Game-theoretic solution concepts describe sets of strategy profiles that are optimal for all players in some plausible sense. Such sets are often found by recursive algorithms like iterated removal of strictly dominated strategies in strategic games, or backward induction in extensive games. Standard logical analyses of solution sets use assumptions about players in fixed epistemic models for a given game, such as mutual knowledge of rationality. In this paper, we propose a different perspective, analyzing solution algorithms as processes of learning (...) which change game models. Thus, strategic equilibrium gets linked to fixed-points of operations of repeated announcement of suitable epistemic statements. This dynamic stance provides a new look at the current interface of games, logic, and computation. (shrink)

Current dynamic epistemic logics for analyzing effects of informational events often become cumbersome and opaque when common knowledge is added for groups of agents. Still, postconditions involving common knowledge are essential to successful multi-agent communication. We propose new systems that extend the epistemic base language with a new notion of ‘relativized common knowledge’, in such a way that the resulting full dynamic logic of information flow allows for a compositional analysis of all epistemic postconditions via perspicuous ‘reduction axioms’. We also (...) show how such systems can deal with factual alteration, rather than just information change, making them cover a much wider range of realistic events. After a warm-up stage of analyzing logics for public announcements, our main technical results are expressivity and completeness theorems for a much richer logic that we call LCC. This is a dynamic epistemic logic whose static base is propositional dynamic logic (PDL), interpreted epistemically. This system is capable of expressing all model-shifting operations with finite action models, while providing a compositional analysis for a wide range of informational events. This makes LCC a serious candidate for a standard in dynamic epistemic logic, as we illustrate by analyzing some complex communication scenarios, including sending successive emails with both ‘cc’ and ‘bcc’ lines, and other private announcements to subgroups. Our proofs involve standard modal techniques, combined with a new application of Kleene’s theorem on finite automata, as well as new Ehrenfeucht games of model comparison. (shrink)

It is common in the literature to claim that legitimacy is the right to rule and that, accordingly, Hohfeldian rights analysis can be used to understand the concept. However, we argue that authors in the legitimacy literature have not generally realised the full potential of Hohfeldian analysis. We discuss extant approaches in the literature that conceptually identify legitimacy with one particular Hohfeldian incident, or, more rarely, a determinate set of incidents. Against these views, and building on parallel debates in property (...) theory, we suggest that Hohfeldian analysis pushes one towards the claim that legitimacy possesses no determinate essence. We provide a rationale for this novel view and disarm a series of objections. (shrink)

Where should we meet? This may seem like a trivial decision, mostly focused on convenience. However, location can represent integral values, attitudes, and priorities. Especially when the meeting i...

Minimal predicates P satisfying a given first-order description φ(P) occur widely in mathematical logic and computer science. We give an explicit first-order syntax for special first-order ‘PIA conditions’ φ(P) which guarantees unique existence of such minimal predicates. Our main technical result is a preservation theorem showing PIA-conditions to be expressively complete for all those first-order formulas that are preserved under a natural model-theoretic operation of ‘predicate intersection’. Next, we show how iterated predicate minimization on PIA-conditions yields a language MIN(FO) equal (...) in expressive power to LFP(FO), first-order logic closed under smallest fixed-points for monotone operations. As a concrete illustration of these notions, we show how our sort of predicate minimization extends the usual frame correspondence theory of modal logic, leading to a proper hierarchy of modal axioms: first-order-definable, first-order fixed-point definable, and beyond. (shrink)

Rational agents base their actions on information from observation, inference, introspection, or other sources. But this information comes in different kinds, and it is usually handled by different logical mechanisms. We discuss how to integrate external ‘updating information’ and internal ‘elucidating information’ into one system of dynamic epistemic logic, by distinguishing two basic informational actions: ‘bare seeing’ versus ‘conscious realization’.

In the last few years, preference logic and in particular, the dynamic logic of preference change, has suddenly become a live topic in my Amsterdam and Stanford environments. At the request of the editors, this article explains how this interest came about, and what is happening. I mainly present a story around some recent dissertations and supporting papers, which are found in the references. There is no pretense at complete coverage of preference logic (for that, see Hanson 2001) or even (...) of preference change (Hanson 1995). (shrink)

Dov Gabbay is a prolific logician just by himself. But beyond that, he is quite good at making other people investigate the many further things he cares about. As a result, King's College London has become a powerful attractor in our field worldwide. Thus, it is a great pleasure to be an organizer for one of its flagship events: the Augustus de Morgan Workshop of 2005. Benedikt Loewe and I proposed the topic of 'interactive logic' for this occasion, with an (...) emphasis on social software – the logical analysis and design of social procedures – and on games, arguably the formal interactive setting par excellence. This choice reflects current research interests in our logic community at ILLC Amsterdam and beyond. In this broad area of interfaces between logic, computer science, and game theory, this paper is my own attempt at playing Dov. I am, perhaps not telling, but at least asking other people to find out for me what I myself cannot. (shrink)

How can we assess the epistemic quality of democratic decision-making? Sceptics doubt such assessments are possible, as they must rely on controversial substantive standards of truth and rightness. Challenging that scepticism, this paper suggests a procedure-independent standard for assessing the epistemic quality of democratic decision-making by evaluating whether it is adequately supported by reasons. Adequate support for conclusion is a necessary aspect of epistemic quality for any epistemic justification of democracy, though particularly relevant to theories that emphasize public deliberation. Finding (...) existing methods for measuring the quality of public discourse to fall short, we draw on an epistemological theory of argumentation to provide a more sophisticated approach to evaluating the epistemic quality of democratic decision-making, illustrate how the approach can be used, and demonstrate its relevance for the epistemic turn in democratic theory. (shrink)

Transition systems can be viewed either as process diagrams or as Kripke structures. The rst perspective is that of process theory, the second that of modal logic. This paper shows how various formalisms of modal logic can be brought to bear on processes. Notions of bisimulation can not only be motivated by operations on transition systems, but they can also be suggested by investigations of modal formalisms. To show that the equational view of processes from process algebra is closely related (...) to modal logic, we consider various ways of looking at the relation between the calculus of basic process algebra and propositional dynamic logic. More concretely, the paper contains preservation results for various bisimulation notions, a result on the expressive power of propositional dynamic logic, and a de nition of bisimulation which is the proper notion of invariance for concurrent propositional dynamic logic. (shrink)

Though doubtless two of the leading philosophers in ethics today, Habermas and Levinas have yet to be subjected to sys tematic comparison. This essay undertakes a first step. Differences of terminology aside, Habermas and Levinas can be seen to pursue, via separate routes, a similar core idea. I term this the idea of immanent normativity. While Habermas locates an unchosen normative pull in the medium of interpersonal communication, Levinas locates an unconditional ethical command in the Other as face. Hence they (...) unite in strongly opposing social contract theory's notion of moral ity as optional and of responsibility as conditional upon self-interest. Key Words: contractualism • Habermas • Levinas • vulnerability. (shrink)

This article shows how eco-theology could and should be indigenised in an African context using the Copperbelt in Zambia as a case study. The ecological crisis worldwide has given rise to the call for everyone to work together to start caring about our natural environment. In theology, the response to this call received the name eco-theology. By means of a literature review, ethnographic information and governmental legislation, the article tries to illustrate how eco-theology could and should be indigenised in an (...) African context using the Copperbelt in Zambia as a case study. This article makes an attempt to contribute to the needed ecological renewal by reinterpreting two traditions that inform thinking on the Copperbelt: Christianity and African traditional religion. The supernatural belief of the Lamba people is no longer embodied in this creation, and it is not too late for the people to form any indigenous environmental protection movement to protect the sacredness of mother Earth from further contamination and exploitation by strengthening, maintaining and respecting the traditional teachings and the cultural laws. Obedience to God’s command to tend creation is a quest for continued creation by humans, so that value is added to what is already in existence. This is embodied making the place we live in more beautiful, appealing and peaceful. Fruitfulness with sustainability becomes core values for interdependence and earth keeping.Contribution: We wish to address the ecological situation of the mining industry in Zambia from a theological perspective by assessing the impact of the copper mining and processing industry on humans, their environment and nature and by showing how the traditions of African traditional religion thought can be transformed into tools to oppose this ecological disaster. (shrink)

Sportfilosofie en haar centrale vragen Sportfilosofie heeft haar academische wortels in de jaren zeventig van de vorige eeuw, met de oprichting van de International Association for the Philosophy of Sport en het Journal of the Philosophy of Sport . In Nederland heeft sportfilosofie een academische plek verworven aan het begin van de jaren negentig aan de Faculteit der Bewegingswetenschappen.

Natural languages are vehicles of information, arguably the most important, certainly the most ubiquitous that humans possess. Our everyday interactions with the world, with each other and with ourselves depend on them. And even where in the specialised contexts of science we use dedicated formalisms to convey information, their use is embedded in natural language. This omnipresence of natural language is due in large part to its flexibility, which is almost always a virtue, sometimes a vice. Natural languages are able (...) to carry information in a wide variety of ways, about a seemingly unlimited range of topics, which makes them both efficient and versatile, and hence useful in almost every circumstance. But sometimes, when pinpoint precision is what counts, this versatility can get in the.. (shrink)

Keuze van artikelen uit het werk van de Vlaamse filosoof over wetenschap, milieu, en medische en biologische ethiek.

Is Nederland een fraudeland geworden? Na alle berichten over boekhoudschandalen en het bekend worden van illegale prijsafspraken is het terecht dat die vraag wordt gesteld. Het oplichten van aandeelhouders of van klanten gaat in tegen verschillende ethische noties. Het verstrekken van onjuiste informatie is niet alleen vanuit een utilistisch standpunt verwerpelijk vanwege de economische schade die ontstaat doordat een optimale marktwerking belemmerd wordt. Ook vanuit een deontologisch perspectief staan de ethische seinen op rood: het bedriegen van aandeelhouders of klanten getuigt (...) van weinig respect en is onrechtvaardig omdat dit zelfverrijking mogelijk maakt ten koste gaat van de stakeholders. Ook vanuit het perspectief van de deugdenethiek zijn deze praktijken verwerpelijk: het achterhouden van informatie getuigt van een gebrek aan integriteit en heeft een negatieve voorbeeldfunctie naar anderen. (shrink)

This paper develops propositions on the added value for SMEs of normatively based, employee-oriented corporate social responsibility (CSR). We suggest that not only motives but also the skills of the owner/manager as an institutional entrepreneur are critical in dealing with institutional variance. Also, the transfer of employee-oriented CSR can have positive results for SMEs that could imply that globalisation is not only a race to the bottom.

Hot spot policing is an established concept that is proven to reduce crime. It is mostly done through foot patrol or car patrols. In the present study it is tested whether helicopters can produce a deterrent policing effect to reduce the amount of vehicle arsons in Sweden on larger hot areas. Sweden tends to have elevated levels of vehicle arsons in August, with about 20% of police districts responsible for 50% of the cases. The risk narrative revolves around youth congregating (...) in public places in deprived neighborhoods to generate disturbances, and the disruption of the risk narrative tested here is based on providing deterrence through helicopter police presence. During 6 weeks in August and September of 2019 police helicopters patrolled four police districts in Sweden to attempt to prevent vehicle arsons. Our data comprise police reports of vehicle arson, and time stamped satellite data over the location for police helicopters. The evaluation considers whether there is an intention to treat effect from this project, in addition to whether there is an effect of actual helicopter presence. The study finds no significant effect of intention to treat, nor of actual dosage. (shrink)

Eighteenth-century German Statistik was an empirical and descriptive discipline of "the land and the people." As the study of material conditions it provided governments with information to assess the strength of their own state in comparison with others. Its adherents' claim that Statistik was a useful science, however, was severely tempered by their empirical method and holistic view of society. As a "science of the present" it was seriously challenged by the recognition of the essential historicity of its subject matter. (...) Both circumstances explain the decline of Statistik from which mathematical statistics, political economy, and political historiography profited. (shrink)

The meaning of have is notoriously difficult to define; sometimes it seems to denote possession, but often, it seems to denote nothing, only to complicate composition. This paper focuses on the cases where have embeds a small clause, proposing that all it accomplishes is abstraction, turning the small clause into a predicate. This analysis is extended to the cases where have appears to embed DPs: These objects are interpreted as small clauses as well, with implicit predicates denoting possession or—with relational (...) nouns—nothing. (shrink)

The following book Social Justice: A Sketch of the West and Islamic World Experiences contains a collection of articles that may be read individually, each concerned with the same issues of social justice. The writers in this book originate from the Western and Islamic World’s countries. All have agreed to explore and contribute to understanding social justice in each pertinent countries’ experiences. The problems being addressed are either descriptive or valuational and, in most cases, are the combination of both. All (...) articles presented in this collection are mainly a reexamination of social justice ideals from the authors’ viewpoints and experiences and how the ideals may be applicable and considered relevant to a particular problem faced by the respective countries. As its generic meaning is commonly recognized, all authors see that social justice is the most fundamental virtue, crucially providential, to be the basis of interpersonal relations ordering and establishing and maintaining a stable political society. While the nature, origin, and legitimate application of social justice are a thing that may be debatable, all authors in this book concur with the notion that there is a need to struggle for a just society. This idea may be best developed to respect persons as free, rational agents without ignoring the particularities of its communities’ challenges, characters, and identities. (shrink)