Description logics are a family of knowledge representation formalisms that are descended from semantic networks and frames via the system Kl-one. During the last decade, it has been shown that the important reasoning problems (like subsumption and satisfiability) in a great variety of description logics can be decided using tableau-like algorithms. This is not very surprising since description logics have turned out to be closely related to propositional modal logics and logics of programs (such as propositional dynamic logic), for which (...) tableau procedures have been quite successful.Nevertheless, due to different underlying institutions and applications, most description logics differ significantly from run-of-the-mill modal and program logics. Consequently, the research on tableau algorithms in description logics led to new techniques and results, which are, however, also of interest for modal logicians. In this article, we will focus on three features that play an important rôle in description logics (number restrictions, terminological axioms, and role constructors), and show how they can be taken into account by tableau algorithms. (shrink)

This note is a sequel to Huber. It is shown that obeying a normative principle relating counterfactual conditionals and conditional beliefs, viz. the royal rule, is a necessary and sufficient means to attaining a cognitive end that relates true beliefs in purely factual, non-modal propositions and true beliefs in purely modal propositions. Along the way I will sketch my idealism about alethic or metaphysical modality.

Den 1905 gefaßten Plan einer Gesamtdarstellung der Aristotelischen Lehre brachte Brentano nicht mehr zur Ausführung. Die hier erstmals veröffentlichten Vorarbeiten aus den Jahren 1908 bis 1911 für die Abhandlung »Aristoteles und seine Weltanschauung« bieten einen detaillierten Einblick in das Aristoteles-Bild des späten Brentano.

"Die Fähigkeit zur Freiheit, verstanden als vernünftige Selbstbestimmung, ist nach Hegel grundlegend für unser Denken und Erkennen ebenso wie für unser Wollen und Handeln: Der 'logische Raum der Gründe' ist für Hegel ein 'Reich der Freiheit'. Franz Knappik untersucht, wie Hegel diesen Gedanken in einer umfassenden Theorie entwickelt, die Logik, Metaphysik, Epistemologie und praktische Rationalität behandelt. In Auseinandersetzung mit analytischen Deutungsansätzen und Sachdiskussionen zeigt Knappik die Aktualität und Originalität von Hegels Position auf."--Cover.

Keine ausführliche Beschreibung für "Fermenta cognitionis, Heft 1." verfügbar.

Whiteheads Prozessphilosophie und Piagets genetischer Strukturalismus stellen zwei der originellsten Denkentwurfe unseres Jahrhunderts dar. Beide Ansatze haben Forschungsaktivitaten auf den verschiedensten Gebieten angeregt. Alte Problemstellungen wurden in ihrem Licht transformiert und neue, uberraschende Losungsvorschlage erarbeitet. In diesem Buch wurde der systematische Versuch unternommen, Piagets genetischen Strukturalismus in Whiteheads Prozessphilosophie zu integrieren. Die inhaltlichen Parallelen - bis ins Detail und bis hin zu ansatzimmanenten Problemen - belegen, dass dies gegluckt ist. Whiteheads Prozessphilosophie erweist sich folglich als Hoffnungstrager in einer Zeit mit (...) zunehmend komplexer werdenden Problemen und interdisziplinaren Fragestellungen.". (shrink)

Unification in description logics has been proposed as a novel inference service that can, for example, be used to detect redundancies in ontologies. The inexpressive description logic EL is of particular interest in this context since, on the one hand, several large biomedical ontologies are defined using EL. On the other hand, unification in EL has been shown to be NP-complete and, thus, of considerably lower complexity than unification in other description logics of similarly restricted expressive power. However, EL allows (...) the use of the top concept, which represents the whole interpretation domain, whereas the large medical ontology SNOMED CT makes no use of this feature. Surprisingly, removing the top concept from EL makes the unification problem considerably harder. More precisely, we will show that unification in EL without the top concept is PSPACE-complete. In addition to the decision problem, we also consider the problem of actually computing EL−⊤-unifiers. (shrink)

In judgment aggregation, unlike preference aggregation, not much is known about domain restrictions that guarantee consistent majority outcomes. We introduce several conditions on individual judgments su¢ - cient for consistent majority judgments. Some are based on global orders of propositions or individuals, others on local orders, still others not on orders at all. Some generalize classic social-choice-theoretic domain conditions, others have no counterpart. Our most general condition gen- eralizes Sen’s triplewise value-restriction, itself the most general classic condition. We also prove (...) a new characterization theorem: for a large class of domains, if there exists any aggregation function satisfying some democratic conditions, then majority voting is the unique such function. Taken together, our results provide new support for the robustness of majority rule. (shrink)

Focusing on the recent explosion in the use of bottled water, this article—originally written for my NASTS conference presentation—will examine the rhetoric used by the bottled water industry and home purification system providers to affect the public’s idea of clean, pure, dirty, and polluted water. Bottlers argue that the Food and Drug Administration (FDA) provides better regulation of bottled water than the Environmental Protection Agency (EPA) could ever do for tap water, though the EPA and the FDA use basically the (...) same set of guidelines. The EPA and FDA definitions in terms of concentrations of specific substances are very different from the ideas of muddy or “dirty” water. This article will examine the impact of the public’s perception of good drinking water and the perception that if it is off the shelf, it is cleaner and tastier. (shrink)

In its first part, this paper shows why a recently made attempt to reduce the special theory of relativity to Newtonian kinematics is bound to fail. In the second part, we propose a differentiated notion of incommensurability which enables us to amend the contention that the special theory of relatively and Newtonian kinematics are “incommensurable”.