced the analytical approach to philosophy, as he conceived of it. For him analytical philosophy marked itself off from its precursors and its alternatives, embodied in the Continental tradition, by taking the linguistic turn. And Frege was unequivocally the first philosopher to (...) take that auspicious turn, which ushered in a new method in philosophy. Henceforth philosophers were to approach the business of analyzing thought via the enterprise of analyzing language. So Dummett is presenting us with both a history lesson and a recommendation about how we ought to do philosophy. But is his reading of the history accurate? And is his conception of the nature of analytical philosophy viable? In order to reflect on these questions this collection brings together eight scholars who have made a serious business of reading Dummett. (shrink)

I argue that a practice can only be taken to be one of apparent rule following if it contains a practice of policing moves within the practice. So the existence of an apparently rule-governed practice entails the existence of, what I call, a policing practice. I then argue that this entailment cannot be reconciled with a non-factualist construal of the policing practice. Thus non-factualism about the policing practice is false. Factualism about the policing practice entails realism about rules. So I (...) conclude that we ought to be realists about rules. Finally I distinguish a position which I call ultra-realism about rules and note that this too is a casualty of the view developed here. (shrink)

Traditional approaches to human information processing tend to deal with perception and action planning in isolation, so that an adequate account of the perception-action interface is still missing. On the perceptual side, the dominant cognitive view largely underestimates, and thus fails to account for, the impact of action-related processes on both the processing of perceptual information and on perceptual learning. On the action side, most approaches conceive of action planning as a mere continuation of stimulus processing, thus failing to account (...) for the goal-directedness of even the simplest reaction in an experimental task. We propose a new framework for a more adequate theoretical treatment of perception and action planning, in which perceptual contents and action plans are coded in a common representational medium by feature codes with distal reference. Perceived events (perceptions) and to-be-produced events (actions) are equally represented by integrated, task-tuned networks of feature codes – cognitive structures we call event codes. We give an overview of evidence from a wide variety of empirical domains, such as spatial stimulus-response compatibility, sensorimotor synchronization, and ideomotor action, showing that our main assumptions are well supported by the data. Key Words: action planning; binding; common coding; event coding; feature integration; perception; perception-action interface. (shrink)