By classic results in social choice theory, any reasonable preferential voting method sometimes gives individuals an incentive to report an insincere preference. The extent to which different voting methods are more or less resistant to such strategic manipulation has become a key consideration for comparing voting methods. Here we measure resistance to manipulation by whether neural networks of varying sizes can learn to profitably manipulate a given voting method in expectation, given different types of limited information about how other voters (...) will vote. We trained over 70,000 neural networks of 26 sizes to manipulate against 8 different voting methods, under 6 types of limited information, in committee-sized elections with 5-21 voters and 3-6 candidates. We find that some voting methods, such as Borda, are highly manipulable by networks with limited information, while others, such as Instant Runoff, are not, despite being quite profitably manipulated by an ideal manipulator with full information. For the two probability models for elections that we use, the overall least manipulable of the 8 methods we study are Condorcet methods, namely Minimax and Split Cycle. (shrink)

This chapter provides a brief introduction to propositional epistemic logic and its applications to epistemology. No previous exposure to epistemic logic is assumed. Epistemic-logical topics discussed include the language and semantics of basic epistemic logic, multi-agent epistemic logic, combined epistemic-doxastic logic, and a glimpse of dynamic epistemic logic. Epistemological topics discussed include Moore-paradoxical phenomena, the surprise exam paradox, logical omniscience and epistemic closure, formalized theories of knowledge, debates about higher-order knowledge, and issues of knowability raised by Fitch’s paradox. The references (...) and recommended readings provide gateways for further exploration. (shrink)

Inquisitive logic is a research program seeking to expand the purview of logic beyond declarative sentences to include the logic of questions. To this end, inquisitive propositional logic extends classical propositional logic for declarative sentences with principles governing a new binary connective of inquisitive disjunction, which allows the formation of questions. Recently inquisitive logicians have considered what happens if the logic of declarative sentences is assumed to be intuitionistic rather than classical. In short, what should inquisitive logic be on an (...) intuitionistic base? In this paper, we provide an answer to this question from the perspective of nuclear semantics, an approach to classical and intuitionistic semantics pursued in our previous work. In particular, we show how Beth semantics for intuitionistic logic naturally extends to a semantics for inquisitive intuitionistic logic. In addition, we show how an explicit view of inquisitive intuitionistic logic comes via a translation into propositional lax logic, whose completeness we prove with respect to Beth semantics. (shrink)

There is an extensive literature in social choice theory studying the consequences of weakening the assumptions of Arrow's Impossibility Theorem. Much of this literature suggests that there is no escape from Arrow-style impossibility theorems unless one drastically violates the Independence of Irrelevant Alternatives (IIA). In this paper, we present a more positive outlook. We propose a model of comparing candidates in elections, which we call the Advantage-Standard (AS) model. The requirement that a collective choice rule (CCR) be rationalizable by the (...) AS model is in the spirit of but weaker than IIA; yet it is stronger than what is known in the literature as weak IIA (two profiles alike on x, y cannot have opposite strict social preferences on x and y). In addition to motivating violations of IIA, the AS model makes intelligible violations of another Arrovian assumption: the negative transitivity of the strict social preference relation P. While previous literature shows that only weakening IIA to weak IIA or only weakening negative transitivity of P to acyclicity still leads to impossibility theorems, we show that jointly weakening IIA to AS rationalizability and weakening negative transitivity of P leads to no such impossibility theorems. Indeed, we show that several appealing CCRs are AS rationalizable, including even transitive CCRs. (shrink)

In this paper, we study three representations of lattices by means of a set with a binary relation of compatibility in the tradition of Ploščica. The standard representations of complete ortholattices and complete perfect Heyting algebras drop out as special cases of the first representation, while the second covers arbitrary complete lattices, as well as complete lattices equipped with a negation we call a protocomplementation. The third topological representation is a variant of that of Craig, Haviar, and Priestley. We then (...) extend each of the three representations to lattices with a multiplicative unary modality; the representing structures, like so-called graph-based frames, add a second relation of accessibility interacting with compatibility. The three representations generalize possibility semantics for classical modal logics to non-classical modal logics, motivated by a recent application of modal orthologic to natural language semantics. (shrink)

In "A Problem in Possible-World Semantics," David Kaplan presented a consistent and intelligible modal principle that cannot be validated by any possible world frame (in the terminology of modal logic, any neighborhood frame). However, Kaplan's problem is tempered by the fact that his principle is stated in a language with propositional quantification, so possible world semantics for the basic modal language without propositional quantifiers is not directly affected, and the fact that on careful inspection his principle does not target the (...) world part of possible world semantics—the atomicity of the algebra of propositions—but rather the idea of propositional quantification over a complete Boolean algebra of propositions. By contrast, in this paper we present a simple and intelligible modal principle, without propositional quantifiers, that cannot be validated by any possible world frame precisely because of their assumption of atomicity (i.e., the principle also cannot be validated by any atomic Boolean algebra expansion). It follows from a theorem of David Lewis that our logic is as simple as possible in terms of modal nesting depth (two). We prove the consistency of the logic using a generalization of possible world semantics known as possibility semantics. We also prove the completeness of the logic (and two other relevant logics) with respect to possibility semantics. Finally, we observe that the logic we identify naturally arises in the study of Peano Arithmetic. (shrink)

Brouwer's views on the foundations of mathematics have inspired the study of intuitionistic logic, including the study of the intuitionistic propositional calculus and its extensions. The theory of these systems has become an independent branch of logic with connections to lattice theory, topology, modal logic and other areas. This paper aims to present a modern account of semantics for intuitionistic propositional systems. The guiding idea is that of a hierarchy of semantics, organized by increasing generality: from the least general Kripke (...) semantics on through Beth semantics, topological semantics, Dragalin semantics, and finally to the most general algebraic semantics. While the Kripke, topological, and algebraic semantics have been extensively studied, the Beth and Dragalin semantics have received less attention. We bring Beth and Dragalin semantics to the fore, relating them to the concept of a nucleus from pointfree topology, which provides a unifying perspective on the semantic hierarchy. (shrink)

What are the conditions under which one biological object is a part of another biological object? This paper answers this question by developing a general, systematic account of biological parthood. I specify two criteria for biological parthood. Substantial Spatial Inclusionrequires biological parts to be spatially located inside or in the region that the natural boundary of t he biological whole occupies. Compositional Relevance captures the fact that a biological part engages in a biological process that must make a necessary contribution (...) to a condition that is minimally sufficient to one or more of the characteristic behaviors of the biological whole. Instead of emphasizing the diversity of part-whole relations in the biological world, this paper asks what biological part-whole relations have in common and what constrains their existence, in general. After presenting the two criteria for biological parthood I discuss in how far my account can cope with hard cases (e.g., redundant parts) and I reveal the merits and limits of monism. (shrink)

This paper studies connections between two alternatives to the standard probability calculus for representing and reasoning about uncertainty: imprecise probability andcomparative probability. The goal is to identify complete logics for reasoning about uncertainty in a comparative probabilistic language whose semantics is given in terms of imprecise probability. Comparative probability operators are interpreted as quantifying over a set of probability measures. Modal and dynamic operators are added for reasoning about epistemic possibility and updating sets of probability measures.

The standard topological representation of a Boolean algebra via the clopen sets of a Stone space requires a nonconstructive choice principle, equivalent to the Boolean Prime Ideal Theorem. In this article, we describe a choice-free topological representation of Boolean algebras. This representation uses a subclass of the spectral spaces that Stone used in his representation of distributive lattices via compact open sets. It also takes advantage of Tarski’s observation that the regular open sets of any topological space form a Boolean (...) algebra. We prove without choice principles that any Boolean algebra arises from a special spectral space X via the compact regular open sets of X; these sets may also be described as those that are both compact open in X and regular open in the upset topology of the specialization order of X, allowing one to apply to an arbitrary Boolean algebra simple reasoning about regular opens of a separative poset. Our representation is therefore a mix of Stone and Tarski, with the two connected by Vietoris: the relevant spectral spaces also arise as the hyperspace of nonempty closed sets of a Stone space endowed with the upper Vietoris topology. This connection makes clear the relation between our point-set topological approach to choice-free Stone duality, which may be called the hyperspace approach, and a point-free approach to choice-free Stone duality using Stone locales. Unlike Stone’s representation of Boolean algebras via Stone spaces, our choice-free topological representation of Boolean algebras does not show that every Boolean algebra can be represented as a field of sets; but like Stone’s representation, it provides the benefit of a topological perspective on Boolean algebras, only now without choice. In addition to representation, we establish a choice-free dual equivalence between the category of Boolean algebras with Boolean homomorphisms and a subcategory of the category of spectral spaces with spectral maps. We show how this duality can be used to prove some basic facts about Boolean algebras. (shrink)

Reasoning about what other people know is an important cognitive ability, known as epistemic reasoning, which has fascinated psychologists, economists, and logicians. In this paper, we propose a computational model of humans’ epistemic reasoning, including higher-order epistemic reasoning—reasoning about what one person knows about another person’s knowledge—that we test in an experiment using a deductive card game called “Aces and Eights”. Our starting point is the model of perfect higher-order epistemic reasoners given by the framework of dynamic epistemic logic. We (...) modify this idealized model with bounds on the level of feasible epistemic reasoning and stochastic update of a player’s space of possibilities in response to new information. These modifications are crucial for explaining the variation in human performance across different participants and different games in the experiment. Our results demonstrate how research on epistemic logic and cognitive models can inform each other. (shrink)

How is hope to be found amid the ethical and political dilemmas of modern life? Writer and philosopher Mary Zournazi brought her questions to some of the most thoughtful intellectuals at work today. She discusses "joyful revolt" with Julia Kristeva, the idea of "the rest of the world" with Gayatri Spivak, the "art of living" with Michel Serres, the "carnival of the senses" with Michael Taussig, the relation of hope to passion and to politics with Chantal Mouffe and Ernesto (...) Laclau. A dozen stimulating minds weigh in with their visions of a better social and political order. The result is a collaboration - of writing, of thinking, and of politics - that demonstrates more clearly than any single-authored project could how ideas encountering one another can produce the vision needed for social change. (shrink)

There is a prevailing conviction that if traditional medicine (TRM) or complementary and alternative medicine (CAM) are integrated into healthcare systems, modern scientific medicine (MSM) should retain its principal status. This paper contends that this position is misguided in medical contexts where TRM is established and remains vibrant. By reflecting on the Chinese policy on three entrenched forms of TRM (Tibetan, Mongolian and Uighur medicines) in western regions of China, the paper challenges the ideology of science that lies behind the (...) demand that all traditional forms of medicine be evaluated and reformed according to MSM standards. Tibetan medicine is used as a case study to indicate the falsity of a major premise of the scientific ideology. The conclusion is that the proper integrative system for TRM and MSM is a dual standard based system in which both TRM and MSM are free to operate according to their own medical standards. (shrink)

Mary Shepherd's An Essay upon the Relation of Cause and Effect, first published in 1824, was a pioneering work in metaphysics and epistemology. Together with her 1827 Essays on the Perception of an External Universe, they make her one of the most important philosophers of her era. Although widely neglected by the history of philosophy in the decades after her death, her works have recently begun to attract the attention and sustained study they deserve. In the course of her (...) writings, Shepherd offers trenchant and detailed rebuttals of the arguments and conclusions of many prominent predecessors-including George Berkeley, Thomas Reid, Dugald Stewart, Thomas Brown, William Lawrence, and especially David Hume-but she is no merely negative thinker. On the contrary, her critiques are always in the service of her own distinctive and highly original doctrines, which are of striking contemporary interest. Appearing two hundred years after its original publication, this is the first full modern edition of her first book, which presents and defends the theory of causation and scientific knowledge that constitutes the cornerstone of her entire philosophy. The edition includes an extensive introduction and scholarly notes throughout that provide historical and philosophical context while explaining the central ideas of the work. It also includes Shepherd's two essays published in 1828 and all of her known letters-all but one of them published here for the first time-which shed significant additional light on her philosophical ideas. (shrink)

This article identifies a prevalent strand of feminist writing on beauty and aesthetic surgery and explores some of the contradictions and inconsistencies inscribed within it. In particular, we concentrate on three central feminist claims: that living in a misogynist culture produces aesthetic surgery as an issue predominantly concerning women; that pain - both physical and psychic - is a central conceptual frame through which aesthetic surgery should be viewed; and that aesthetic surgery is inherently a normalizing technology. Engaging with these (...) ‘myths’, we explore the tensions uncovered through a historical analysis of the practices of aesthetic surgery as well as the challenges to feminist claims offered by post-feminism. In particular we seek to destabilize the connection in feminist writing between beauty and passivity. We argue that through aesthetic references to denigrated black and working-class bodies, young women may mobilize aesthetic surgeries to reinscribe active sexuality on the feminine body. (shrink)

Anger has potential epistemic value in the way that it can facilitate a process of our coming to have knowledge and understanding regarding the issue about which we are angry. The nature of anger, however, may nevertheless be such that it ultimately undermines this very process. Common non-philosophical complaints about anger, for instance, often target the angry person as being somehow irrational, where an unformulated assumption is that her anger undermines her capacity to rationally engage with the issue about which (...) she is angry. Call this assumption the charge of emotional irrationality regarding anger. Such a charge is pernicious when levelled at the anger of those in positions of marginalisation or oppression, where it can threaten to silence voices on the very issue of the injustices that they face. In this paper I thus provide a much-needed interrogation of this charge. Firstly, and drawing on empirical literature on the effects of anger on decision-making, I flesh out the charge and why it poses a threat to how the epistemic value of anger has been defended. Secondly, I argue that the charge of emotional irrationality regarding anger can nevertheless be unwarranted, at least within a common context of political anger. (shrink)

Discussion of Wittgenstein's Tractatus is currently dominated by two opposing interpretations of the work: a metaphysical or realist reading and the 'resolute' reading of Diamond and Conant. Marie McGinn's principal aim in this book is to develop an alternative interpretative line, which rejects the idea, central to the metaphysical reading, that Wittgenstein sets out to ground the logic of our language in features of an independently constituted reality, but which allows that he aims to provide positive philosophical insights into how (...) language functions. McGinn takes as a guiding principle the idea that we should see Wittgenstein's early work as an attempt to eschew philosophical theory and to allow language itself to reveal how it functions. By this account, the aim of the work is to elucidate what language itself makes clear, namely, what is essential to its capacity to express thoughts that are true or false. However, the early Wittgenstein undertakes this descriptive project in the grip of a set of preconceptions concerning the essence of language that determine both how he conceives the problem and the approach he takes to the task of clarification. Nevertheless, the Tractatus contains philosophical insights, achieved despite his early preconceptions, that form the foundation of his later philosophy. -/- The anti-metaphysical interpretation that is presented includes a novel reading of the problematic opening sections of the Tractatus, in which the apparently metaphysical status of Wittgenstein's remarks is shown to be an illusion. The book includes a discussion of the philosophical background to the Tractatus, a comprehensive interpretation of Wittgenstein's early views of logic and language, and an interpretation of the remarks on solipsism. The final chapter is a discussion of the relation between the early and the later philosophy that articulates the fundamental shift in Wittgenstein's approach to the task of understanding how language functions and reveal the still more fundamental continuity in his conception of his philosophical task. (shrink)

Epistemic closure has been a central issue in epistemology over the last forty years. According to versions of the relevant alternatives and subjunctivist theories of knowledge, epistemic closure can fail: an agent who knows some propositions can fail to know a logical consequence of those propositions, even if the agent explicitly believes the consequence (having “competently deduced” it from the known propositions). In this sense, the claim that epistemic closure can fail must be distinguished from the fact that agents do (...) not always believe, let alone know, the consequences of what they know—a fact that raises the “problem of logical omniscience” that has been central in epistemic logic. This paper, part I of II, is a study of epistemic closure from the perspective of epistemic logic. First, I introduce models for epistemic logic, based on Lewis’s models for counterfactuals, that correspond closely to the pictures of the relevant alternatives and subjunctivist theories of knowledge in epistemology. Second, I give an exact characterization of the closure properties of knowledge according to these theories, as formalized. Finally, I consider the relation between closure and higher-order knowledge. The philosophical repercussions of these results and results from part II, which prompt a reassessment of the issue of closure in epistemology, are discussed further in companion papers. As a contribution to modal logic, this paper demonstrates an alternative approach to proving modal completeness theorems, without the standard canonical model construction. By “modal decomposition” I obtain completeness and other results for two non-normal modal logics with respect to new semantics. One of these logics, dubbed the logic of ranked relevant alternatives, appears not to have been previously identified in the modal logic literature. More broadly, the paper presents epistemology as a rich area for logical study. (shrink)

Agonistic Democracy explores how theoretical concepts from agonistic democracy can inform institutional design in order to mediate conflict in multicultural, pluralist societies. Drawing on the work of Foucault, Nietzsche, Schmitt, and Arendt, Marie Paxton outlines the importance of their themes of public contestation, contingency and necessary interdependency for contemporary agonistic thinkers. Paxton delineates three distinct approaches to agonistic democracy: David Owen's perfectionist agonism, Mouffe's adversarial agonism, and William Connolly and James Tully's inclusive agonism. Paxton demonstrates how each is fundamental to (...) enabling citizens to cultivate better virtues for themselves and society (Owen), motivating democratic engagement (Mouffe) and enhancing relations of respect and understanding between conflicting citizens (Connolly and Tully). Situated within the context of a deeply polarised post-Trump America and post-Brexit Britain, this book reveals the need to rethink our approach to conflict mediation through democratic institutions. Pulling together insights from experimental research with deliberative democratic innovations, Paxton explores how agonistic theory might be institutionalised further. Through discussing ways in which agonistic institutions might be developed to render democracy more virtuous, more engaging, and more inclusive, Agonistic Democracy provides a unique resource for students of contemporary political theory. (shrink)

We prove that the generalized cancellation axiom for incomplete comparative probability relations introduced by Rios Insua and Alon and Lehrer is stronger than the standard cancellation axiom for complete comparative probability relations introduced by Scott, relative to their other axioms for comparative probability in both the finite and infinite cases. This result has been suggested but not proved in the previous literature.

Scientific culture in Europe and the refugee generation -- Germany and Weimar Berlin as the City of Science -- Origins of a social perspective: doing physical chemistry in Weimar Berlin -- Chemical dynamics and social dynamics in Berlin and Manchester -- Liberalism and the economic foundations of the "Republic of Science" -- Scientific freedom and the social functions of science -- Political foundations of the philosophies of science of Popper, Kuhn, and Polanyi -- Personal knowledge: argument, audiences, and sociological engagement (...) -- Epilogue: SSK, scientific constructivism, and the paradoxical legacy of Polanyi and the 1930s generation. (shrink)

In this book, Mary Midgely turns a spotlight on the fashionable view that we no longer need or use moral judgements. She shows how the question of whether or not we can make moral judgements must inevitably affect our attitudes to the law and its institutions, but also to events that occur in our daily lives.

In traditional semantics for classical logic and its extensions, such as modal logic, propositions are interpreted as subsets of a set, as in discrete duality, or as clopen sets of a Stone space, as in topological duality. A point in such a set can be viewed as a "possible world," with the key property of a world being primeness—a world makes a disjunction true only if it makes one of the disjuncts true—which classically implies totality—for each proposition, a world either (...) makes the proposition true or makes its negation true. This chapter surveys a more general approach to logical semantics, known as possibility semantics, which replaces possible worlds with possibly partial "possibilities." In classical possibility semantics, propositions are interpreted as regular open sets of a poset, as in set-theoretic forcing, or as compact regular open sets of an upper Vietoris space, as in the recent theory of "choice-free Stone duality." The elements of these sets, viewed as possibilities, may be partial in the sense of making a disjunction true without settling which disjunct is true. We explain how possibilities may be used in semantics for classical logic and modal logics and generalized to semantics for intuitionistic logics. The goals are to overcome or deepen incompleteness results for traditional semantics, to avoid the nonconstructivity of traditional semantics, and to provide richer structures for the interpretation of new languages. (shrink)

This paper responds to John Burgess's ‘Mathematics and _Bleak House_’. While Burgess's rejection of hermeneutic fictionalism is accepted, it is argued that his two main attacks on revolutionary fictionalism fail to meet their target. Firstly, ‘philosophical modesty’ should not prevent philosophers from questioning the truth of claims made within successful practices, provided that the utility of those practices as they stand can be explained. Secondly, Carnapian scepticism concerning the meaningfulness of _metaphysical_ existence claims has no force against a _naturalized_ version (...) of fictionalism, according to which our ordinary standards of scientific evidence may show that we have no reason to believe the mathematical existence claims made within the context of our mathematical and scientific theories. (shrink)

We introduce new algebraic and topological semantics for inquisitive logic. The algebraic semantics is based on special Heyting algebras, which we call inquisitive algebras, with propositional valuations ranging over only the ¬¬-fixpoints of the algebra. We show how inquisitive algebras arise from Boolean algebras: for a given Boolean algebra B, we define its inquisitive extension H(B) and prove that H(B) is the unique inquisitive algebra having B as its algebra of ¬¬-fixpoints. We also show that inquisitive algebras determine Medvedev’s logic (...) of finite problems. In addition to the algebraic characterization of H(B), we give a topological characterization of H(B) in terms of the recently introduced choice-free duality for Boolean algebras using so-called upper Vietoris spaces (UV-spaces). In particular, while a Boolean algebra B is realized as the Boolean algebra of compact regular open elements of a UV-space dual to B, we show that H(B) is realized as the algebra of compact open elements of this space. This connection yields a new topological semantics for inquisitive logic. (shrink)

A well-known open problem in epistemic logic is to give a syntactic characterization of the successful formulas. Semantically, a formula is successful if and only if for any pointed model where it is true, it remains true after deleting all points where the formula was false. The classic example of a formula that is not successful in this sense is the “Moore sentence” p ∧ ¬BOXp, read as “p is true but you do not know p.” Not only is the (...) Moore sentence unsuccessful, it is self-refuting, for it never remains true as described. We show that in logics of knowledge and belief for a single agent (extended by S5), Moorean phenomena are the source of all self-refutation; moreover, in logics for an introspective agent (extending KD45), Moorean phenomena are the source of all unsuccessfulness as well. This is a distinctive feature of such logics, for with a non-introspective agent or multiple agents, non-Moorean unsuccessful formulas appear. We also consider how successful and self-refuting formulas relate to the Cartesian and learnable formulas, which have been discussed in connection with Fitch’s “paradox of knowability.” We show that the Cartesian formulas are exactly the formulas that are not eventually self-refuting and that not all learnable formulas are successful. In an appendix, we give syntactic characterizations of the successful and the self-refuting formulas. (shrink)

Epistemic modals have peculiar logical features that are challenging to account for in a broadly classical framework. For instance, while a sentence of the form ‘p, but it might be that not p’ appears to be a contradiction, 'might not p' does not entail 'not p', which would follow in classical logic. Likewise, the classical laws of distributivity and disjunctive syllogism fail for epistemic modals. Existing attempts to account for these facts generally either under- or over-correct. Some theories predict that (...) 'p and might not p', a so-called epistemic contradiction, is a contradiction only in an etiolated sense, under a notion of entailment that does not allow substitution of logical equivalents; these theories underpredict the infelicity of embedded epistemic contradictions. Other theories savage classical logic, eliminating not just rules that intuitively fail, like distributivity and disjunctive syllogism, but also rules like non-contradiction, excluded middle, De Morgan’s laws, and disjunction introduction, which intuitively remain valid for epistemic modals. In this paper, we aim for a middle ground, developing a semantics and logic for epistemic modals that makes epistemic contradictions genuine contradictions and that invalidates distributivity and disjunctive syllogism but that otherwise preserves classical laws that intuitively remain valid. We start with an algebraic semantics, based on ortholattices instead of Boolean algebras, and then propose a more concrete possibility semantics, based on partial possibilities related by compatibility. Both semantics yield the same consequence relation, which we axiomatize. Then we show how to extend our semantics to explain parallel phenomena involving probabilities and conditionals. The goal throughout is to retain what is desirable about classical logic while accounting for the non-classicality of epistemic vocabulary. (shrink)

This chapter argues that epistemologists should replace a “standard alternatives” picture of knowledge, assumed by many fallibilist theories of knowledge, with a new “multipath” picture of knowledge. The chapter first identifies a problem for the standard picture: fallibilists working with this picture cannot maintain even the most uncontroversial epistemic closure principles without making extreme assumptions about the ability of humans to know empirical truths without empirical investigation. The chapter then shows how the multipath picture, motivated by independent arguments, saves fallibilism (...) from this problem. The multipath picture is based on taking seriously the idea that there can be multiple paths to knowing some propositions about the world. An overlooked consequence of fallibilism is that these multiple paths to knowledge may involve ruling out different sets of alternatives, which should be represented in a fallibilist picture of knowledge. The chapter concludes by considering inductive knowledge and strong epistemic closure from this multipath perspective. (shrink)

In this paper, we explore semantics for comparative epistemic modals that avoid the entailment problems shown to result from Kratzer’s (1991) semantics by Yalcin (2006, 2009, 2010). In contrast to the alternative semantics presented by Yalcin and Lassiter (2010, 2011), based on finitely additive probability measures, we introduce semantics based on qualitatively additive measures, as well as semantics based on purely qualitative orderings, including orderings on propositions derived from orderings on worlds in the tradition of Kratzer (1991). All of these (...) semantics avoid the entailment problems that result from Kratzer’s semantics. Our discussion focuses on methodological issues concerning the choice between different semantics. (shrink)

This is the first modern edition of the works of Lady Mary Shepherd, one of the most important women philosophers of the early modern period. Shepherd has been widely neglected in the history of philosophy, but her work engaged with the dominant philosophers of the time - among them Hume, Berkeley, and Reid. In particular, her 1827 volume Essays on the Perception of an External Universe outlines a theory of causation, perception, and knowledge which Shepherd presents as an alternative (...) to what she sees as the mistaken views of Berkeley and Hume. What she ultimately presents is an original and systematic metaphysics and epistemology. Shepherd's Essays consists of two parts. The first is a theory of perception and knowledge of the external world, which is designed to rebut idealism and skepticism about the external world and show that our ordinary beliefs are based on reason. The second is a collection of essays on topics in metaphysics and epistemology, including the immateriality and eternity of the mind, the relationship between mind and body, the possibility of miracles, the association of ideas, the relationship between physical and mathematical reasoning, and the epistemology of testimony. Antonia LoLordo's edition of Shepherd's Essays includes scholarly notes throughout the text that provide historical and philosophical context and expand on the major concepts of Shepherd's system. Her extensive introduction to Shepherd's life and works surveys some of the major points of Shepherd's system, points out directions for future research, and offers guidance for readers planning to teach her work in their courses. This volume is an invaluable primary resource for scholars, graduate students, and undergraduates interested in metaphysics, epistemology, and early modern philosophy. (shrink)

Epistemic modal predicate logic raises conceptual problems not faced in the case of alethic modal predicate logic : Frege’s “Hesperus-Phosphorus” problem—how to make sense of ascribing to agents ignorance of necessarily true identity statements—and the related “Hintikka-Kripke” problem—how to set up a logical system combining epistemic and alethic modalities, as well as others problems, such as Quine’s “Double Vision” problem and problems of self-knowledge. In this paper, we lay out a philosophical approach to epistemic predicate logic, implemented formally in Melvin (...) Fitting’s First-Order Intensional Logic, that we argue solves these and other conceptual problems. Topics covered include: Quine on the “collapse” of modal distinctions; the rigidity of names; belief reports and unarticulated constituents; epistemic roles; counterfactual attitudes; representational vs. interpretational semantics; ignorance of co-reference vs. ignorance of identity; two-dimensional epistemic models; quantification into epistemic contexts; and an approach to multi-agent epistemic logic based on centered worlds and hybrid logic. (shrink)

Using data from a survey of certified organic or in-transition to organic vegetable and dairy producers in Canada, we seek to understand a farmer’s decision to convert to organic production by exploring the motives, problems and challenges, and benefits of transition to organic. Results suggest that health and safety concerns and environmental issues are the predominant motives for conversion, while economic motives are of lesser importance. In contrast to the extant literature, results suggest that the motives underlying transition have not (...) changed overtime in Canada. Problems experienced during transition relate to lack of governmental and institutional support, negative pressure from other farmers and farm groups, and lack of physical and financial capital. Reduced exposure to chemicals and improved food quality were highly ranked benefits, while economic related benefits were scored among the lowest of the listed benefits. To prosper, the Canadian organic sector must overcome fundamental marketing problems and challenges. Promulgation of the Canada Organic standard may help address some marketing issues by providing more information to consumers. (shrink)

This chapter, which examines the unity shared between what appear to be conflicting modes of natural investigation, an often neglected aspect of the history of British natural philosophy, also discusses the views of Francis Bacon on observation and experiment and describes his system of the sciences. It looks at aspects of Bacon's program for natural philosophy that made critics set the divide Baconian natural philosophy and the mathematical sciences of the seventeenth century. The chapter furthermore highlights the role of the (...) Baconian system of the sciences in the acceptance of Isaac Newton's Principia mathematica. (shrink)

According to the Principle of the Fixity of the Past (FP), no one can now do anything that would require the past to have unfolded differently than it actually did, for the past is fixed, over and done with. Why might doing something in the future require the past to be different? Because if determinism is true—if the laws of nature and the initial conditions of the Big Bang determined a unique future for our universe—then doing anything other than what (...) you are determined to do would require one of two things: either a miracle, a violation of the actual laws of nature, or a different past, all the way back to the Big Bang or beyond. Which would it be? Those who reject miracles accept a Backtracking Principle (BT), according to which the past would (have to) be different. If this is correct, then it follows by (FP) that you cannot now do anything other than what you are determined to do. The conclusion of this much-discussed argument is that the freedom to do otherwise is incompatible with determinism. In order to break a stalemate between incompatibilists and compatibilists in the debate over (FP), this article presents a new Action-Type Argument for (FP). The aim is to refute Backtracking Compatibilism, the view that (BT) is true and yet the freedom to do otherwise is compatible with determinism. The form of the Action-Type Argument for (FP) also leads to a Simple Argument for incompatibilism, which does not assume (BT). What the Simple Argument does assume is a “governing” view of laws of nature, a view of laws as more than mere regularities that turn out to be exceptionless over all time. Incompatibilism follows. (shrink)

«Claros del bosque» es uno de los libros esenciales de la trayectoria filosófica de María Zambrano en el que vemos, por primera vez, en marcha su «razón poética». Nadie mejor que la propia autora para presentarnos el significado de esta obra: “«Claros del bosque» dentro de mi pensamiento vertido en lo impreso, salvo alguna excepción, aparece como algo inédito salido de ese escribir irreprimible que brota por sí mismo y que ha ido a parar a cuadernos y hojas que nadie (...) conoce, ni yo misma, reacia que soy a releerme. Tenía que suceder por fuerza. Mas creo que el carácter de ofrenda de «Claros del bosque» a la persona a quien va dedicado en su tránsito tiene que ver en ello, acentuando así el carácter de ofrenda que todo lo que he publicado tiene desde siempre. Nada es de extrañar que la razón discursiva apenas aparezca. Con anterioridad esbocé una ‘Crítica de la razón discursiva’ que no podría prometerme que salga de ese estado. Creo, pues, que como libro es el que más responde a esa ‘idea’ hace tiempo formulada de que ‘pensar es ante todo –como raíz, como acto–– descifrar lo que se siente’, entendiendo por sentir el ‘sentir originario’, expresión usada por mí desde hace años. Y también que ‘el hombre es el ser que padece su propia trascendencia’ en un incesante proceso de unificación entre pasividad y conocimiento, entre ser y vida. Vida verdadera, sorprendida tan sólo en algunos claros que se abren en la espesura inicial entre cielo y tierra. Y en el remoto horizonte donde cielo y tierra, ser y vida, vida y muerte se anegan”. (shrink)

In two of the earliest papers on extending modal logic with propositional quantifiers, R. A. Bull and K. Fine studied a modal logic S5Π extending S5 with axioms and rules for propositional quantification. Surprisingly, there seems to have been no proof in the literature of the completeness of S5Π with respect to its most natural algebraic semantics, with propositional quantifiers interpreted by meets and joins over all elements in a complete Boolean algebra. In this note, we give such a proof. (...) This result raises the question: For which normal modal logics. (shrink)

In this article, we tell a story about incompleteness in modal logic. The story weaves together an article of van Benthem, “Syntactic aspects of modal incompleteness theorems,” and a longstanding open question: whether every normal modal logic can be characterized by a class of completely additive modal algebras, or as we call them, ${\cal V}$-baos. Using a first-order reformulation of the property of complete additivity, we prove that the modal logic that starred in van Benthem’s article resolves the open question (...) in the negative. In addition, for the case of bimodal logic, we show that there is a naturally occurring logic that is incomplete with respect to ${\cal V}$-baos, namely the provability logic $GLB$. We also show that even logics that are unsound with respect to such algebras do not have to be more complex than the classical propositional calculus. On the other hand, we observe that it is undecidable whether a syntactically defined logic is ${\cal V}$-complete. After these results, we generalize the Blok Dichotomy to degrees of ${\cal V}$-incompleteness. In the end, we return to van Benthem’s theme of syntactic aspects of modal incompleteness. (shrink)

The reasoning abilities of large language models (LLMs) are the topic of a growing body of research in artificial intelligence and cognitive science. In this paper, we probe the extent to which a dozen LLMs are able to distinguish logically correct inferences from logically fallacious ones. We focus on inference patterns involving conditionals (e.g., 'If Ann has a queen, then Bob has a jack') and epistemic modals (e.g., 'Ann might have an ace', 'Bob must have a king'). These inference patterns (...) have been of special interest to logicians, philosophers, and linguists, since they plausibly play a central role in human reasoning. Assessing LLMs on these inference patterns is thus highly relevant to the question of how much the reasoning abilities of LLMs match those of humans. Among the LLMs we tested, all but GPT-4 often make basic mistakes with conditionals. Moreover, even GPT-4 displays logically inconsistent judgments across inference patterns involving epistemic modals. (shrink)

This article explores the ways in which naturism articulates a set of relationships between the body and nature. We begin by sketching the histories of some Western naturist movements, tracing their lineage back to 19th-century life reform movements and through into inter-war reorientations of citizenship and morality. We consider the problematic of the naked body's relationship to the erotic (and specifically to the erotics of nature), drawing on some materials on outdoor sex; set alongside this is a discussion of the (...) regenerative use of wilderness in the mythopoetic men's movement. These strands are finally drawn together in order to consider the complex negotiation of discourses of nature, human nature, the natural body and the natural landscape - a negotiation embodied in naturism. (shrink)

The picture of information acquisition as the elimination of possibilities has proven fruitful in many domains, serving as a foundation for formal models in philosophy, linguistics, computer science, and economics. While the picture appears simple, its formalization in dynamic epistemic logic reveals subtleties: given a valid principle of information dynamics in the language of dynamic epistemic logic, substituting complex epistemic sentences for its atomic sentences may result in an invalid principle. In this article, we explore such failures of uniform substitution. (...) First, we give epistemic examples inspired by Moore, Fitch, and Williamson. Second, we answer affirmatively a question posed by van Benthem: can we effectively decide when every substitution instance of a given dynamic epistemic principle is valid? In technical terms, we prove the decidability of this schematic validity problem for public announcement logic (PAL and PAL-RC) over models for finitely many fully introspective agents, as well as models for infinitely many arbitrary agents. The proof of this result illuminates the reasons for the failure of uniform substitution. (shrink)

In this paper, we introduce an extension of the modal language with what we call the global quantificational modality [∀p]. In essence, this modality combines the propositional quantifier ∀p with the global modality A: [∀p] plays the same role as the compound modality ∀pA. Unlike the propositional quantifier by itself, the global quantificational modality can be straightforwardly interpreted in any Boolean Algebra Expansion (BAE). We present a logic GQM for this language and prove that it is complete with respect to (...) the intended algebraic semantics. This logic enables a conceptual shift, as what have traditionally been called different “modal logics” now become [∀p]-universal theories over the base logic GQM: instead of defining a new logic with an axiom schema such as □φ→□□φ, one reasons in GQM about what follows from the globally quantified formula [∀p](□p→□□p). (shrink)

Viewing the language of modal logic as a language for describing directed graphs, a natural type of directed graph to study modally is one where the nodes are sets and the edge relation is the subset or superset relation. A well-known example from the literature on intuitionistic logic is the class of Medvedev frames $\langle W,R\rangle$ where $W$ is the set of nonempty subsets of some nonempty finite set $S$, and $xRy$ iff $x\supseteq y$, or more liberally, where $\langle W,R\rangle$ (...) is isomorphic as a directed graph to $\langle \wp(S)\setminus\{\emptyset\},\supseteq\rangle$. Prucnal [32] proved that the modal logic of Medvedev frames is not finitely axiomatizable. Here we continue the study of Medvedev frames with extended modal languages. Our results concern definability. We show that the class of Medvedev frames is definable by a formula in the language of tense logic, i.e., with a converse modality for quantifying over supersets in Medvedev frames, extended with any one of the following standard devices: nominals (for naming nodes), a difference modality (for quantifying over those $y$ such that $x\not= y$), or a complement modality (for quantifying over those $y$ such that $x\not\supseteq y$). It follows that either the logic of Medvedev frames in one of these tense languages is finitely axiomatizable---which would answer the open question of whether Medvedev's [31] "logic of finite problems'' is decidable---or else the minimal logics in these languages extended with our defining formulas are the beginnings of infinite sequences of frame-incomplete logics. (shrink)

Following a proposal of Humberstone, this paper studies a semantics for modal logic based on partial “possibilities” rather than total “worlds.” There are a number of reasons, philosophical and mathematical, to find this alternative semantics attractive. Here we focus on the construction of possibility models with a finitary flavor. Our main completeness result shows that for a number of standard modal logics, we can build a canonical possibility model, wherein every logically consistent formula is satisfied, by simply taking each individual (...) finite formula (modulo equivalence) to be a possibility, rather than each infinite maximally consistent set of formulas as in the usual canonical world models. Constructing these locally finite canonical models involves solving a problem in general modal logic of independent interest, related to the study of adjoint pairs of modal operators: for a given modal logic L, can we find for every formula φ a formula f(φ) such that for every formula ψ, φ → []ψ is provable in L if and only if f(φ) → ψ is provable in L? We answer this question for a number of standard modal logics, using model-theoretic arguments with world semantics. This second main result allows us to build for each logic a canonical possibility model out of the lattice of formulas related by provable implication in the logic. (shrink)

Ernst Tugendhat’s critique of Martin Heidegger’s conception of truth is an ongoing topic in Heideggerian scholarship. In this paper, I contribute to the ongoing exchange between defenders of Heidegger and those who are in agreement with Tugendhat. Specifically, I contend that Tugendhat’s criticisms fail to situate Heidegger’s account of truth within his broader phenomenological–hermeneutic project. In the end, Tugendhat’s critique is grounded upon philosophical assumptions that Heidegger is bringing under question by rethinking the concept of truth. I suggest that thinking (...) through Tugendhat’s critique and attempting to formulate an adequate Heideggerian response gives us a richer understanding of both Heidegger’s account of truth and his general philosophical project. (shrink)