We need to understand the impossible. Francesco Berto and Mark Jago start by considering what the concepts of meaning, information, knowledge, belief, fiction, conditionality, and counterfactual supposition have in common. They are all concepts which divide the world up more finely than logic does. Logically equivalent sentences may carry different meanings and information and may differ in how they're believed. Fictions can be inconsistent yet meaningful. We can suppose impossible things without collapsing into total incoherence. Yet for the leading philosophical (...) theories of meaning, these phenomena are an unfathomable mystery. To understand these concepts, we need a metaphysical, logical, and conceptual grasp of situations that could not possibly exist: Impossible Worlds. This book discusses the metaphysics of impossible worlds and applies the concept to a range of central topics and open issues in logic, semantics, and philosophy. It considers problems in the logic of knowledge, the meaning of alternative logics, models of imagination and mental simulation, the theory of information, truth in fiction, the meaning of conditional statements, and reasoning about the impossible. In all these cases, impossible worlds have an essential role to play. (shrink)

The Description Logic Handbook covers all aspects of the research in the field of knowledge representation. Written by some of the most prominent researchers in the field, and covering the basic technical material and implementational aspects, it is both a unique reference and a self-study guide.

John Broome has developed an account of rationality and reasoning which gives philosophical foundations for choice theory and the psychology of rational agents. We formalize his account into a model that differs from ordinary choice-theoretic models through focusing on psychology and the reasoning process. Within that model, we ask Broome’s central question of whether reasoning can make us more rational: whether it allows us to acquire transitive preferences, consistent beliefs, non-akratic intentions, and so on. We identify three structural types of (...) rationality requirements: consistency requirements, completeness requirements, and closedness requirements. Many standard rationality requirements fall under this typology. Based on three theorems, we argue that reasoning is successful in achieving closedness requirements, but not in achieving consistency or completeness requirements. We assess how far our negative results reveal gaps in Broome's theory, or deficiencies in choice theory and behavioral economics. (shrink)

Condorcet's famous jury theorem reaches an optimistic conclusion on the correctness of majority decisions, based on two controversial premises about voters: they are competent and vote independently, in a technical sense. I carefully analyse these premises and show that: whether a premise is justi…ed depends on the notion of probability considered; none of the notions renders both premises simultaneously justi…ed. Under the perhaps most interesting notions, the independence assumption should be weakened.

In Public Reason Confucianism, Sungmoon Kim presents an important Confucian political theory that seeks to combine a specific conception of Confucianism and the ideal of public reason. My article examines this theory and identifies some of the theoretical complications with Rawlsian public reason.

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

All existing impossibility theorems on judgment aggregation require individ- ual and collective judgment sets to be consistent and complete (in some recent results with completeness relaxed to deductive closure), arguably a demand- ing rationality requirement. They do not carry over to aggregation functions mapping pro…les of (merely) consistent individual judgment sets to (merely) consistent collective ones. We prove that, whenever the agenda of propositions under consideration exhibits mild interconnections, any such aggregation func- tion that is "neutral" between the acceptance and (...) rejection of each proposition is dictatorial. We relate this theorem to the literature. (shrink)

How can the propositional attitudes of several individuals be aggregated into overall collective propositional attitudes? Although there are large bodies of work on the aggregation of various special kinds of propositional attitudes, such as preferences, judgments, probabilities and utilities, the aggregation of propositional attitudes is seldom studied in full generality. In this paper, we seek to contribute to filling this gap in the literature. We sketch the ingredients of a general theory of propositional attitude aggregation and prove two new theorems. (...) Our first theorem simultaneously characterizes some prominent aggregation rules in the cases of probability, judgment and preference aggregation, including linear opinion pooling and Arrovian dictatorships. Our second theorem abstracts even further from the specific kinds of attitudes in question and describes the properties of a large class of aggrega tion rules applicable to a variety of belief-like attitudes. Our approach integrates some previously disconnected areas of investigation. (shrink)

Condorcet's famous jury theorem reaches an optimistic conclusion on the correctness of majority decisions, based on two controversial premises about voters: they are competent and vote independently, in a technical sense. I carefully analyse these premises and show that: (i) whether a premise is justi…ed depends on the notion of probability considered; (ii) none of the notions renders both premises simultaneously justi…ed. Under the perhaps most interesting notions, the independence assumption should be weakened.

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)

Emotions are a core factor of learning. Studies have shown that multiple emotions are co-experienced during learning and have a significant impact on learning outcomes. The present study investigated the importance of multiple, co-occurring emotions during learning about human biology with MetaTutor, a hypermedia-based intelligent tutoring system. Person-centered as well as variable-centered approaches of cluster analyses were used to identify emotion clusters. The person-centered clustering analyses indicated three emotion profiles: a positive, negative and neutral profile. Students with a negative profile (...) learned less than those with other profiles and also reported less usage of emotion regulation strategies. Emotion clusters identified through spectral co-clustering confirmed these results. Throughout the learning activity, emotions built a stable correlational structure of a positive, a negative, a neutral and a boredom emotion cluster. Positive emotion cluster scores before the learning activity and negative emotion cluster scores during the learning activity predicted learning, but not consistently. These results reveal the importance of negative emotions during learning with MetaTutor. Potential moderating factors and implications for the design and development of educational interventions that target emotions and emotion regulation with digital learning environments are discussed. (shrink)

Although critical differences exist between large companies and small‐ and medium‐sized enterprises (SMEs), limited empirical research has been done on human resource (HR)‐related corporate social responsibility (CSR). In this paper we study aging workforce management (AWM) as a component of CSR. Our study was conducted in the Netherlands through a randomly distributed online questionnaire. Managers and team leaders of 201 SMEs responded. The data were analyzed using multiple hierarchical regression analysis. Our results are twofold: first, findings suggest that CSR policies (...) in micro organizations with fewer than five employees seem to be strongly associated with AWM; and second, that companies with a focus on integration of older workers in daily activities do not perceive their actions as HR‐related. Using AWM as part of CSR helps to give insight into the role of the owner, company size and the nature of implicit CSR practices. Our study demonstrates that the use of AWM in CSR research can lead to valuable insights and therefore, our overarching research question is answered that AWM can be used when studying CSR. (shrink)

Feature logics are the logical basis for so-called unification grammars studied in computational linguistics. We investigate the expressivity of feature terms with negation and the functional uncertainty construct needed for the description of long-distance dependencies and obtain the following results: satisfiability of feature terms is undecidable, sort equations can be internalized, consistency of sort equations is decidable if there is at least one atom, and consistency of sort equations is undecidable if there is no atom.

Philosophers who take rationality to consist in the satisfaction of rational requirements typically favour rational requirements that govern mental attitudes at a time rather than across times. One such account has been developed by Broome in Rationality through reasoning. He claims that diachronic functional properties of intentions such as settling on courses of actions and resolving conflicts are emergent properties that can be explained with reference to synchronic rational pressures. This is why he defends only a minimal diachronic requirement which (...) characterises forgetting as irrational. In this paper, I show that Broome’s diachronically minimalist account lacks the resources to explain how a rational agent may resolve incommensurable choices by an act of will. I argue that one can solve this problem by either specifying a mode of diachronic deliberation or by introducing a genuinely diachronic requirement that governs the rational stability of an intention via a diachronic counterfactual condition concerning rational reconsideration. My proposal is similar in spirit to Gauthier’s account in his seminal paper ‘Assure and threaten’. It improves on his work by being both more general and explanatorily richer in its application with regard to diachronic phenomena such as transformative choices and acts of will. (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 solving judgment aggregation problems, groups often face constraints. Many decision problems can be modelled in terms the acceptance or rejection of certain propositions in a language, and constraints as propositions that the decisions should be consistent with. For example, court judgments in breach-of-contract cases should be consistent with the constraint that action and obligation are necessary and sufficient for liability; judgments on how to rank several options in an order of preference with the constraint of transitivity; and judgments on (...) budget items with budgetary constraints. Often more or less demanding constraints on decisions are imaginable. For instance, in preference ranking problems, the transitivity constraint is often contrasted with the weaker acyclicity constraint. In this paper, we make constraints explicit in judgment aggregation by relativizing the rationality conditions of consistency and deductive closure to a constraint set, whose variation yields more or less strong notions of rationality. We review several general results on judgment aggregation in light of such constraints. (shrink)

: "Work on aspect has long focussed on classifications of linguistic expressions into aspectual types, or Vendler-classes. Typical Vendler-classes include states, processes, and events. Such classifications miss the important generalization about aspectual interpretationthat it is a compositional process. It has been noted in the literature that terms can switch Vendler-classes; this has been called the category-switch problem. In our analysis, it is proposed that meanings and not expressions fall into aspectual classes, and that the aspectual type of a meaning is (...) derived by a process of aspectual composition. This process operates on underlying generalized activities that are similar to the nuclei proposed by Moens & Steedman, which in turn resemble plans.The interplay between semantic selection for a certain aspectual type and the application of type-changing operators to the meanings of verbphrases and sentences that occurs during aspectual composition constitutes weak aspectual type coercion. Our approach is illustrated with a unification-based grammar fragment that accounts for aspectual composition with certain adverbials, such as in a day or for an hour.". (shrink)

How can the propositional attitudes of several individuals be aggregated into overall collective propositional attitudes? Although there are large bodies of work on the aggregation of various special kinds of propositional attitudes, such as preferences, judgments, probabilities and utilities, the aggregation of propositional attitudes is seldom studied in full generality. In this paper, we seek to contribute to …lling this gap in the literature. We sketch the ingredients of a general theory of propositional attitude aggregation and prove two new theorems. (...) Our …rst theorem simultaneously characterizes some prominent aggregation rules in the cases of probability, judgment and preference aggregation, including linear opinion pooling and Arrovian dictatorships. Our second theorem abstracts even further from the speci…c kinds of attitudes in question and describes the properties of a large class of aggregation rules applicable to a variety of belief-like attitudes. Our approach integrates some previously disconnected areas of investigation. (shrink)

Group decisions must often obey exogenous constraints. While in a preference aggregation problem constraints are modelled by restricting the set of feasible alternatives, this paper discusses the modelling of constraints when aggregating individual yes/no judgments on interconnected propositions. For example, court judgments in breach-of-contract cases should respect the constraint that action and obligation are necessary and sufficient for liability, and judgments on budget items should respect budgetary constraints. In this paper, we make constraints in judgment aggregation explicit by relativizing the (...) rationality conditions of consistency and deductive closure to a constraint set, whose variation yields more or less strong notions of rationality. This approach of modelling constraints explicitly contrasts with that of building constraints as axioms into the logic, which turns compliance with constraints into a matter of logical consistency and thereby conflates requirements of ordinary logical consistency (such as not to affirm both a proposition and its negation) and requirements dictated by the environment (such as budgetary constraints). We present some general impossibility results on constrained judgment aggregation; they are immediate corollaries of known results on (unconstrained) judgment aggregation. (shrink)