Presenting the first comprehensive, in-depth study of hyperintensionality, this book equips readers with the basic tools needed to appreciate some of current and future debates in the philosophy of language, semantics, and metaphysics. After introducing and explaining the major approaches to hyperintensionality found in the literature, the book tackles its systematic connections to normativity and offers some contributions to the current debates. The book offers undergraduate and graduate students an essential introduction to the topic, while also helping professionals in related fields get up to speed on open research-level problems.

This book defines a logical system called the Protocol-theoretic Logic of Epistemic Norms (PLEN), it develops PLEN into a formal framework for representing and reasoning about epistemic norms, and it shows that PLEN is theoretically interesting and useful with regard to the aims of such a framework. In order to motivate the project, the author defends an account of epistemic norms called epistemic proceduralism. The core of this view is the idea that, in virtue of their indispensable, regulative role in cognitive life, epistemic norms are closely intertwined with procedural rules that restrict epistemic actions, procedures, and processes. The resulting organizing principle of the book is that epistemic norms are protocols for epistemic planning and control. The core of the book is developing PLEN, which is essentially a novel variant of propositional dynamic logic (PDL) distinguished by more or less elaborate revisions of PDL’s syntax and semantics. The syntax encodes the procedural content of epistemic norms by means of the well-known protocol or program constructions of dynamic and epistemic logics. It then provides a novel language of operators on protocols, including a range of unique protocol equivalence relations, syntactic operations on protocols, and various procedural relations among protocols in addition to the standard dynamic (modal) operators of PDL. The semantics of the system then interprets protocol expressions and expressions embedding protocols over a class of directed multigraph-like structures rather than the standard labeled transition systems or modal frames. The intent of the system is to better represent epistemic dynamics, build a logic of protocols atop it, and then show that the resulting logic of protocols is useful as a logical framework for epistemic norms. The resulting theory of epistemic norms centers on notions of norm equivalence derived from theories of process equivalence familiar from the study of dynamic and modal logics. The canonical account of protocol equivalence in PLEN turns out to possess a number of interesting formal features, including satisfaction of important conditions on hyperintensional equivalence, a matter of recently recognized importance in the logic of norms, generally. To show that the system is interesting and useful as a framework for representing and reasoning about epistemic norms, the author applies the logical system to the analysis of epistemic deontic operators, and, partly on the basis of this, establishes representation theorems linking protocols to the action-guiding content of epistemic norms. The protocol-theoretic logic of epistemic norms is then shown to almost immediately validate the main principles of epistemic proceduralism.

Edited in collaboration with FoLLI, the Association of Logic, Language and Information this book constitutes the refereed proceedings of the of the 29th International Workshop on Logic, Language, Information, and Computation, WoLLIC 2023, held in Halifax, NS, Canada, during July 11–14, 2023. The 24 full papers (21 contributed, 3 invited) included in this book were carefully reviewed and selected from 46 submissions. The book also contains the abstracts for the 7 invited talks and 4 tutorials presented at WoLLIC 2023. The WoLLIC conference series aims at fostering interdisciplinary research in pure and applied logic.

Edited in collaboration with FoLLI, the Association of Logic, Language and Information this book constitutes the refereed proceedings of the 27th Workshop on Logic, Language, Information and Communication, WoLLIC 2021, Virtual Event, in October 2021. The 25 full papers presented included 6 invited lectures were fully reviewed and selected from 50 submissions. The idea is to have a forum which is large enough in the number of possible interactions between logic and the sciences related to information and computation.

This book intends to unite studies in different fields related to the development of the relations between logic, law and legal reasoning. Combining historical and philosophical studies on legal reasoning in Civil and Common Law, and on the often neglected Arabic and Talmudic traditions of jurisprudence, this project unites these areas with recent technical developments in computer science. This combination has resulted in renewed interest in deontic logic and logic of norms that stems from the interaction between artificial intelligence and law and their applications to these areas of logic. The book also aims to motivate and launch a more intense interaction between the historical and philosophical work of Arabic, Talmudic and European jurisprudence. The publication discusses new insights in the interaction between logic and law, and more precisely the study of different answers to the question: what role does logic play in legal reasoning? Varying perspectives include that of foundational studies (such as logical principles and frameworks) to applications, and historical perspectives.

"Moral realism" is a family of theories of morality united by the idea that there are moral facts--facts about what is right or wrong or good or bad--and that morality is not simply a matter of personal preferences, emotions, attitudes, or sociological conventions. The fundamental thought underlying moral realism can be expressed as a parity thesis. There are many kinds of facts, including physical, psychological, mathematical, temporal, and moral facts. So understood, moral realism can be distinguished from a variety of anti-realist theories including expressivism, non-cognitivism, and error theory. The Handbook is divided into four parts, the first of which contains essays about the basic concepts and distinctions which characterize moral realism. The subsequent parts contain essays first defending the idea that morality is a naturalistic phenomenon like other subject matters studied by the empirical sciences; second, that morality is a non-natural phenomenon like logic or "pure rationality"; and the final section is dedicated to those theories which deny the usefulness of the natural/non-natural distinction. The twenty-five commissioned essays cover the field of moral realism in a comprehensive and highly accessible way.

Mark Jago presents an original philosophical account of meaningful thought: in particular, how it is meaningful to think about things that are impossible. We think about impossible things all the time. We can think about alchemists trying to turn base metal to gold, and about unfortunate mathematicians trying to square the circle. We may ponder whether god exists; and philosophers frequently debate whether properties, numbers, sets, moral and aesthetic qualities, and qualia exist. In many philosophical or mathematical debates, when one side of the argument gets things wrong, it necessarily gets them wrong. As we consider both sides of one of these philosophical arguments, we will at some point think about something that's impossible. Yet most philosophical accounts of meaning and content hold that we can't meaningfully think or reason about the impossible. In The Impossible, Jago argues that we often gain new information, new beliefs and, sometimes, fresh knowledge through logic, mathematics and philosophy. That is why logic, mathematics, and philosophy are useful. We therefore require accounts of knowledge and belief, of information and content, and of meaning which allow space for the impossible. Jago's aim in this book is to provide such accounts. He gives a detailed analysis of the concept of hyperintensionality, whereby logically equivalent contents may be distinct, and develops a theory in terms of possible and impossible worlds. Along the way, he provides a theory of what those worlds are and how they feature in our analysis of normative epistemic concepts: knowledge, belief, information, and content.

This is a collection of essays on Wittgenstein and Wittgensteinian themes that appeared between 1996 and 2019. It is divided into three parts, with a common trajectory laid out in a substantial introduction. The first part links meaning, necessity and normativity. It defends and modifies Wittgenstein’s claim that the idea of a ‘grammatical rule’ holds the key to understanding linguistic meaning and its connection to necessary truth. The second part elucidates the connections between meaning, concepts and thought in Wittgenstein and beyond. It shows how he laid the grounds for a sound understanding of four contested issues—radical interpretation, concepts, nonsense and animal minds. The third part provides a qualified defence of Wittgenstein’s controversial idea that philosophical problems are conceptual, and thereby rooted in confusions concerning the meanings of and semantic relations between linguistic expressions. Against irrationalist interpretations, it demonstrates that Wittgenstein’s method is argumentative rather than therapeutic. The collection as a whole makes a powerful case for an analytic perspective on Wittgenstein. The essays bring out the abiding relevance of Wittgenstein’s reflections to contemporary debates on central topics such as the role of normativity, the foundations of linguistic meaning, the nature of concepts, the possibility of animal thought, and the proper methods of philosophy.

Oxford Studies in Metaethics is the only publication devoted exclusively to original philosophical work in the foundations of ethics. It provides an annual selection of much of the best new scholarship being done in the field. Its broad purview includes work being done at the intersections of ethical theory with metaphysics, epistemology, philosophy of language, and philosophy of mind. The essays included in the series provide an excellent basis for understanding recent developments in the field; those who would like to acquaint themselves with the current state of play in metaethics would do well to start here.

This LNCS book is part of the FOLLI book series and constitutes the proceedings of the 9th International Workshop on Logic, Rationality, and Interaction, LORI 2023, held in Jinan, China, in October 2023. The 15 full papers presented together with 7 short papers in this book were carefully reviewed and selected from 40 submissions. The workshop covers a wide range on the following topics such as agency; argumentation and agreement; belief representation; probability and uncertainty; belief revision and belief merging; knowledge and action; dynamics of informational attitudes; intentions, plans, and goals; decision making and planning; preference and utility; cooperation; strategic reasoning and game theory; epistemology; social choice; social interaction; speech acts; knowledge representation; norms and normative systems; natural language; rationality; philosophical logic.