This article proposes the use of temporal logic for an analysis of instrumentality inspired by the work of G.H. von Wright. The first part of the article contains the philosophical foundations. We discuss von Wright’s general theory of agency and his account of instrumentality. Moreover, we propose several refinements to this framework via rigorous definitions of the core notions involved. In the second part, we develop a logical system called Temporal Logic of Action and Expectations (TLAE). The logic is inspired (...) by a fragment of propositional dynamic logic based on indeterministic time. The system is proven to be weakly complete relative to its given semantics. We then employ TLAE to formalise and analyse the instrumentality relations defined in the first part of the paper. Last, we point out philosophical implications and possible extensions of our work. (shrink)

STIT logic is a prominent framework for the analysis of multi-agent choice-making. In the available deontic extensions of STIT, the principle of Ought-implies-Can (OiC) fulfills a central role. However, in the philosophical literature a variety of alternative OiC interpretations have been proposed and discussed. This paper provides a modular framework for deontic STIT that accounts for a multitude of OiC readings. In particular, we discuss, compare, and formalize ten such readings. We provide sound and complete sequent-style calculi for all of (...) the various STIT logics accommodating these OiC principles. We formally analyze the resulting logics and discuss how the different OiC principles are logically related. In particular, we propose an endorsement principle describing which OiC readings logically commit one to other OiC readings. (shrink)

This work provides proof-search algorithms and automated counter-model extraction for a class of STIT logics. With this, we answer an open problem concerning syntactic decision procedures and cut-free calculi for STIT logics. A new class of cut-free complete labelled sequent calculi G3LdmL^m_n, for multi-agent STIT with at most n-many choices, is introduced. We refine the calculi G3LdmL^m_n through the use of propagation rules and demonstrate the admissibility of their structural rules, resulting in auxiliary calculi Ldm^m_nL. In the single-agent case, we (...) show that the refined calculi Ldm^m_nL derive theorems within a restricted class of (forestlike) sequents, allowing us to provide proof-search algorithms that decide single-agent STIT logics. We prove that the proof-search algorithms are correct and terminate. (shrink)

This paper examines the conceptual and terminological overlap between theories and models of practical deliberation developed within the fields of Practical Reasoning (PR) and Practical Argumentation (PA). It carefully delineates the volitional, epistemic, normative, and social commitments invoked and explicates various rationales for attributing the label ‘practical’ to instances of reasoning and argumentation. Based on these analyses, the paper develops a new approach to practical deliberation called the Stakeholder Commitment Approach (SCA). By distinguishing between ‘problem holder’ and ‘problem solver’, and (...) specifying the distributions of attributable commitments among the stakeholders, the SCA introduces an extension and refinement of the grounds for assigning the label ‘practical’ that brings PR and PA closer together. (shrink)

Centered around the analysis of the prescriptive portion of the Vedas, the Sanskrit philosophical school of Mīmāṃsā provides a treasure trove of normative investigations. We focus on the leading Mīmāṃsā authors Prabhākara, Kumārila and Maṇḍana, and discuss three modal logics that formalize their deontic theories. In the first part of this paper, we use logic to analyze, compare and clarify the various solutions to the _śyena_ controversy, a two-thousand-year-old problem arising from seemingly conflicting commands in the Vedas. In the second (...) part, the formalized Mīmāṃsā theories are analyzed and employed to provide alternative perspectives on well-known paradoxes from the contemporary field of deontic logic. Thus, we go from logic to Mīmāṃsā and back again. (shrink)

In this work we answer a long standing request for temporal embeddings of deontic STIT logics by introducing the multi-agent STIT logic TDS . The logic is based upon atemporal utilitarian STIT logic. Yet, the logic presented here will be neutral: instead of committing ourselves to utilitarian theories, we prove the logic TDS sound and complete with respect to relational frames not employing any utilitarian function. We demonstrate how these neutral frames can be transformed into utilitarian temporal frames, while preserving (...) validity. Last, we discuss problems that arise from employing binary utility functions in a temporal setting. (shrink)

We present cut-free labelled sequent calculi for a central formalism in logics of agency: STIT logics with temporal operators. These include sequent systems for Ldm , Tstit and Xstit. All calculi presented possess essential structural properties such as contraction- and cut-admissibility. The labelled calculi G3Ldm and G3Tstit are shown sound and complete relative to irreflexive temporal frames. Additionally, we extend current results by showing that also Xstit can be characterized through relational frames, omitting the use of BT+AC frames.

We formally introduce a novel, yet ubiquitous, category of norms: norms of instrumentality. Norms of this category describe which actions are obligatory, or prohibited, as instruments for certain purposes. We propose the Logic of Agency and Norms (LAN) that enables reasoning about actions, instrumentality, and normative principles in a multi-agent setting. Leveraging LAN , we formalize norms of instrumentality and compare them to two prevalent norm categories: norms to be and norms to do. Last, we pose principles relating the three (...) categories and evaluate their validity vis-à-vis notions of deliberative acting. On a technical note, the logic will be shown decidable via the finite model property. (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)

Long ago, when Alexander the Great asked the mathematician Menaechmus for a crash course in geometry, he got the famous reply ``There is no royal road to mathematics.'' Where there was no shortcut for Alexander, there is no shortcut for us. Still, the fact that we have access to computers and mature programming languages means that there are avenues for us that were denied to the kings and emperors of yore. The purpose of this book is to teach logic and (...) mathematical reasoning in practice, and to connect logical reasoning with computer programming in Haskell. Haskell emerged in the 1990s as a standard for lazy functional programming, a programming style where arguments are evaluated only when the value is actually needed. Haskell is a marvelous demonstration tool for logic and maths because its functional character allows implementations to remain very close to the concepts that get implemented, while the laziness permits smooth handling of infinite data structures. This book does not assume the reader to have previous experience with either programming or construction of formal proofs, but acquaintance with mathematical notation, at the level of secondary school mathematics is presumed. Everything one needs to know about mathematical reasoning or programming is explained as we go along. After proper digestion of the material in this book, the reader will be able to write interesting programs, reason about their correctness, and document them in a clear fashion. The reader will also have learned how to set up mathematical proofs in a structured way, and how to read and digest mathematical proofs written by others. This is the updated, expanded, and corrected second edition of a much-acclaimed textbook. Praise for the first edition: 'Doets and van Eijck's ``The Haskell Road to Logic, Maths and Programming'' is an astonishingly extensive and accessible textbook on logic, maths, and Haskell.' Ralf Laemmel, Professor of Computer Science, University of Koblenz-Landau. (shrink)

A substantial amount of recent work in natural language generation has focused on the generation of ‘‘one‐shot’’ referring expressions whose only aim is to identify a target referent. Dale and Reiter's Incremental Algorithm (IA) is often thought to be the best algorithm for maximizing the similarity to referring expressions produced by people. We test this hypothesis by eliciting referring expressions from human subjects and computing the similarity between the expressions elicited and the ones generated by algorithms. It turns out that (...) the success of the IA depends substantially on the ‘‘preference order’’ (PO) employed by the IA, particularly in complex domains. While some POs cause the IA to produce referring expressions that are very similar to expressions produced by human subjects, others cause the IA to perform worse than its main competitors; moreover, it turns out to be difficult to predict the success of a PO on the basis of existing psycholinguistic findings or frequencies in corpora. We also examine the computational complexity of the algorithms in question and argue that there are no compelling reasons for preferring the IA over some of its main competitors on these grounds. We conclude that future research on the generation of referring expressions should explore alternatives to the IA, focusing on algorithms, inspired by the Greedy Algorithm, which do not work with a fixed PO. (shrink)

When producing a description of a target referent in a visual context, speakers need to choose a set of properties that distinguish it from its distractors. Computational models of language production/generation usually model this as a search process and predict that the time taken will increase both with the number of distractors in a scene and with the number of properties required to distinguish the target. These predictions are reminiscent of classic findings in visual search; however, unlike models of reference (...) production, visual search models also predict that search can become very efficient under certain conditions, something that reference production models do not consider. This paper investigates the predictions of these models empirically. In two experiments, we show that the time taken to plan a referring expression—as reflected by speech onset latencies—is influenced by distractor set size and by the number of properties required, but this crucially depends on the discriminability of the properties under consideration. We discuss the implications for current models of reference production and recent work on the role of salience in visual search. (shrink)

This response discusses the experiment reported in Krahmer et al.’s Letter to the Editor of Cognitive Science. We observe that their results do not tell us whether the Incremental Algorithm is better or worse than its competitors, and we speculate about implications for reference in complex domains, and for learning from ‘‘normal” (i.e., non-semantically-balanced) corpora.

Het denken van de Nederlandse filosoof Leo Polak (1880-1941) heeft nog altijd niet aan actualiteit ingeboet. Hij bepleitte hartstochtelijk de autonomie van de menselijke rede, worstelde met de grondslag van onze ethiek en wierp zich in een tijd van politieke massabewegingen en toenemende verzuiling op als kampioen van het vrije denken. Zelfs tijdens de Duitse bezetting hield hij vast aan zijn zelfstandig oordeel – een houding die hij eind 1941 met de dood in een concentratiekamp moest bekopen. Al die jaren (...) hield hij een dagboek bij, voor hem een essentieel middel om greep te krijgen op zijn leven. Op basis hiervan worden in deze bundel nieuwe aspecten van Polaks leven en werk belicht: zijn denken over schuld en vergelding, zijn verhouding tot grote filosofen als Spinoza en Heymans en zijn houding tegenover het nationaalsocialisme, maar ook zijn familieleven, zijn boekenverzameling en zijn geestelijke nalatenschap. (shrink)

Historians of science and the philosophy of science find the substance and stance of Isaac Beeckman's thought highly interesting, for it represented an early attempt to develop a comprehensive picture of the world by means of mechanistic theory, that is, forces acting upon one another. Besides possibly influencing Descartes, this view broke away from medieval religious assumptions and belief in occult forces. Berkel teases out Beeckman's evolving approach to nature by means of his extensive journals, explaining the leading concept (...) of "picturability." Beeckman supplied a stepping stone (one still not widely appreciated) on the path that led to the scientific revolution. (shrink)

This article explores the role of surface ambiguities in referring expressions, and how the risk of such ambiguities should be taken into account by an algorithm that generates referring expressions, if these expressions are to be optimally effective for a hearer. We focus on the ambiguities that arise when adjectives occur in coordinated structures. The central idea is to use statistical information about lexical co‐occurrence to estimate which interpretation of a phrase is most likely for human readers, and to avoid (...) generating phrases where misunderstandings are likely. Various aspects of the problem were explored in three experiments in which responses by human participants provided evidence about which reading was most likely for certain phrases, which phrases were deemed most suitable for particular referents, and the speed at which various phrases were read. We found a preference for ‘‘clear’’ expressions to ‘‘unclear’’ ones, but if several of the expressions are ‘‘clear,’’ then brief expressions are preferred over non‐brief ones even though the brief ones are syntactically ambiguous and the non‐brief ones are not; the notion of clarity was made precise using Kilgarriff's Word Sketches. We outline an implemented algorithm that generates noun phrases conforming to our hypotheses. (shrink)

From 22-25 May, 1999, the University of Groningen hosted an international conference on 'The Book of Nature. Continuity and change in European and American attitudes towards the natural world'. From Antiquity down to our own time, theologians, philosophers and scientists have often compared nature to a book, which might, under the right circumstances, be read and interpreted in order to come closer to the 'Author' of nature, God. The 'reading' of this book was not regarded as mere idle curiosity, but (...) it was seen as leading to a deeper understanding of God's wisdom and power, and it culturally legitimated and promoted a positive attitude towards nature and its study. A selection of the papers which were delivered at the conference has been edited in two volumes. The first deals with the perception of the Book of Nature in Antiquity and the Middle Ages; the second volume is devoted to the history of the concept in early modern and modern history. (shrink)

Prosocial compensation is a corporate social responsibility practice that involves donating money to a charitable cause on behalf of customers as a means to compensate them for their loss after a service failure. In order to determine the effectiveness of PC, we carried out three experiments while also comparing its effectiveness within private and public settings. Experiment 1 focused on the signaling effects of communicating the promise to offer PC to potential customers in the event of service failure. Results show (...) that, in both private and public settings, PC has positive effects on corporate image, credibility, and word-of-mouth intent. More significantly, PC improved one’s CSR image, whereas more tangible compensation, such as a gift voucher, did not. Experiments 2A and 2B focused on the effects of offering PC after a service failure on perceptions of justice. Results show that PC contributes to perceived distributive justice, procedural justice, and post-recovery satisfaction in both private and public settings. Our study showed that PC could be a relevant new CSR practice for organizations wanting to enhance theirs CSR image while contributing to fulfilling their ethical and philanthropic CSR responsibilities. We discuss the implications of our findings and offer several avenues for follow-up research on this initial study on PC. (shrink)

Ibn al-Sāʿī, Consorts of the Caliphs: Women and the Court of Baghdad. Edited by Shawkat M. Toorawa, translated by Editors of LAL. Library of Arabic Literature. New York: New York University Press, 2015. Pp. xlv + 226. $30.

This paper asks why information should ever be expressed vaguely, re-assessing some previously proposed answers to this question and suggesting some new ones. Particular attention is paid to the benefits that vague expressions can have in situations where agreement over the meaning of an expression cannot be taken for granted. A distinction between two different versions of the above-mentioned question is advocated. The first asks why human languages contain vague expressions, the second question asks when and why a speaker should (...) choose a vague expression when communicating with a hearer. While the former question is purely theoretical, the latter has practical implications for the computational generation of utterances in Natural Language Generation (NLG). (shrink)

Media in Question sets the agenda for a revitalized debate on the hybrid communicative practices that constitute the postmodern media landscape: practices that cross the boundaries between fact and fiction, information and entertainment, public knowledge, and popular culture. In this challenging and provocative collection, the individual contributors rethink key issuesùthe meaning of the public interest, the quality of media performance, and deregulation. In the process they raise questions rarely addressed in normative media theories, for example, the ethics of sports reporting, (...) the moral reasoning in popular culture, and the required professional standards for infotainment genres such as reality television and gossip journalism. Accessible and wide-ranging, The Media in Question will be essential reading for students in mass communication and political communication studies. (shrink)

The Danish theologian-philosopher K. E. Løgstrup is second in reputation in his homeland only to Søren Kierkegaard. He is best known outside Europe for his _The Ethical Demand_, first published in Danish in 1956 and published in an expanded English translation in 1997. _Beyond the Ethical Demand_ contains excerpts, translated into English for the first time, from the numerous books and essays Løgstrup continued to write throughout his life. In the first essay, he engages the critical response to _The Ethical (...) Demand,_ clarifying, elaborating, or defending his original positions. In the next three essays, he extends his contention that human ethics “demands” that we are concerned for the other by introducing the crucial concept of “sovereign expressions of life.” Like Levinas, Løgstrup saw in the phenomenon of “the other” the ground for his ethics. In his later works he developed this concept of “the sovereign expressions of life,” spontaneous phenomena such as trust, mercy, and sincerity that are inherently other-regarding. The last two essays connect his ethics with political life. Interest in Løgstrup in the English-speaking academic community continues to grow, and these important original sources will be essential tools for scholars exploring the further implications of his ethics and phenomenology. “K. E. Løgstrup’s work undoubtedly made in his time an original contribution to the field of moral philosophy and philosophy of religion. This translation makes extracts from his later publications on moral philosophy accessible to an English-speaking audience. I am again impressed by the depth of his ideas, which are certainly not outdated and still relevant for contemporary debates in moral philosophy.” —_Bert Musschenga, Vrije Universiteit, Amsterdam _ “Making a large part of Knud Løgstrup’s legacy accessible to the English-speaking public is an event of enormous cultural, philosophical and political importance—and we are all in debt to his disciple, Kies van Kooten Niekerk, and the University Press of Notre Dame, for making it happen. Løgstrup, alongside few other giants of 20th Century ethical thought, like Emmanuel Levinas or Hans Jonas, anticipated and articulated all the major challenges and urgent tasks with which the coming century is likely to confront the moral self. Our ethical discourse was all the poorer so far for being barred access to his findings and proposition. This will no longer be the case.” —_Zygmunt Bauman, emeritus, University of Leeds_ “The publication of an English translation of Knut Eljert Løgstrup's later works in ethics provides a wider readership with the opportunity to better understand his important contribution to ethics in the second half of the last century. With his notion of the _Sovereign Expressions of Life_ Løgstrup articulates his rejection of moral atomism that has become influential in recent times. The introduction and annotation by Kees van Kooten Niekerk are very helpful to see how Løgstrup's thought developed beyond _The Ethical Demand.” —__Hans S. Reinders, Vrije Universiteit, Amsterdam_. (shrink)

This article introduces the topic ‘‘Production of Referring Expressions: Bridging the Gap between Computational and Empirical Approaches to Reference’’ of the journal Topics in Cognitive Science. We argue that computational and psycholinguistic approaches to reference production can benefit from closer interaction, and that this is likely to result in the construction of algorithms that differ markedly from the ones currently known in the computational literature. We focus particularly on determinism, the feature of existing algorithms that is perhaps most clearly at (...) odds with psycholinguistic results, discussing how future algorithms might include non-determinism, and how new psycholinguistic experiments could inform the development of such algorithms. (shrink)

This article offers a survey of computational research on referring expressions generation (REG). It introduces the REG problem and describes early work in this area, discussing what basic assumptions lie behind it, and showing how its remit has widened in recent years. We discuss computational frameworks underlying REG, and demonstrate a recent trend that seeks to link up REG algorithms with well-established Knowledge Representation traditions. Considerable attention is given to recent efforts at evaluating REG algorithms and the lessons that they (...) allow us to learn. The article concludes with a discussion of the way forward in REG, focussing on references in larger and more realistic settings. (shrink)

A substantial amount of recent work in natural language generation has focused on the generation of ‘‘one-shot’’ referring expressions whose only aim is to identify a target referent. Dale and Reiter's Incremental Algorithm (IA) is often thought to be the best algorithm for maximizing the similarity to referring expressions produced by people. We test this hypothesis by eliciting referring expressions from human subjects and computing the similarity between the expressions elicited and the ones generated by algorithms. It turns out that (...) the success of the IA depends substantially on the ‘‘preference order’’ (PO) employed by the IA, particularly in complex domains. While some POs cause the IA to produce referring expressions that are very similar to expressions produced by human subjects, others cause the IA to perform worse than its main competitors; moreover, it turns out to be difficult to predict the success of a PO on the basis of existing psycholinguistic findings or frequencies in corpora. We also examine the computational complexity of the algorithms in question and argue that there are no compelling reasons for preferring the IA over some of its main competitors on these grounds. We conclude that future research on the generation of referring expressions should explore alternatives to the IA, focusing on algorithms, inspired by the Greedy Algorithm, which do not work with a fixed PO. (shrink)

The Danish philosopher K. E. Løgstrup is best known in the Anglo-American world for his original work in ethics, primarily in _The Ethical Demand _. Løgstrup continued to write extensively on issues in ethics and phenomenology throughout his life, and extracts from some of his later writings are now also available in translation in _Beyond the Ethical Demand_. In _Concern for the Other: The Ethics of K. E. Løgstrup_, eleven scholars examine the structure, intention, and originality of Løgstrup's ethics as (...) a whole. This collection of essays is a companion to _Beyond the Ethical Demand_, as well as to _The Ethical Demand_. The essays examine Løgstrup’s crucial concept of the “sovereign expressions of life”; his view of moral principles as a substitute for, or inferior form of, ethics; his relationships to other philosophers, including the twentieth-century British moral philosophers; and the role of his Lutheran background in his ethics. Løgstrup also firmly advanced the controversial thesis, examined by several essays in this volume, that the demand for “other-concern” central to his ethics does not depend on religious faith. “The significance of Løgstrup’s work is well demonstrated by the substantive criticisms made of that work by the essays here collected. Hopefully this book will encourage others to engage this significant but unfortunately not well-known thinker.” —_Stanley Hauerwas, Gilbert T. Rowe Professor of Theological Ethics, Duke Divinity School_ “Svend Andersen and Kees van Kooten Niekerk have done a great service for everyone with the publication of this stellar book on the thought of Knud E. Løgstrup, the most prominent Danish theologian-philosopher of the last century. CONCERN FOR THE OTHER includes essays by renowned thinkers who critically engage Løgstrup’s work with both insight and depth. The book thereby provides an engagement with this important thinker’s ideas about morality, trust, and responsibility and yet also presents features of the current state of the debate within ethics. I enthusiastically commend this book to anyone interested in contemporary ethics and moral theory as well as the relation between theology and philosophy.” —_William Schweiker, Edward L. Ryerson Distinguished Service Professor of Theological Ethics, The University of Chicago_. (shrink)