The first introductory textbook on description logics, relevant to computer science, knowledge representation and the semantic web.

In 1984, Danecki proved that satisfiability in IPDL, i.e., Propositional Dynamic Logic (PDL) extended with an intersection operator on programs, is decidable in deterministic double exponential time. Since then, the exact complexity of IPDL has remained an open problem: the best known lower bound was the ExpTime one stemming from plain PDL until, in 2004, the first author established ExpSpace-hardness. In this paper, we finally close the gap and prove that IPDL is hard for 2-ExpTime, thus 2-ExpTime-complete. We then sharpen (...) our lower bound, showing that it even applies to IPDL without the test operator interpreted on tree structures. (shrink)

As a remedy for the bad computational behaviour of first-order temporal logic (FOTL), it has recently been proposed to restrict the application of temporal operators to formulas with at most one free variable thereby obtaining so-called monodic fragments of FOTL. In this paper, we are concerned with constructing tableau algorithms for monodic fragments based on decidable fragments of first-order logic like the two-variable fragment or the guarded fragment. We present a general framework that shows how existing decision procedures for first-order (...) fragments can be used for constructing a tableau algorithm for the corresponding monodic fragment of FOTL. Some example instantiations of the framework are presented. (shrink)

Propositional dynamic logic (PDL) is one of the most successful variants of modal logic. To make it even more useful for applications, many extensions of PDL have been considered in the literature. A very natural and useful such extension is with negation of programs. Unfortunately, as long-known, reasoning with the resulting logic is undecidable. In this paper, we consider the extension of PDL with negation of atomic programs, only. We argue that this logic is still useful, e.g. in the context (...) of description logics, and prove that satisfiability is decidable and EXPTIME-complete using an approach based on Büchi tree automata. (shrink)

We study satisfiability and infinite-state model checking in ICPDL, which extends Propositional Dynamic Logic (PDL) with intersection and converse operators on programs. The two main results of this paper are that (i) satisfiability is in 2EXPTIME, thus 2EXPTIME-complete by an existing lower bound, and (ii) infinite-state model checking of basic process algebras and pushdown systems is also 2EXPTIME-complete. Both upper bounds are obtained by polynomial time computable reductions to ω-regular tree satisfiability in ICPDL, a reasoning problem that we introduce specifically (...) for this purpose. This problem is then reduced to the emptiness problem for alternating two-way automata on infinite trees. Our approach to (i) also provides a shorter and more elegant proof of Danecki's difficult result that satisfiability in IPDL is in 2EXPTIME. We prove the lower bound(s) for infinite-state model checking using an encoding of alternating Turing machines. (shrink)

The aim of this paper is to construct a tableau decision algorithm for the modal description logic K ALC with constant domains. More precisely, we present a tableau procedure that is capable of deciding, given an ALC-formula with extra modal operators (which are applied only to concepts and TBox axioms, but not to roles), whether is satisfiable in a model with constant domains and arbitrary accessibility relations. Tableau-based algorithms have been shown to be practical even for logics of rather high (...) complexity. This gives us grounds to believe that, although the satisfiability problem for K ALC is known to be NEXPTIME-complete, by providing a tableau decision algorithm we demonstrate that highly expressive description logics with modal operators have a chance to be implementable. The paper gives a solution to an open problem of Baader and Laux [5]. (shrink)

In this paper, we investigate the relationship between two decidable interval-based temporal description logics that have been proposed in the literature, T L-ALCF and ALCF. Although many aspects of these two logics are quite similar, the two logics suggest two rather different paradigms for representing temporal conceptual knowledge. In this paper, we exhibit a reduction from T L-ALCF concepts to ALCF concepts that serves two purposes: first, it nicely illustrates the relationship between the two knowledge representation paradigms; and second, it (...) provides a tight PSPACE upper bound for T L-ALCF concept satisfiabiliy, whose complexity was previously unknown. (shrink)

In recent years, the full text of papers are increasingly available electronically which opens up the possibility of quantitatively investigating citation contexts in more detail. In this study, we introduce a new form of citation analysis, which we call citation concept analysis (CCA). CCA is intended to reveal the cognitive impact certain concepts—published in a highly-cited landmark publication—have on the citing authors. It counts the number of times the concepts are mentioned (cited) in the citation context of citing publications. We (...) demonstrate the method using three classical highly cited books: (1) The structure of scientific revolutions by Thomas S. Kuhn, (2) The logic of scientific discovery—Logik der Forschung: Zur Erkenntnistheorie der modernen Naturwissenschaft in German—, and (3) Conjectures and refutations: the growth of scientific knowledge by Karl R. Popper. It is not surprising—as our results show—that Kuhn’s “paradigm” concept seems to have had a significant impact. What is surprising is that our results indicate a much larger impact of the concept “paradigm” than Kuhn’s other concepts, e.g., “scientific revolution”. The paradigm concept accounts for about 40% of the concept-related citations to Kuhn’s work, and its impact is resilient across all disciplines and over time. With respect to Popper, “falsification” is the most used concept derived from his books. Falsification is the cornerstone of Popper’s critical rationalism. (shrink)

Representative for contemporary attempts to establish a science of consciousness we examine Chalmers' statement and resolution of the 'hard problem of consciousness'. Agreeing with him that in order to account for subjectivity it is necessary to expand the ontology of the natural sciences, we argue that it is not sufficient to just add conscious experience to the list of fundamental features of the world. Instead, we turn to phenomenology as the philosophy of conscious experience and give an outline of Merleau-Ponty's (...) critique of the objectivist ontology underlying science which excludes subjectivity from the world. We reconstruct his proposal for a revised ontology in The Visible and the Invisible aiming at an extended understanding of Being including subjectivity, which takes on the form of a constellation of new ontological terms centered around the concept of the 'flesh of the world'. Trying to spell out the consequences of Merleau-Ponty's ontological considerations for scientific practice and especially the science of consciousness, we notice that his philosophy of subjectivity-in-the-world on its part is unable to connect to the insights of the natural sciences. The phenomenological critique of the 'hard problem' reveals a deeper disparity which, at present, limits its practical implications. (shrink)

Studies in experimental philosophy claim to document intuition variation. Some studies focus on demographic group-variation; Colaçoet al., for example, claim that age generates intuition variation regarding knowledge attribution in a fake-barn scenario. Other studies claim to show intuition variation when comparing the intuition of philosophers to that of non-philosophers. The main focus has been on documenting intuition variation rather than uncovering what underlying factor(s) may prompt such a phenomenon. We explore a number of suggested explanatory hypotheses put forth by Colaçoet (...) al., as well as an attempt to test Sosa's claim that intuition variance is a result of people ‘filling in the details’ of a thought experiment differently from one another. We show (i) that people respond consistently across conditions aimed at ‘filling in the details’ of thought experiments, (ii) that risk attitude does not seem relevant to knowledge ascription, (iii) that people's knowledge ascriptions do not vary due to views about defeasibility of knowledge. Yet, (iv) we find no grounds to reject that a large proportion of people appear to adhere to so-called subjectivism about knowledge, which may explain why they generally have intuitions about the fake-barn scenario that vary from those of philosophers. (shrink)

Studies in experimental philosophy claim to document intuition variation. Some studies focus on demographic group-variation; Colaço et al., for example, claim that age generates intuition variation regarding knowledge attribution in a fake-barn scenario. Other studies claim to show intuition variation when comparing the intuition of philosophers to that of non-philosophers. The main focus has been on documenting intuition variation rather than uncovering what underlying factor(s) may prompt such a phenomenon. We explore a number of suggested explanatory hypotheses put forth by (...) Colaço et al., as well as an attempt to test Sosa's claim that intuition variance is a result of people ‘filling in the details’ of a thought experiment differently from one another. We show (i) that people respond consistently across conditions aimed at ‘filling in the details’ of thought experiments, (ii) that risk attitude does not seem relevant to knowledge ascription, (iii) that people's knowledge ascriptions do not vary due to views about defeasibility of knowledge. Yet, (iv) we find no grounds to reject that a large proportion of people appear to adhere to so-called subjectivism about knowledge, which may explain why they generally have intuitions about the fake-barn scenario that vary from those of philosophers. (shrink)

Der emanzipatorische Ansatz des Denkens von Mably und Rousseau und ihre Zuneigung zum «Volk» können sich nicht konsequent zu einem geschlossenen politischen System entfalten, weil die vorindustrielle Sozialperspektive der Autoren und ihre ambivalente Haltung zu den noch traditionellen Unterschichten dem entgegenstehen. Folgerichtig gewinnen ihre politischen Theorien eine verwirrende Vielgestaltigkeit, die immer wieder zu einseitigen Interpretationen geführt hat.

Self-fulfillment of theories is argued to be a threat to social science in at least two ways. First, a realist might worry that self-fulfillment constitutes a threat to the idea that social science is a proper science consistent with a realist approach that develops true and successful statements about the world. Second, one might argue that the potential self-fulfilling nature of social science theories potentially undermines the ethical integrity of social scientists. We argue that if one accepts that social science (...) theories are not based on laws akin to those that govern natural reality or acknowledges that if one can predict self-fulfillment via a meta-theory that explains the underlying regularities of the self-fulfilling change, the threat to realism is dismantled. Furthermore, on the basis of these arguments, we show that if one is unable to predict the consequences of a theory, it is difficult to ascribe moral responsibility at the individual level. It is, therefore, not the potential self-fulfillment of theories per se that poses an ethical challenge, in contrast to claims in the literature. (shrink)

PLoS ONE 3(3): e1897. doi:10.1371/journal.pone.

"A commentary containing glosses on The Last Third of Book II, Book IV (De arte dialectica) entire, and approximately a third of Book V (De rhetorica) of Martianus Capella"--Introduction.

Seen from a national business system perspective, the notion of corporate social responsibility (CSR) emerges as a specifically US‐American response to challenges regarding the corporate place in society. With the spread of American capitalism, however, CSR is bound to come into contact – and conflict – with other approaches to the role of business in society that have been shaped by different national cultures. Within Europe, one such area of potential conflict concerns the role of organised labour in representing employee (...) interests. Studying the perceptions held by European trade unions on stakeholding, as one of the important concepts in the CSR discourse, does indeed reveal a considerable degree of union scepticism of CSR and its terminology. There is, however, also embryonic evidence of at least some unions attempting to link the CSR discourse to traditional union goals. Furthermore, national differences in union responses to CSR are beginning to emerge, which may, in turn, further shape the evolution of national business systems in Europe. (shrink)

Studies into corporate social responsibility (CSR) in small and medium-sized enterprises (SMEs) have suggested that small businesses are different to the large companies on which CSR research usually focusses. Extending this argument, this article raises the question what differences in approaches to CSR there are within the SME category. Analysing the CSR strategy and performance of a medium-sized fashion retailer in the United Kingdom through manager interviews as well as customer and employee surveys, the article develops an analytical framework of (...) CSR in small, medium and large firms. The argument is developed that medium-sized firms occupy a transition stage, where some CSR features that are reminiscent of small enterprises are still important but get overlaid with aspects that are more typical of large companies. (shrink)

Rich with analyses of concepts from deconstruction, systems theory, and post-Marxism, with critiques of fundamentalist thought and the war on terror, this ...

Aristotle earns the distinction of having put forward the first comprehensive philosophical theory of justice. After the end of the antique world, St. Thomas Aquinas was the first philosopher and theologian to return to Aristotles theory of justice. This will be followed by a summary of the core aspects of Aquinass treatise on law and political theory, and explicated accordingly.

This was the address given on the occasion of the award of the Goethe Institute’s Goethe Medal to the Hungarian philosopher Ágnes Heller in 2010. Other recipients of the Medal have included Bruno Bettelheim, György Ligeti, Ernst Gombrich, Karl Popper, and Lars Gustafsson.

The particular situation of the French administrative detention center medical units appears to be an exemplary case to study the difficulties facing medical practice. Indeed, the starting point of our inquiry was an amazing observation that needed to be addressed and understood: why are professional interpreters so seldom requested in ADC medical units, where one would expect that they would be “naturally” present? Aiming to fully explore the meanings of the “absent interpreter”, this article takes into account the possible meanings (...) of this situation: the recourse to professional interpreters in France is far from expected given cumulative evidence of its benefits; perceptions of illegal immigrants and medical habitus itself may both hamper the use of a third party; the ADCs are a very stressful place for healthcare professionals, with conflicting missions, political issues enmeshed with medical goals, and heavy affective burden that may lead to self-protection. Silencing voices of suffering others might be seen as the hidden indecent truth of the “absent interpreter”. These reflections open a window to a larger issue with regard to the full range of medicine: what are the place, the role and the function of patient’s words and narratives in contemporary medicine? The highly invested somatic perspective and its political corollary giving primacy to bare life harbor potential risks of obscuring speeches and undervaluing narratives. (shrink)

PurposeThe paper aims to explore future and emerging information and communication technologies. It gives a general overview of the social consequences and ethical issues arising from technologies that can currently be reasonably expected. This overview is used to present recommendations and integrate these in a framework of responsible innovation.Design/methodology/approachThe identification of emerging ICTs and their ethical consequences is based on the review and analysis if several different bodies of literature. The individual features of the ICTs and the ethical issues identified (...) this way are then aggregated and analysed.FindingsThe paper outlines the 11 ICTs identified. Some of the shared features that are likely to have social relevance include an increase in natural interaction, the invisibility of technology, direct links between humans and technology, detailed models and data of humans and an increasing autonomy of technology that may lead to power over the user. Ethical issues include several current topics such as privacy, data protection, intellectual property and digital divides. New problems may include changes to the way humans are perceived and the role of humans and technology in society. This includes changing power structures and different ways of treating humans.Research limitations/implicationsThe paper presents a piece of foresight research which cannot claim exact knowledge of the future. However, by developing a detailed understanding of possible futures it provides an important basis for current decisions relating to future technology development and governance.Practical implicationsThe paper spells out a range of recommendations for both policy makers and researchers/industry. These refer to the framework within which technology is developed and how such a framework could be designed to allow the development of ethical reflexivity.Social implicationsThe work described here is likely to influence EU policy on ICT research and technology research and innovation more broadly. This may have implications for the type of technologies funded and broad implications for the social use of emerging technologies.Originality/valueThe paper presents a novel and important broad view of the future of ICTs that is required in order to inform current policy decisions. (shrink)

In 1638, the Jesuit, poet, preacher, and historianJohannes Bisselius published the first volume of his seasonal poem Deliciae Veris, Pleasures of Spring. The subtly composed, stylistically unique cycle is presented here for the first time in a modern edition with a German translation and insightful commentary, including an introduction to each poem.".