In a recent paper, Negri and Pavlović (Studia Logica 1–35, 2020) have formulated a decidable sequent calculus for the logic of agency, specifically for a deliberative see-to-it-that modality, or dstit. In that paper the adequacy of the system is demonstrated by showing the derivability of the axiomatization of dstit from Belnap et al. (Facing the future: agents and choices in our indeterminist world. Oxford University Press, Oxford, 2001). And while the influence of the latter book on the study (...) of logics of agency cannot be overstated, we note that this is not the only axiomatization of that modality available. In fact, an earlier (and arguably purer) one was offered in Xu (J Philosophical Logic 27(5):505–552, 1998). In this article we fill this lacuna by proving that this alternative axiomatization is likewise readily derivable in the system of Negri and Pavlović (Studia Logica 1–35, 2020). (shrink)

The aim of this paper, is to provide a logical framework for reasoning about actions, agency, and powers of agents and coalitions in game-like multi-agent systems. First we define our basic Dynamic Logic of Agency ( ). Differently from other logics of individual and coalitional capability such as Alternating-time Temporal Logic (ATL) and Coalition Logic, in cooperation modalities for expressing powers of agents and coalitions are not primitive, but are defined from more basic dynamic (...) class='Hi'>logic operators of action and (historic) necessity. We show that STIT logic can be reconstructed in . We then extend with epistemic operators, which allows us to distinguish capability and power. We finally characterize the conditions under which agents are aware of their capabilities and powers. (shrink)

The paper presents an infinite hierarchy of sound and complete axiomatic systems for Two-Dimensional Modal Tense Logic with Historical Necessity, Agents and Acts. A main novelty of these logics is their capacity to represent formally (i) basic action-sentences asserting that such and such an act is performed/omitted by an agent, as well as (ii) causative action-sentences asserting that by performing/omitting a certain act, an agent causes that such and such a state-of-affairs is realized (e.g. comes about/ceases/remains/remains absent). We illustrate (...) how the formal machinery of our systems can be used to reconstruct a number of interesting ideas in the Logic of Agency and Action that have been proposed by authors like von Wright, von Kutschera, Belnap and Segerberg. (shrink)

We continue the work initiated in Herzig and Lorini (J Logic Lang Inform, in press) whose aim is to provide a minimalistic logical framework combining the expressiveness of dynamic logic in which actions are first-class citizens in the object language, with the expressiveness of logics of agency such as STIT and logics of group capabilities such as CL and ATL. We present a logic called ( Deterministic Dynamic logic of Agency ) which supports reasoning (...) about actions and joint actions of agents and coalitions, and agentive and coalitional capabilities. In it is supposed that, once all agents have selected a joint action, the effect of this joint action is deterministic. In order to assess we prove that it embeds Coalition Logic. We then extend with modal operators for agents’ preferences, and show that the resulting logic is sufficiently expressive to capture the game-theoretic concepts of best response and Nash equilibrium. (shrink)

This light piece reflects on analogies between two often disjoint streams of research: the logical semantics and pragmatics of natural language and dynamic logics of general information-driven agency. The two areas show significant overlap in themes and tools, and yet, the focus seems subtly different in each, defying a simple comparison. We discuss some unusual questions that emerge when the two are put side by side, without any pretense at covering the whole literature or at reaching definitive conclusions.

This paper deals with structures ${\langle{\bf T}, I\rangle}$ in which T is a tree and I is a function assigning each moment a partition of the set of histories passing through it. The function I is called indistinguishability and generalizes the notion of undividedness. Belnap’s choices are particular indistinguishability functions. Structures ${\langle{\bf T}, I\rangle}$ provide a semantics for a language ${\mathcal{L}}$ with tense and modal operators. The first part of the paper investigates the set-theoretical properties of the set of indistinguishability (...) classes, which has a tree structure. The significant relations between this tree and T are established within a general theory of trees. The aim of second part is testing the expressive power of the language ${\mathcal{L}}$ . The natural environment for this kind of investigations is Belnap’s seeing to it that (stit). It will be proved that the hybrid extension of ${\mathcal{L}}$ (with a simultaneity operator) is suitable for expressing stit concepts in a purely temporal language. (shrink)

A sequent calculus methodology for systems of agency based on branching-time frames with agents and choices is proposed, starting with a complete and cut-free system for multi-agent deliberative STIT; the methodology allows a transparent justification of the rules, good structural properties, analyticity, direct completeness and decidability proofs.

We present a Hilbert style axiomatization and an equational theory for reasoning about actions and capabilities. We introduce two novel features in the language of propositional dynamic logic, converse as backwards modality and abstract processes specified by preconditions and effects, written as \({\varphi \Rightarrow \psi}\) and first explored in our recent paper (Hartonas, Log J IGPL Oxf Univ Press, 2012), where a Gentzen-style sequent calculus was introduced. The system has two very natural interpretations, one based on the familiar relational (...) semantics and the other based on type semantics, where action terms are interpreted as types of actions (sets of binary relations). We show that the proof systems do not distinguish between the two kinds of semantics, by completeness arguments. Converse as backwards modality together with action types allow us to produce a new purely equational axiomatization of Dynamic Algebras, where iteration is axiomatized independently of box and where the fixpoint and Segerberg induction axioms are derivable. The system also includes capabilities operators and our results provide then a finitary Hilbert-style axiomatization and a decidable system for reasoning about agent capabilities, missing in the KARO framework. (shrink)

We study a fragment of Intuitionistic Linear Logic combined with non-normal modal operators. Focusing on the minimal modal logic, we provide a Gentzen-style sequent calculus as well as a semantics in terms of Kripke resource models. We show that the proof theory is sound and complete with respect to the class of minimal Kripke resource models. We also show that the sequent calculus allows cut elimination. We put the logical framework to use by instantiating it as a (...) class='Hi'>logic of agency. In particular, we apply it to reason about the resource-sensitive use of artefacts. (shrink)

Recent theories of agency (sees to it that) of Nuel Belnap and Michael Perloff are examined, particularly in the context of an early proposal of the author.

Hegel’s Logic reveals an insightful and subtle engagement with the traditional problem of free will as it emerges from our basic commitment to the explicability of the world. While the dominant current interpretations of Hegel’s theory of agency find little of significance in the Logic and suggest that Hegel avoided the traditional problem, Yeomans argues both that the problem is unavoidable, and that the two versions of the Logic fruitfully engage the tensions between explicability and both (...) the control and alternate possibilities constitutive of free agency. In particular, Yeomans examines Hegel’s response to three different versions of the principle of sufficient reason that have historically seemed to make free will problematic. The central three chapters take up each of these versions in turn. For each, Yeomans first explores the nature of its challenge to free will with glances both at Hegel’s precursors and contemporaries and at the philosophy of action of our own time. Then Yeomans delves into the arguments of Hegel’s Logic to see how he construed the problematic concepts in question. Finally, Yeomans returns to the issue of free will to bring Hegel’s interpretations of the concepts in the Logic together with elements of his moral psychology from his practical philosophy both to show how the problem of free will can be resolved, and to trace in outline the shape of free will that such a resolution produces. The key connection between the Logic’s reflections on the form of explanation and the practical philosophy’s theory of the will is that both attempt to do justice to the mutual necessity of self-determination and external influence. (shrink)

We use a deontic logic of collective agency to study reducibility questions about collective agency and collective obligations. The logic that is at the basis of our study is a multi-modal logic in the tradition of *stit* logics of agency. Our full formal language has constants for collective and individual deontic admissibility, modalities for collective and individual agency, and modalities for collective and individual obligations. We classify its twenty-seven sublanguages in terms of their (...) expressive power. This classification enables us to investigate reducibility relations between collective deontic admissibility, collective agency, and collective obligations, on the one hand, and individual deontic admissibility, individual agency, and individual obligations, on the other. (shrink)

In this paper we show that the Hilbert system of agency and ability presented by Dag Elgesem is incomplete with respect to the intended semantics. We argue that completeness result may be easily regained. Finally, we shortly discuss some issues related to the philosophical intuition behind his approach. This is done by examining Elgesem's modal logic of agency and ability using semantics with different flavours.

A prominent issue in mainstream epistemology is the controversy about doxastic obligations and doxastic voluntarism. In the present paper it is argued that this discussion can benefit from forging links with formal epistemology, namely the combined modal logic of belief, agency, and obligation. A stit-theory-based semantics for deontic doxastic logic is suggested, and it is claimed that this is helpful and illuminating in dealing with the mentioned intricate and important problems from mainstream epistemology. Moreover, it is argued (...) that this linking is of mutual benefit. The discussion of doxastic voluntarism directs the attention of doxastic logicians to the notion of belief formation and thus to dynamic aspects of beliefs that have hitherto been neglected. The development of a formal language and semantics for ascriptions of belief formation may contribute to clarifying the contents and the implications of voluntaristic claims. A simple observation concerning other-agent nestings of stit-operators, for instance, may help illuminating the notions of making belief and responsibility for beliefs of others. In this way, stit-theory may serve as a bridge between mainstream and formal epistemology. (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)

We present a logic of agency called LAE whose language includes propositional constants for actions and expectations. The logic is based on Von Wright’s theory of agency in general and his analysis of instrumentality in particular. An axiomatization of the logic, including an independence of agents axiom, is provided and soundness and completeness are shown with respect to its intended class of frames. The framework of LAE will allow us to formally define a manifold of (...) concepts involved in agency theories, including Von Wright’s four elementary forms of action, the notion of forbearance and notions of instrumentality that make reference to an agent’s expectations. (shrink)

Taking the perspective of knowledge representation, we introduce a simple logic of agency where the agents’ actions are described by their precondition and effects and whose semantics is based on the concept of attempt. We give its syntax, semantics, and axiomatics and discuss the relation with other proposals, in particular Belnap and Horty’s ‘branching time and agent choice’ semantics (BT+AC) and Czelakowski’s relational semantics.

A vital step to successfully orienting Deleuze with biosemiotics (and theories of biological complexity overall) is to discover a coherent scientific throughline in his work that also accounts for the aesthetic/creative dimension of his philosophy. This requires the heterodox move (from a Deleuzean point of view) of giving priority to the organism. I argue that Deleuze’s treatment of the organism does more than signal a superficial relation to biological complexity theory that, as a result of his nuanced take on the (...) matter, undermines the value of the organic body to his system. Instead, we can recognize a working theory of autopoiesis in the early Deleuze that scaffolds as well as substantiates his later ethological and biosemiotic observations and reveals a definite, albeit minimal, notion of subjectivity in his work. Most importantly, reorienting his logic of sense as a logic of _sense-making_, or the context-dependent signification between system and environment (Thompson, 2007 ), allows us to begin the work of mining a scientific throughline in Deleuze’s work akin to biological complexity theory that is of value to both Deleuze studies and biosemiotics. (shrink)

A major problem threatens Deleuze’s project in The Logic of Sense. He makes an ontological distinction between events and substances, but he then collapses a crucial distinction between two kinds of events, namely, actions and mere occurrences. Indeed, whereas actions are commonly differentiated from mere occurrences with reference to their causal dependence on the intentions of their agents, Deleuze asserts a strict ontological distinction between the realm of causes and the realm of events, and holds that events of all (...) types are incorporeal happenings which are inseparable from expressed sense. For Deleuze, what counts as one’s action thus does not depend on one’s intention, but rather on a process of “making sense” of that action. Nevertheless, Deleuze continues to speak of the need to “will” the event. In order to resolve this apparent contradiction, I will read a conception of “expressive agency” into The Logic of Sense. (shrink)

O propósito desse artigo é fornecer um tratamento formal para um tipo de ação até o momento negligenciada nas lógicas modais filosóficas da ação: ação em plano. Ao fazer isso nós seguimos a abordagem padrão nas lógicas modais da ação exemplificados pelos trabalhos de Belnap, Chellas and Pörn. Como nós acreditamos que existe uma relação forte entre plano, tempo e indeterminismo, nós usamos a teoria do tempo ramificado para investigar as características básicas da ação em plano. Além de introduzir uma (...) semântica do tempo ramificado, nós também apresentamos um cálculo correto e completo com relação a essa semântica. DOI:10.5007/1808-1711.2010v14n3p421. (shrink)

We introduce the logic LRC, designed to describe and reason about agents’ abilities and capabilities in using resources. The proposed framework bridges two—up to now—mutually independent strands of literature: the one on logics of abilities and capabilities, developed within the theory of agency, and the one on logics of resources, motivated by program semantics. The logic LRC is suitable to describe and reason about key aspects of social behaviour in organizations. We prove a number of properties enjoyed (...) by LRC and its associated analytic calculus. These results lay at the intersection of the algebraic theory of unified correspondence and the theory of multitype calculi in structural proof theory. Case studies are discussed which showcase several ways in which this framework can be extended and enriched while retaining its basic properties, so as to model an array of issues, both practically and theoretically relevant, spanning from planning problems to the logical foundations of the theory of organizations. (shrink)

Aim of the present paper is to provide a formal characterization of various different notions of responsibility within groups of agents (Who did that? Who gets the blame? Who is accountable for that? etc.). To pursue this aim, the papers proposes an organic analysis of organized collective agency by tackling the issues of organizational structure, role enactment, organizational activities, task-division and task-allocation. The result consists in a semantic framework based on dynamic logic in which all these concepts can (...) be represented and in which various notions of responsibility find a formalization. The background motivation of the work consists in those responsibility-related issues which are of particular interest for the theory and development of multi-agent systems. (shrink)

Imagination has recently attracted considerable attention from epistemologists and is recognized as a source of belief and even knowledge. One remarkable feature of imagination is that it is often and typically agentive: agents decide to imagine. In cases in which imagination results in a belief, the agentiveness of imagination may be taken to give rise to indirect doxastic control and epistemic responsibility. This observation calls for a proper understanding of agentive imagination. In particular, it calls for the development of a (...) semantics of imagination ascriptions. In the present paper an earlier suggestion by Ilkka Niiniluoto for a logic of imagination is considered. This proposal does not capture the agentive nature of imagination, and an alternative semantics is suggested. The new semantics combines the modal logic of agency with the neighbourhood semantics from alethic modal logic. (shrink)

Agency can be construed as both the manner in which autonomous individuals embark on particular courses of action (or inaction), and the relationship between such agents and the outcomes of the courses of action on which they embark. A promising strategy for understanding both senses of agency consists in the combination of a modal logic of agency and branching time semantics. Such is the strategy behind stit theory, the theory of agentive action developed by Nuel Belnap (...) and others. However, stit theoretic evaluations of the agentive relationship between agents and outcomes that are uncertain—due to either the presence of indeterminism, or the possible intervention of other agents—yield counterintuitive results. This paper develops a pair of alternative operators (the “act” operators) for modeling agency with respect to uncertain outcomes. Unlike the stit-theoretic model, the act-theoretic model of agency with respect to a particular state of affairs does not require that the state of affairs be realized in every possible history. If the state of affairs in fact obtains in the actual history, and its obtaining was dependent on the agent’s pursuing a particular course of action, then the agent is deemed agentive under act theory. (shrink)

Logic and philosophy of science share a long history, though contacts have gone through ups and downs. This paper is a brief survey of some major themes in logical studies of empirical theories, including links to computer science and current studies of rational agency. The survey has no new results: we just try to make some things into common knowledge.

Abstract Orthodox decision theory presupposes that agency is invested in individuals. An opposing literature allows team agency to be invested in teams whose members use distinctive modes of team reasoning. This paper offers a new conceptual framework, inspired by David Lewis's analysis of common reasons for belief, within which team reasoning can be represented. It shows how individuals can independently endorse a principle of team reasoning which prescribes acting as a team member conditional on assurance that others have (...) endorsed the same principle. It argues that there can be such assurance even when no individual has an obligation to act on team reasoning. *This paper originated in a lecture that I gave at a Colloquium on Collective Intentions at Erasmus University Rotterdam. I thank participants, and particularly Govert den Hartogh, for comments. The analysis presented in this paper is an offshoot of a larger project, which uses David Lewis's work as the starting point for a reconstruction of the foundations of game theory. That project is joint work with Robin Cubitt. The specific idea of using this approach to analyse team reasoning grew out of a discussion with Michael Bratman. My work was supported by the Leverhulme Trust. (shrink)

This book is concerned with the connection between the formal structure of agency and the formal structure of genocide. The contributors employ philosophical approaches to explore the idea of genocidal violence as a structural element in the world. Do mechanisms or structures in nation-states produce types of national citizens that are more susceptible to genocidal projects? There are powerful arguments within philosophy that in order to be the subjects of our own lives, we must constitute ourselves specifically as national (...) subjects and organize ourselves into nation states. Additionally, there are other genocidal structures of human society that spill beyond historically limited episodes. The chapters in this volume address the significance--moral, ethical, political--of the fact that our very form of agency suggests or requires these structures. The contributors touch on topics including birthright citizenship, contemporary mass incarceration, anti-black racism, and late capitalism. Logics of Genocide will be of interest to scholars and advanced students working in philosophy, critical theory, genocide studies, Holocaust and Jewish studies, history, and anthropology. (shrink)

The body of this book contains four original papers, comments, and author's replies, from a conference on the Logic of Decision and Action held at the University of Pittsburgh in March 1966. The principal authors are Herbert Simon, N. Rescher, Donald Davidson, and G. H. von Wright. Commentators are R. Ackermann, A. R. Anderson, N. D. Belnap, R. Binkley, H. N. Castañeda, R. Chisholm, J. Robison, and the late E. J. Lemmon. As appendices, there are articles by A. R. (...) Anderson "The Formal Analysis of Normative Systems," and Rescher's very brief scheme for the classifications of "actions" according to five key generic elements. Problems of decision and action are important for all philosophical critique of norms; in ethics, philosophy of science, of the social sciences, and so forth. The task of a comprehensive logic of action is to describe or prescribe the rules that govern reasoning about the occasions for action, the discovery of action alternatives, and the choice of action. In "The Logic of Heuristic Decision Making," Herbert Simon continues to support the view presented in his earlier work, that "ordinary mathematical reasoning, hence the ordinary logic of declarative statements, is all that is required," as relevant imperatives can be brought into normative systems via correspondence rules for conversion of existential statements. In "Semantic Foundations for the Logic of Preference," Rescher starts from the familiar semantical notion of a "possible world," offering the valuation-measure for such worlds as a determinant of preferabilities, and hoping to show that divergent approaches to problems of preference may be reconciled in this way. Davidson's article, "The Logical Form of Action Sentences" analyzes concepts of agency and intentionality. G. H. von Wright sees a logic of change to be necessary in order to formulate a logic of action. His essay elaborates some of the ideas in his book Norms and Action, but also gives essential modifications of his earlier views.--M. B. M. (shrink)

Free action and microphysical determination are incompatible but this is so only in virtue of a genuine conflict between microphysical determination with any active behavior. I introduce active behavior as the veridicality condition of agentive experiences and of perceptual experiences and argue that these veridicality conditions are fulfilled in many everyday cases of human and non-human behavior and that they imply the incompatibility of active behavior with microphysical determination. The main purpose of the paper is to show that the view (...) proposed about active behavior leads to a natural compromise between libertarianism and compatibilism, which avoids the flaws of both positions while preserving their central insights. (shrink)

The concept of agency, although central to many sociological debates, has remained frustratingly elusive to pin down. This article is an attempt to open up what has been called the "black box" of personal agency by distinguishing clearly between two contrasting conceptions of the phenomenon. These two conceptions are very apparent in the manner in which the concept is defined in sociological reference works, resembling as it does a similar contrast in the treatment of the concept of power. (...) The two are referred to as type 1 and type 2 or the power of agency as compared with agentic power, the essential contrast being that the first refers to an actor's ability to initiate and maintain a program of action while the second refers to an actor's ability to act independently of the constraining power of social structure. The nature of these two forms of personal agency is then illustrated by referring to material taken from Weber's essay The Protestant Ethic and the Spirit of Capitalism, this essay itself being understood as an argument that focuses on the crucial role played by an increase in the power of agency in ushering in the modern world. Finally, it is argued that these two conceptions of agency possess no given logical relationship with each other, it being perfectly possible for individuals to be possessed of considerable power of agency while lacking agentic power, and vice versa. It is therefore concluded that it is important, in all discussions of human agency, to distinguish clearly between these two forms. (shrink)

My project in the dissertation is to develop a constructivist account of the normative structure of political or civil obligations. The first part of the dissertation focuses on Kant's moral and political constructivism respectively. In chapter two I argue that Kant's account of the normativity of moral obligations is rooted in the idea of moral community which is an objective end that is built into the structure of our practical reasoning. Moral obligations are justified for Kant because they reflect our (...) rational agency and, in particular, the interest we have in promoting a moral community. ;In chapter three I focus on what Kant's idea of the problem of politics: the construction of a society that can successfully and universally administer justice while promoting the interest each citizen has in living in realizing their full capacities as autonomous human beings. I argue that Kant is unable to show that civil obligation---the duties we have qua citizens---are normative in the right sort of way. Kant's account of civil or juridical obligations fails to show that these obligations are normative as moral laws---that they are justified and reason-giving in virtue of their connection to our political consciousness. ;In chapters four through six I present a fully developed account of how political constructivism uses the features of practical reason to evaluate and assemble our ordinary political consciousness---fundamental ideas of free and open society---into a conception of justice, and the normativity of civil obligations---how they are justified and in what sense they are reason-giving for persons qua citizens. ;I lay out Rawls's argument that justice as fairness is a freestanding view by working out exactly how the view is put together without appeal to any particular comprehensive doctrine. After setting out the mechanics, if you will, of political constructivism, I then present an account of the normativity of the political conception: the justification of principles of justice and the prescriptivity or reason-giving force of principles of justice. (shrink)

I describe how close attention to the process of sculpting clay from the perspective of Material Engagement Theory can create a detailed description of a mutable sense of agency and of self. First, I show that sculpting is associated with a loss of sense of agency and self. Second, that to sense agency as a systemic phenomenon creates anxiety. Third, that meaning in an art encounter develops in association with an anterospective viewpoint. Fourth, that within the (...) class='Hi'>logic of the extended mind, emergent meaning becomes openly available for further exploration. Fifth, that artistic creativity is not an opaque process. It proceeds in a similar manner to other forms of human, sense-making activities. Finally, that playing seriously with clay can be used in an investigative manner—as a tool for material conceptualisation. (shrink)

In this paper I propose and motivate a logic of the interdefined concepts of making true and control, understood as intensional propositional operators to be indexed to an agent. While bearing a resemblance to earlier logics in the tradition, the motivations, semantics, and object language theory differ on crucial points. Applying this logic to widespread formal theories of agency, I use it as a framework to argue against the ubiquitous assumption that the strongest actions or options available (...) to a given agent must always be pairwise incompatible. The conclusion is that this assumption conflicts with failures of higher order control of agents over their degree or precision of control, failures exhibited by such imperfect agents as ourselves. I discuss models in this setting for understanding such imperfectly self-controlling agents. In an appendix, I prove several relevant results about the logic described, including soundness and completeness both for it and for certain natural extensions. (shrink)

An agent-centered, goal-directed, resource-bound logic of human reasoning would do well to note that individual cognitive agency is typified by the comparative scantness of available cognitive resources—information, time, and computational capacity, to name just three. This motivates individual agents to set their cognitive agendas proportionately, that is, in ways that carry some prospect of success with the resources on which they are able to draw. It also puts a premium on cognitive strategies which make economical use of those (...) resources. These latter I callscant-resource adjustment strategies,and they supply the context for an analysis of abduction. The analysis is Peircian in tone, especially in the emphasis it places on abduction’signorance-preservingcharacter. My principal purpose here is to tie abduction’s scarce-resource adjustment capacity to its ignorance preservation. (shrink)