Epistemic logic has grown from its philosophical beginnings to find diverse applications in computer science, and as a means of reasoning about the knowledge and belief of agents. This book provides a broad introduction to the subject, along with many exercises and their solutions. The authors begin by presenting the necessary apparatus from mathematics and logic, including Kripke semantics and the well-known modal logics K, T, S4 and S5. Then they turn to applications in the context of distributed systems and (...) artificial intelligence. These include the notions of common knowledge, distributed knowledge, explicit and implicit belief, the interplays between knowledge and time, and knowledge and action, as well as a graded (or numerical) variant of the epistemic operators. The authors also discuss extensively the problem of logical omniscience. They cover Halpern & Moses' theory of honest formulas, and they make a digression into the realm of nonmonotonic reasoning and preferential entailment. They discuss Moore's autoepistemic logic, together with Levesque's related logic of "all I know". Furthermore, they show how one can base default and counterfactual reasoning on epistemic logic. Graduate students in philosophy or in computer science, especially those with an interest in AI, will find this book useful. (shrink)

A useful logic in which to specify normative system behaviour, deontic logic has a broad spectrum of possible applications within the field: from legal expert systems to natural language processing, database integrity to electronic contracting and the specification of fault-tolerant software.

Many philosophers are convinced that rationality dictates that one’s overall set of intentions be consistent. The starting point and inspiration for our study is Bratman’s planning theory of intentions. According to this theory, one needs to appeal to the fulfilment of characteristic planning roles to justify norms that apply to our intentions. Our main objective is to demonstrate that one can be rational despite having mutually inconsistent intentions. Conversely, it is also shown that one can be irrational despite having a (...) consistent overall set of intentions. To overcome this paradox, we argue that it is essential for a successful planning system that one’s intentions are practically consistent rather than being consistent or applying an aggregation procedure. Our arguments suggest that a new type of norm is needed: whereas the consistency requirement focuses on rendering the contents of one’s intentions consistent, our new practical consistency requirement demands that one’s intentions be able to simultaneously and unconditionally guide one’s action. We observe that for intentions that conform to the ‘own-action condition’, the practical consistency requirement is equivalent to the traditional consistency requirement. This implies that the consistency requirement only needs to be amended in scenarios of choice under uncertainty. (shrink)

In social interactions, it is common for individuals to possess different amounts of knowledge about a specific transaction, and those who are more knowledgeable might perform opportunistic behavior to others in their interest, which promotes their value but demotes others’ value. Such a typical social behavior is called opportunistic behavior. In this paper, we propose a formal account of opportunism based on the situation calculus. We first propose a model of opportunism that only considers a single action between two agents, (...) and then extend it to multiple actions and incorporate social context in the model. A simple example of selling a broken cup is used to illustrate our models. Through our models, we can have a thorough understanding of opportunism. (shrink)

We present an epistemic default logic, based on the metaphore of a meta-level architecture. Upward reflection is formalized by a nonmonotonic entailment relation, based on the objective facts that are either known or unknown at the object level. Then, the meta (monotonic) reasoning process generates a number of default-beliefs of object-level formulas. We extend this framework by proposing a mechanism to reflect these defaults down. Such a reflection is seen as essentially having a temporal flavour: defaults derived at the meta-level (...) are projected as facts in a next object level state. In this way, we obtain temporal models for default reasoning in meta-level formalisms which can be conceived as labeled branching trees. Thus, descending the tree corresponds to shifts in time that model downward reflection, whereas the branching of the tree corresponds to ways of combining possible defaults. All together, this yields an operational or procedural semantics of reasoning by default, which admits one to reason about it by means of branching-time temporal logic. Finally, we define sceptical and credulous entailment relations based on these temporal models and we characterize Reiter extensions in our semantics. (shrink)

The aim of the work is to provide a language to reason about Closed Interactions, i.e. all those situations in which the outcomes of an interaction can be determined by the agents themselves and in which the environment cannot interfere with they are able to determine. We will see that two different interpretations can be given of this restriction, both stemming from Pauly Representation Theorem. We will identify such restrictions and axiomatize their logic. We will apply the formal tools to (...) reason about games and their regulation. (shrink)

We present a model-theoretic approach for reasoning about security protocols, applying recent insights from dynamic epistemic logics. This enables us to describe exactly the subsequent epistemic states of the agents participating in the protocol, using Kripke models and transitions between these based on updates of the agent's beliefs associated with steps in the protocol. As a case study we will consider the SRA Three Pass protocol and discuss the Wide-Mouthed Frog protocol.

To adequately deal with unpredictable and dynamic environments, normative frameworks typically deployed in mechanisms for modifying the norms at runtime are crucial. We present the syntax and operational semantics of programming constructs to facilitate runtime norm modification, allowing a programmer to specify when and how the norms may be changed by external agents or by the normative mechanism. The norms take on the form of conditional obligations and prohibitions, instantiating obligations and prohibitions. We present rule-based constructs for runtime modification of (...) the norms and their instances, and a mechanism for automatically updating the instances when their underlying norms change. Moreover, we investigate a mechanism for avoiding norm conflicts. (shrink)

This paper formalizes part of a well-known psychological model of emotions. In particular, the logical structure underlying the conditions that trigger emotions are studied and then hierarchically organized. The insights gained therefrom are used to guide a formalization of emotion triggers, which proceeds in three stages. The first stage captures the conditions that trigger emotions in a semiformal way, i.e., without committing to an underlying formalism and semantics. The second stage captures the main psychological notions used in the emotion model (...) in dynamic doxastic logic. The third stage introduces a BDI-based framework (belief–desire–intention) with achievement goals, which is used to firmly ground the preceding stages. The result is a formalization of emotion triggers for BDI agents with achievement goals. The idea of proceeding in these stages is to provide different levels of commitment to formalisms, so that it remains relatively easy to extend or replace the used formalisms without having to start from scratch. Finally, we show that the formalization renders properties of emotions that are in line with the psychological model on which it is based. (shrink)

We demonstrate ways to incorporate nondeterminism in a system designed to formalize the reasoning of agents concerning their abilities and the results of the actions that they may perform. We distinguish between two kinds of nondeterministic choice operators: one that expresses an internal choice, in which the agent decides what action to take, and one that expresses an external choice, which cannot be influenced by the agent. The presence of abilities in our system is the reason why the usual approaches (...) towards nondeterminism cannot be used here. The semantics that we define for nondeterministic actions is based on the idea that composite actions are unravelled in the strings of atomic actions and tests that constitute them. The main notions used in defining this semantics are finite computation sequences and finite computation runs of actions. The results that we obtain meet our intuitions regarding events and abilities in the presence of nondeterminism. (shrink)

In Multi Agent Systems it is often the case that individual preferences are not compatible and coalitions compete to achieve a given result. The paper presents a language to talk about the conflict between coalitional choices and it expresses deontic notions to evaluate them. We will be specifically concerned with cases where the collective perspective is at odds with the individual perspective.

We give a model for iterated belief change in multi-agent systems. The formal tool we use for this is a combination of modal and dynamic logic. Two core notions in our model are the expansion of the knowledge and beliefs of an agent, and the processing of new information. An expansion is defined as the change in the knowledge and beliefs of an agent when it decides to believe an incoming formula while holding on to its current propositional beliefs. To (...) prevent our agents from forming inconsistent beliefs they do not expand with every piece of information they receive. Instead, our agents remember their original beliefs and every piece of information they receive. After every receipt of information they decide which subset of the received information should be incorporated into their original beliefs. This procedure is called the processing of new information. We show that our model of belief update behaves in an intuitive way and that it is not sensitive to criticism on comparable models. (shrink)

We demonstrate ways to incorporate nondeterminism in a system designed to formalize the reasoning of agents concerning their abilities and the results of the actions that they may perform. We distinguish between two kinds of nondeterministic choice operators: one that expresses an internal choice, in which the agent decides what action to take, and one that expresses an external choice, which cannot be influenced by the agent. The presence of abilities in our system is the reason why the usual approaches (...) towards nondeterminism cannot be used here. The semantics that we define for nondeterministic actions is based on the idea that composite actions are unravelled in the strings of atomic actions and tests that constitute them. The main notions used in defining this semantics are finite computation sequences and finite computation runs of actions. The results that we obtain meet our intuitions regarding events and abilities in the presence of nondeterminism. (shrink)

This article discusses relations among the multiple levels of analysis present in macro-sociological explanation—i.e., relations of individual, structural, and institutional processes. It also criticizes the doctrinal insistence upon single-level individualistic explanation found in some prominent contemporary sociological theory. For illustrative material the article returns to intellectual uses of Weber's "Protestant Ethic thesis," showing how an artificial version has been employed as a kind of proof text for the alleged scientific necessity of individualist explanation. Our alternative exposition renders the discussion of (...) Protestantism and capitalism in an explicitly multilevel way, distinguishing possible individual-level, social-organizational, and institutional linkages. The causal processes involved are distinct ones, with the more structural and institutional forms neither captured nor attainable by individual-level thinking. We argue more generally that "methodological individualisms" confuse issues of explanation with issues about microfoundations. This persistent intellectual conflation may be rooted in the broader folk models of liberal individualism. (shrink)

Much social theory takes for granted the core conceit of modern culture, that modern actors-individuals, organizations, nation states-are autochthonous and natural entities, no longer really embedded in culture. Accordingly, while there is much abstract metatheory about "actors" and their "agency," there is arguably little theory about the topic. This article offers direct arguments about how the modern (European, now global) cultural system constructs the modern actor as an authorized agent for various interests via an ongoing relocation into society of agency (...) originally located in transcendental authority or in natural forces environing the social system. We see this authorized agentic capability as an essential feature of what modern theory and culture call an "actor," and one that, when analyzed, helps greatly in explaining a number of otherwise anomalous or little analyzed features of modern individuals, organizations, and states. These features include their isomorphism and standardization, their internal decoupling, their extraordinarily complex structuration, and their capacity for prolific collective action. (shrink)

For centuries, the processes of social differentiation associated with Modernity have often been thought to intensify the need for site-specific forms of role training and knowledge production, threatening the university’s survival either through fragmentation or through failure to adapt. Other lines of argument emphasize the extent to which the Modern system creates and relies on an integrated knowledge system, but most of the literature stresses functional differentiation and putative threats to the university. And yet over this period the university has (...) flourished. In our view, this seeming paradox is explained by the fact that modern society rests as much on universalistic cosmological bases as it does on differentiation. The university expands over recent centuries because – as it has from its religious origins – it casts cultural and human materials in universalistic terms. Our view helps explain empirical phenomena that confound standard accounts: the university’s extraordinary expansion and global diffusion, its curricular and structural isomorphism, and its relatively unified structure. All of this holds increasingly true after World War II, as national state societies made up of citizens are increasingly embedded in a world society constituted of empowered individuals. The redefinition of society in global and individual terms reduces nationally bounded models of nature and culture, extends the pool of university beneficiaries and investigators, and empowers the human persons who are understood to root it all. The changes intensify universalization and the university’s rate of worldwide growth. For the university’s knowledge and “knowers,” and for the pedagogy that joins them together, the implications are many. The emerging societal context intensifies longstanding processes of cultural rationalization and ontological elaboration, yielding great expansions in what can and should be known, and in who can and should know. These changes in turn alter the menu of approved techniques for joining knowledge and knower as one. The “knowledge society” that results is distinguished by the extraordinary degree to which the university is linked to society. But it is also distinguished by the degree to which society is organized around the university’s abstracted and universalized understandings of the world and its degree-certified graduates. (shrink)

This Handbook defines, illustrates, and challenges the field of environmental political theory. Through a broad range of approaches, it shows how scholars have used concepts, methods, and arguments from political theory and closely related disciplines to address contemporary environmental problems. Topics include the relationship of EPT to traditions of political thought; EPT conceptualizations of nature, the environment, community, justice, responsibility, rights, and flourishing; explorations of the structures that constrain or enable the achievement of environmental ends; and analyses of methods for (...) fostering environmental change. (shrink)

In recent decades, the individual has become more and more central in both national and world cultural accounts of the operation of society. This continues a long historical process, intensified by the consolidation of a more global polity and the weakening of the primordial sovereignty of the national state. Increasingly, society is culturally rooted in the natural, historical, and spiritual worlds through the individual, rather than through corporate entities or groups. The shift has produced a proliferation and specification of individual (...) roles, accounting for what individuals do in society. It has also produced an expansion in recognized individual personhood, accounting for who individuals are in the extrasocial cosmos and fueling elaborated personal tastes and preferences. Where it has been contested, the shift to the individual has also produced a rise in specializing identities. These offer accounts of individuals' distinctive linkages to the cosmos, and they serve to bolster individual claims to standard roles and personhood. Over time, specializing identities tend to get absorbed into roles and personhood. And in turn, expanded roles and personhood provide further bases for specializing identity claims. Because many theorists mischaracterize the relationship of specializing identities to roles and personhood, the literature often overemphasizes the anomic character of the identity explosion and the closeness of the coupling between social roles and identity claims. On the contrary, specializing identities tend to be edited to remain within general rules of individual personhood and to be disconnected from the obligations involved in institutionalized roles. (shrink)

Feldman and Turner defend the making of so-called ‘NIMBY’ claims as ethically justifiable. They do so while confronting a case—Robert F. Kennedy Jr.'s opposition to the Cape Wind Project in Nantuck...

Darrel Moellendorf places hope at the core of his call for climate-change vision and action, positing a ‘hopeful vision of a sustainable and prosperous world’ committed to ‘green growth’ – along th...

Feldman and Turner defend the making of so-called ‘NIMBY’ claims as ethically justifiable. They do so while confronting a case—Robert F. Kennedy Jr.'s opposition to the Cape Wind Project in Nantuck...

An absolutist concept of property has the power to shape and constrain the public imagination. Libertarian theorists normatively embrace this concept. Yet its influence extends far beyond these proponents, shaping the views of an otherwise diverse array of theorists and activists. This limits the ability of environmentalists, among others, to respond coherently to challenges from property rights advocates in the U.S. I sketch an alternative concept--rooted in practice--that understands private property as necessarily embedded in social and ecological relations, rather than (...) constrained by these relations. I argue that this concept can prefigure a more robust environmentalism. (shrink)

This essay briefly describes a few of the problems associated with using personhood language to defend the right to life of the pre‐implantation embryo. Arguing that an immaterial soul explains the personal identity of an embryo is problematic for many people because there is no apparent spiritual activity in the unborn. While some scholars argue that the embryo has the potential to act as an adult person and thus should be protected from harm, others contend that potentiality alone is insufficient (...) reason to ascribe special moral worth to the embryo in utero. For Thomas Aquinas, the soul is not only the life‐principle that organizes the human body, but it is also that by which the human being thinks and wills. By making suitable corrections to Aristotle's hylomorphic depiction of the soul–body relation, I suggest that a rational soul must be present from the moment of conception and that it is at the service of the person. What is of critical importance here is to accept that a human being is present from the moment of conception, something the vast majority of embryologists maintain, notwithstanding the inveiglement of those who state that the pre‐implantation blastocyst is simply a disorganized clump of cells. (shrink)

Curriculum programmes are conventionally expected to produce outcomes or specific results demonstrated in the performance of learners. Usually the intended outcomes are expressed in the conceptual framework or design of the curriculum. Programme assessment is intended to collect data that will provide evidence for these effects on learners.

In this article I present the Son - Spirit relationship in Christ as the secret to the connection between immanent/economic trinitarian dichotomies without compromising the reality of Christ's human nature. I suggest thatthe Spirit bridges the gap separating God and human beings by linking the inaugurated eschatological present with the future fulfillment of our nascent condition as children of God in Christ. The key notion for understanding God's self-communication rests with the unique role of the Spirit of Christ, who, in (...) the economy, anoints believers in the Son and establishes a real relation between them and God the Father. In effect, the Spirit divinizes all who enter into the risen body of Christ, by activating and bringing to perfection the natural filiation of the Son that is in them by virtue of baptism. This divine gift of participation in the immanent trinitarian life of the Son enables the believer not only to know and love God in a divine way but also to love others as God loves them. (shrink)

This essay briefly describes a few of the problems associated with using personhood language to defend the right to life of the pre‐implantation embryo. Arguing that an immaterial soul explains the personal identity of an embryo is problematic for many people because there is no apparent spiritual activity in the unborn. While some scholars argue that the embryo has the potential to act as an adult person and thus should be protected from harm, others contend that potentiality alone is insufficient (...) reason to ascribe special moral worth to the embryo in utero. For Thomas Aquinas, the soul is not only the life‐principle that organizes the human body, but it is also that by which the human being thinks and wills. By making suitable corrections to Aristotle's hylomorphic depiction of the soul–body relation, I suggest that a rational soul must be present from the moment of conception and that it is at the service of the person. What is of critical importance here is to accept that a human being is present from the moment of conception, something the vast majority of embryologists maintain, notwithstanding the inveiglement of those who state that the pre‐implantation blastocyst is simply a disorganized clump of cells. (shrink)

Creative Intelligence: Essays in the Pragmatic Attitude represents an attempt at intellectual cooperation. No effort has been made, however, to attain unanimity of belief nor to proffer a platform of "planks" on which there is agreement. The consensus represented lies primarily in outlook, in conviction of what is most likely to be fruitful in method of approach. As the title page suggests, the volume presents a unity in attitude rather than a uniformity in results. Consequently each writer is definitively responsible (...) only for his own essay. The reader will note that the Essays endeavor to embody the common attitude in application to specific fields of inquiry which have been historically associated with philosophy rather than as a thing by itself. Beginning with philosophy itself, subsequent contributions discuss its application to logic, to mathematics, to physical science, to psychology, to ethics, to economics, and then again to philosophy itself in conjunction with esthetics and religion. The reader will probably find that the significant points of agreement have to do with the ideas of the genuineness of the future, of intelligence as the organ for determining the quality of that future so far as it can come within human control, and of a courageously inventive individual as the bearer of a creatively employed mind. (shrink)