This is a welcome reprint of a book that continues to grow in importance.

Machine generated contents note: Essay 1.

Although the change of beliefs in the face of new information has been widely studied with some success, the revision of other mental states has received little attention from the theoretical perspective. In particular, intentions are widely recognised as being a key attitude for rational agents, and while several formal theories of intention have been proposed in the literature, the logic of intention revision has been hardly considered. There are several reasons for this: perhaps most importantly, intentions are very closely (...) connected with other mental states—in particular, beliefs about the future and the abilities of the agent. So, we cannot study them in isolation. We must consider the interplay between intention revision and the revision of other mental states, which complicates the picture considerably. In this paper, we present some first steps towards a theory of intention revision. We develop a simple model of an agent’s mental states, and define intention revision operators. Using this model, we develop a logic of intention dynamics, and then investigate some of its properties. (shrink)

Rational agents are important objects of study in several research communities, including economics, philosophy, cognitive science, and most recently computer science and artificial intelligence. Crudely, a rational agent is an entity that is capable of acting on its environment, and which chooses to act in such a way as to further its own best interests. There has recently been much interest in the use of mathematical logic for developing formal theories of such agents. Such theories view agents as practical reasoning (...) systems, deciding moment by moment which action to perform next, given the beliefs they have about the world and their desires with respect to how they would like the world to be. In this article, we survey the state of the art in developing logical theories of rational agency. Following a discussion on the dimensions along which such theories can vary, we briefly survey the logical tools available in order to construct such theories. We then review and critically assess three of the best known theories of rational agency: Cohen and Levesque's intention logic, Rao and Georgeff's BDI logics, and the KARO framework of Meyer et al. We then discuss the various roles that such logics can play in helping us to engineer rational agents, and conclude with a discussion of open problems. (shrink)

Intentions are an important concept in Artificial Intelligence and Cognitive Science. We present a formal theory of intentions and beliefs based on Discourse Representation Theory that captures many of their important logical properties. Unlike possible worlds approaches, this theory does not assume that agents are perfect reasoners, and gives a realistic view of their internal architecture; unlike most representational approaches, it has an objective semantics, and does not rely on an ad hoc labeling of the internal states of agents. We (...) describe a minimal logic for intentions and beliefs that is sound and complete relative to our semantics. We discuss several additional axioms, and the constraints on the models that validate them. (shrink)

This essay has two goals. The first is to define the behavioristic study of natural events and to classify behavior. The second is to stress the importance of the concept of purpose.Given any object, relatively abstracted from its surroundings for study, the behavioristic approach consists in the examination of the output of the object and of the relations of this output to the input. By output is meant any change produced in the surroundings by the object. By input, conversely, is (...) meant any event external to the object that modifies this object in any manner. (shrink)

This paper presents a model of persuasion in terms of goals and beliefs. Among the various ways to influence people, that is, to raise or lower the likelihood for them to pursue some goal, ranging from threat to suggestion, persuasion is viewed as a case of communicative non-coercive goal hooking. A persuader leads a persuadee to pursue some goal out of a free choice, i.e., by convincing him/her that the proposed goal is useful for some other goal that the persuadee (...) already has. It is argued that the Aristotelian persuasive strategies of logos, ethos and pathos (rational argumentation, the speaker¿s credibility and reliability, and the appeal to emotion) are always present in every persuasive discourse, and that they are exploited to raise the value of the goal proposed and to strengthen the believability of the link between it and the persuadee¿s previous goals. The paper proposes an analysis of discourse in terms of a hierarchy of goals as a tool to single out these strategies within the discourse structure. By applying this model to different kinds of persuasive messages (political discourse, advertising, dialogues in the health domain), it shows how, in the fragments presented, this kind of analysis allows to clarify the relationships between the persuader¿s and the persuadee¿s goals and to elucidate how much and how directly the persuader appeals to logos, ethos and pathos in his/her discourse. (shrink)

Although the change of beliefs in the face of new information has been widely studied with some success, the revision of other mental states has received little attention from the theoretical perspective. In particular, intentions are widely recognised as being a key attitude for rational agents, and while several formal theories of intention have been proposed in the literature, the logic of intention revision has been hardly considered. There are several reasons for this: perhaps most importantly, intentions are very closely (...) connected with other mental states—in particular, beliefs about the future and the abilities of the agent. So, we cannot study them in isolation. We must consider the interplay between intention revision and the revision of other mental states, which complicates the picture considerably. In this paper, we present some first steps towards a theory of intention revision. We develop a simple model of an agent’s mental states, and define intention revision operators. Using this model, we develop a logic of intention dynamics, and then investigate some of its properties. (shrink)

This paper explores principles governing the rational balance among an agent's beliefs, goals, actions, and intentions. Such principles provide specifications for artificial agents, and approximate a theory of human action (as philosophers use the term). By making explicit the conditions under which an agent can drop his goals, i.e., by specifying how the agent is committed to his goals, the formalism captures a number of important properties of intention. Specifically, the formalism provides analyses for Bratman's three characteristic functional roles played (...) by intentions [7, 9], and shows how agents can avoid intending all the foreseen side-effects of what they actually intend. Finally, the analysis shows how intentions can be adopted relative to a background of relevant beliefs and other intentions or goals. By relativizing one agent's intentions in terms of beliefs about another agent's intentions (or beliefs'), we derive a preliminary account of interpersonal commitments. (shrink)

What happens to our conception of mind and rational agency when we take seriously future-directed intentions and plans and their roles as inputs into further practical reasoning? The author's initial efforts in responding to this question resulted in a series of papers that he wrote during the early 1980s. In this book, Bratman develops further some of the main themes of these essays and also explores a variety of related ideas and issues. He develops a planning theory of intention. Intentions (...) are treated as elements of partial plans of action. These plans play basic roles in practical reasoning, roles that support the organization of our activities over time and socially. Bratman explores the impact of this approach on a wide range of issues, including the relation between intention and intentional action, and the distinction between intended and expected effects of what one intends. (shrink)

This collection of essays by one of the most prominent and internationally respected philosophers of action theory is concerned with deepening our understanding of the notion of intention. In Bratman's view, when we settle on a plan for action we are committing ourselves to future conduct in ways that help support important forms of coordination and organization both within the life of the agent and interpersonally. These essays enrich that account of commitment involved in intending, and explore its implications for (...) our understanding of temptation and self-control, shared intention and shared cooperative activity, and moral responsibility. The essays offer extensive discussions of related views by, among others, Donald Davidson, Hector-Neri Castañeda, Christine Korsgaard, Harry Frankfurt, and P. F. Strawson. This collection will be a valuable resource for a wide range of philosophers and their students. (shrink)

My goal is to define intending. I defend the view that believing and desiring something are necessary for intending it. They are not sufficient, however, for some things we both expect and want (e.g., the sun to rise tomorrow) are unintendable. Restricting the objects of intention to our own future actions is unwarranted and unhelpful. Rather, the belief involved in intending must be based on the desire in a certain way. En route, I argue that expected but unwanted consequences are (...) not intended, examine the two senses of "desire," distinguish intending from being willing, and relate intending to a variety of other propositional at? titudes. (shrink)

what is now the mainstream view as to the best way forward in the dream of engineering reliable software systems out of autonomous agents. The way of using formal logics to specify, implement and verify distributed systems of interacting units using a guiding analogy of beliefs, desires and intentions. The implicit message behind the book is this: Distributed Artificial Intelligence (DAI) can be a respectable engineering science. It says: we use sound formal systems; can cite established philosophical foundations; and will (...) be able to build reliable and flexible software systems. (shrink)

This is the text of The Lindley Lecture for 1967, given by Wilfrid Sellars (1912-1989), an American philosopher.