Reasoning About Knowledge is the first book to provide a general discussion of approaches to reasoning about knowledge and its applications to distributed ...

Although it is known that reachability in undirected finite graphs can be expressed by an existential monadic second-order sentence, our main result is that this is not the case for directed finite graphs (even in the presence of certain "built-in" relations, such as the successor relation). The proof makes use of Ehrenfeucht-Fraisse games, along with probabilistic arguments. However, we show that for directed finite graphs with degree at most k, reachability is expressible by an existential monadic second-order sentence.

What is an inference rule? This question does not have a unique answer. One usually finds two distinct standard answers in the literature; validity inference $(\sigma \vdash_\mathrm{v} \varphi$ if for every substitution $\tau$, the validity of $\tau \lbrack\sigma\rbrack$ entails the validity of $\tau\lbrack\varphi\rbrack)$, and truth inference $(\sigma \vdash_\mathrm{t} \varphi$ if for every substitution $\tau$, the truth of $\tau\lbrack\sigma\rbrack$ entails the truth of $\tau\lbrack\varphi\rbrack)$. In this paper we introduce a general semantic framework that allows us to investigate the notion of inference (...) more carefully. Validity inference and truth inference are in some sense the extremal points in our framework. We investigate the relationship between various types of inference in our general framework, and consider the complexity of deciding if an inference rule is sound, in the context of a number of logics of interest: classical propositional logic, a nonstandard propositional logic, various propositional modal logics, and first-order logic. (shrink)

We do a quantitative analysis of modal logic. For example, for each Kripke structure M, we study the least ordinal μ such that for each state of M, the beliefs of up to level μ characterize the agents' beliefs (that is, there is only one way to extend these beliefs to higher levels). As another example, we show the equivalence of three conditions, that on the face of it look quite different, for what it means to say that the agents' (...) beliefs have a countable description, or putting it another way, have a "countable amount of information". The first condition says that the beliefs of the agents are those at a state of a countable Kripke structure. The second condition says that the beliefs of the agents can be described in an infinitary language, where conjunctions of arbitrary countable sets of formulas are allowed. The third condition says that countably many levels of belief are sufficient to capture all of the uncertainty of the agents (along with a technical condition). The fact that all of these conditions are equivalent shows the robustness of the concept of the agents' beliefs having a "countable description". (shrink)

The descriptive complexity of a problem is the complexity of describing the problem in some logical formalism. One of the few techniques for proving separation results in descriptive complexity is to make use of games on graphs played between two players, called the spoiler and the duplicator. There are two types of these games, which differ in the order in which the spoiler and duplicator make various moves. In one of these games, the rules seem to be tilted towards favoring (...) the duplicator. These seemingly more favorable rules make it easier to prove separation results, since separation results are proven by showing that the duplicator has a winning strategy. In this paper, the relationship between these games is investigated. It is shown that in one sense, the two games are equivalent. Specifically, each family of graphs used in one game to prove a separation result can in principle be used in the other game to prove the same result. This answers an open question of Ajtai and the author from 1989. It is also shown that in another sense, the games are not equivalent, in that there are situations where the spoiler requires strictly more resources to win one game than the other game. This makes formal the informal statement that one game is easier for the duplicator to win. (shrink)

We consider the issue of what an agent or a processor needs to know in order to know that its messages are true. This may be viewed as a first step to a general theory of cooperative communication in distributed systems. An honest message is one that is known to be true when it is sent (or said). If every message that is sent is honest, then of course every message that is sent is true. Various weaker considerations than honesty (...) are investigated with the property that provided every message sent satisfies the condition, then every message sent is true. (shrink)

ABSTRACT:The notion of stakeholder salience based on attributes (e.g., power, legitimacy, urgency) is applied in the family business setting. We argue that where principal institutions intersect (i.e., family and business); managerial perceptions of stakeholder salience will be different and more complex than where institutions are based on a single dominant logic. We propose that (1) whereas utilitarian power is more likely in the general business case, normative power is more typical in family business stakeholder salience; (2) whereas in a general (...) business context legitimacy is socially constructed; for family stakeholders, legitimacy is based on heredity; and (3) whereas temporality and criticality are somewhat independent in general-business urgency, they are linked in the family business case because of family ties and family-centered non-economic goals. We apply this theoretical framework to position and integrate the contributions to this special section ofBusiness Ethics Quarterlyon “Stakeholder Theory, Ethics, Corporate Social Responsibility, and Family Enterprise.”. (shrink)

ABSTRACT:The notion of stakeholder salience based on attributes (e.g., power, legitimacy, urgency) is applied in the family business setting. We argue that where principal institutions intersect (i.e., family and business); managerial perceptions of stakeholder salience will be different and more complex than where institutions are based on a single dominant logic. We propose that (1) whereas utilitarian power is more likely in the general business case, normative power is more typical in family business stakeholder salience; (2) whereas in a general (...) business context legitimacy is socially constructed; for family stakeholders, legitimacy is based on heredity; and (3) whereas temporality and criticality are somewhat independent in general-business urgency, they are linked in the family business case because of family ties and family-centered non-economic goals. We apply this theoretical framework to position and integrate the contributions to this special section ofBusiness Ethics Quarterlyon “Stakeholder Theory, Ethics, Corporate Social Responsibility, and Family Enterprise.”. (shrink)

Virtue ethics is now widely recognized as an alternative to Kantian and consequentialist ethical theories. However, moral philosophers have been slow to bring virtue ethics to bear on topics in applied ethics. Moreover, environmental virtue ethics is an underdeveloped area of environmental ethics. Although environmental ethicists often employ virtue-oriented evaluation (such as respect, care, and love for nature) and appeal to role models (such as Henry Thoreau, Aldo Leopold, and Rachel Carson) for guidance, environmental ethics has not been well informed (...) by contemporary work on virtue ethics. With _Character and Environment_, Ronald Sandler remedies each of these deficiencies by bringing together contemporary work on virtue ethics with contemporary work on environmental ethics. He demonstrates the many ways that any ethic of character can and should be informed by environmental considerations. He also develops a pluralistic virtue-oriented environmental ethic that accommodates the richness and complexity of our relationship with the natural environment and provides effective and nuanced guidance on environmental issues. These projects have implications not only for environmental ethics and virtue ethics but also for moral philosophy more broadly. Ethical theories must be assessed on their theoretical and practical adequacy with respect to all aspects of the human ethical situation: personal, interpersonal, and environmental. To the extent that virtue-oriented ethical theory in general, and Sandler's version of it in particular, provides a superior environmental ethic to other ethical theories, it is to be preferred not just as an environmental ethic but also as an ethical theory. _Character and Environment_ will engage any reader with an interest in environmental ethics, virtue ethics, or moral philosophy. (shrink)

In many traditional, small-scale societies, death and other misfortunes are commonly explained as a result of others’ malign occult agency. Here, we call this family of epistemic tendencies “the agential view of misfortune.” After reviewing several ethnographic case studies that illustrate this view, we argue that its origins and stability are puzzling from an evolutionary perspective. Not only is the agential view of misfortune false; it imposes costs on individuals and social groups that seem to far outweigh whatever benefits the (...) view might provide. We thus doubt that the agential view of misfortune is explainable in terms of adaptive effects. However, neither does it seem readily explainable as a consequence of belief formation strategies that are on the whole adaptive (as is plausibly the case for certain other of our false beliefs, including some that are costly). Accordingly, we contend that the commonness of the agential view of misfortune demands a special evolutionary explanation of some kind. We provide a partial explanation of this phenomenon by highlighting the adaptive benefits that often flow to occult specialists in environments where the agential view of misfortune is entrenched. What this does not explain, however, is the general lack of resistance we observe in response to occultists’ exploitative behaviours over (cultural) evolutionary timescales. We conclude by canvassing a few possible explanations for this puzzling lack of resistance, and while we commit ourselves to none, we do find one option more promising than the others. (shrink)

Virtue ethics is now widely recognized as an alternative to Kantian and consequentialist ethical theories. However, moral philosophers have been slow to bring virtue ethics to bear on topics in applied ethics. Moreover, environmental virtue ethics is an underdeveloped area of environmental ethics. Although environmental ethicists often employ virtue-oriented evaluation and appeal to role models for guidance, environmental ethics has not been well informed by contemporary work on virtue ethics. With _Character and Environment_, Ronald Sandler remedies each of these (...) deficiencies by bringing together contemporary work on virtue ethics with contemporary work on environmental ethics. He demonstrates the many ways that any ethic of character can and should be informed by environmental considerations. He also develops a pluralistic virtue-oriented environmental ethic that accommodates the richness and complexity of our relationship with the natural environment and provides effective and nuanced guidance on environmental issues. These projects have implications not only for environmental ethics and virtue ethics but also for moral philosophy more broadly. Ethical theories must be assessed on their theoretical and practical adequacy with respect to all aspects of the human ethical situation: personal, interpersonal, and environmental. To the extent that virtue-oriented ethical theory in general, and Sandler's version of it in particular, provides a superior environmental ethic to other ethical theories, it is to be preferred not just as an environmental ethic but also as an ethical theory. _Character and Environment_ will engage any reader with an interest in environmental ethics, virtue ethics, or moral philosophy. (shrink)

Persons in Community sounds a clear call for African voices to be heard in the global village. It explores the interface between traditional African ethics and contemporary issues, both locally and globally. The contributors to this book offer incisive perspectives on cultural values - such as ubuntu - in a wide range of areas: the workplace and Western capitalism, medical practices, government and political change, gender relationships and HIV/AIDS. What emerges is that there are distinctive and common strands in ethical (...) views from sub-Saharan Africa, which need to be examined, sometimes applauded, and sometimes challenged. (shrink)

It is uncontroversial that character ethics are indispensible to environmental ethics. What is contested is whether virtue ethics, understood as a distinctive type of normative theory, could provide a viable environmental ethic. In response to this concern, this chapter explicates what is distinctive about a virtue ethics approach to normativity within environmental ethics—that is, that how things matter is explicated through the virtues; demonstrates that a virtue ethics normative framework can accommodate whatever is the correct account of the value of (...) nonhuman nature; argues that a pluralistic approach to moral status, such as virtue ethics’, is indispensible to environmental ethics; articulates a plausible virtue ethics principle of right action and decision making. Virtue ethics should be regarded as a viable approach to environmental ethics, and it should be considered alongside other, more familiar, approaches such as deontology and consequentialism. (shrink)

Experiments are presented showing that visual search for Mueller-Lyer (ML) stimuli is based on complete configurations, rather than component segments. Segments easily detected in isolation were difficult to detect when embedded in a configuration, indicating preemption by low-level groups. This preemption—which caused stimulus components to become inaccessible to rapid search—was an all-or-nothing effect, and so could serve as a powerful test of grouping. It is shown that these effects are unlikely to be due to blurring by simple spatial filters at (...) early visual levels. It is proposed instead that they are due to more sophisticated processes that rapidly bind contour fragments into spatially-extended assemblies. These results support the view that rapid visual search cannot access the primitives formed at the earliest stages of visual processing; rather, it can access only higher-level, more ecologically-relevant structures. (shrink)

This text is not only perfect for a college course in argument analysis, but also as a reference tool when confronted with arguments outside the classroom experience.

Bad Faith and Sincerity: Does Sartre's Analysis Rest on a Mistake? In this opening chapter, I intend to deal with an issue that vexed my earliest ...

Provides a broad overview of the structures, events and ideas in the world. Includes sections on physical and biological existence, God and religion, and the human condition"--Provided by publisher.

This essay is part of a dossier on Cristina Lafont's book Democracy without Shortcuts.

In this chapter I consider the place of the topic of racial and ethnic urban residential segregation factors into political philosophy. I begin with a short history of residential segregation and the ghetto, and their role in systems of racial domination and oppression, and remarks on the general neglect of this topic in contemporary political philosophy, including in nonideal political philosophy, which proports to take on examples of real-world injustices and inequalities. I then examine, from the standpoint of liberal-egalitarian political (...) theory, what segregation, as a concept, entails, and its harms to individuals, communities, and societies. Segregation in all its forms (residential, educational, and employment, as well as in political and legal systems) is an instance of injustice and inequality and a major component of processes that maintain injustice and inequality, so it requires correction and rectification of some sort. Desegregation and integration are typically forwarded as solutions to the ills and injustices of segregation. They seem synonymous, but are they? To answer this question, I survey the prominent conceptualizations of both during the civil rights movement and the contemporary debate over those terms and political theoretical positions. In the conclusion I outline my partial defense of the idea of integration. (shrink)

First, I briefly characterize Dretske’s particular naturalization project, emphasizing his naturalistic reconstruction of the notion of representation. Second, I note some apparent similarities between his notion of representation and Husserl’s notion of intentionality, but I find even more important differences. Whereas Husserl takes intentionality to be an intrinsic, phenomenological feature of thought and experience, Dretske advocates an “externalist” account of mental representation. Third, I consider Dretske’s treatment of qualia, because he takes it to show that his representational account of mind (...) succeeds in naturalizing even the “subjective” features of experience. I claim that Dretske's argument for his account of qualia turns on an ambiguous characterization of qualia. I conclude that he succeeds in naturalizing qualia only if qualia are understood as nonphenomenological features of experience and that he therefore has less to say than he thinks about the subjective life of beings such as us. (shrink)

The past few years have seen a resurgence of interest in the scientific study of magic. Despite being only a few years old, this “new wave” has already resulted in a host of interesting studies, often using methods that are both powerful and original. These developments have largely borne out our earlier hopes (Kuhn et al., 2008) that new opportunities were available for scientific studies based on the use of magic. And it would seem that much more can still be (...) done along these lines. -/- But in addition to this, we also suggested that it might be time to consider developing an outright science of magic—a distinct area of study concerned with the experience of wonder that results from encountering an apparently impossible event1. To this end, we proposed a framework as to how this might be achieved (Rensink and Kuhn, 2015). A science can be viewed as a systematic method of investigation involving three sets of issues: (i) the entities considered relevant, (ii) the kinds of questions that can be asked about them, and (iii) the kinds of answers that are legitimate (Kuhn, 1970). In the case of magic, we suggested that this could be done at three different levels, each focusing on a distinct set of issues concerned with the nature of magic itself: (i) the nature of magical experience, (ii) how individual magic tricks create this experience, and (iii) organizing knowledge of the set of known tricks in a more comprehensive way (Rensink and Kuhn, 2015). Our framework also included a base level focused on how the methods of magic could be used as tools to investigate issues in existing fields of study. -/- Lamont (2010) and Lamont et al. (2010) raised a number of concerns about the possibility of such a science, which we have addressed (Rensink and Kuhn, 2015). More recently, Lamont (2015) raised a new objection, arguing that although base-level work (i.e., applications of magic methods) might be useful, there is too little structure in magic tricks for them to be studied in a systematic way at the other levels, ruling out a science of magic. We argue here, however, that although this concern raises some interesting challenges for this science, it does not negate the possibility that it could exist, and could contribute to the study of the mind. (shrink)

D. C. Matthew argues that although integration offers blacks social and economic benefits, it also creates the conditions for phenotypic devaluation that leads to harm against black self-worth and servile behavior. Therefore, he advises against integration because the resulting self-worth harms outweigh the benefits of integration. I argue that Matthew’s cost-benefit calculation against integration lacks the requisite evidence, and amounts to a luxury belief that will result in more harm. Moreover, his interpretation of behavior — which he construes as being (...) indicative of a lack of self-worth — is unfounded. Further, his cost-benefit calculation results in socially reactionary sexual policing and ideological purity tests. (shrink)

The capacity of visual attention/STM can be determined by change-detection experiments. Detecting the presence of change leads to an estimate of 4 items, while detecting the absence of change leads to an estimate of 1 item. Thus, there are two magical numbers in vision: 4 and 1. The underlying limits, however, are not necessarily those of central STM.