This book is a defense of modal realism; the thesis that our world is but one of a plurality of worlds, and that the individuals that inhabit our world are only a few out of all the inhabitants of all the worlds. Lewis argues that the philosophical utility of modal realism is a good reason for believing that it is true.

Some of the most eminent and enduring philosophical questions concern matters of priority: what is prior to what? What 'grounds' what? Is, for instance, matter prior to mind? Recently, a vivid debate has arisen about how such questions have to be understood. Can the relevant notion or notions of priority be spelled out? And how do they relate to other metaphysical notions, such as modality, truth-making or essence? This volume of new essays, by leading figures in contemporary metaphysics, is (...) the first to address and investigate the metaphysical idea that certain facts are grounded in other facts. An introduction introduces and surveys the debate, examining its history as well as its central systematic aspects. The volume will be of wide interest to students and scholars of metaphysics. (shrink)

A strongly deterministic theory of physics is one that permits exactly one possible history of the universe. In the words of Penrose (1989), "it is not just a matter of the future being determined by the past; the entire history of the universe is fixed, according to some precise mathematical scheme, for all time.” Such an extraordinary feature may appear unattainable in a world like ours. In this paper, I show that it can be achieved in a simple way (...) and discuss its implications for metaphysics and philosophy of science, including natural properties, free will, explanation, and modality. First, I propose a precise definition of strong determinism. Next, I discuss its philosophical ramifications and a toy example. Finally, I provide a realistic example of a strongly deterministic (and simple) physical theory---the Everettian Wentaculus. A surprising consequence is that whether or not our world is strongly deterministic may be empirically underdetermined. (shrink)

The topic of a priori knowledge is approached through the theory of evidence. A shortcoming in traditional formulations of moderate rationalism and moderate empiricism is that they fail to explain why rational intuition and phenomenal experience count as basic sources of evidence. This explanatory gap is filled by modal reliabilism -- the theory that there is a qualified modal tie between basic sources of evidence and the truth. This tie to the truth is then explained by the (...) theory of concept possession: this tie is a consequence of what, by definition, it is to possess (i.e., to understand) one’s concepts. A corollary of the overall account is that the a priori disciplines (logic, mathematics, philosophy) can be largely autonomous from the empirical sciences. (shrink)

Justification as Ignorance offers an original account of epistemic justification as both non-factive and luminous, vindicating core internalist intuitions without construing justification as an internal condition knowable by reflection alone. Sven Rosenkranz conceives of justification, in its doxastic and propositional varieties, as a kind of epistemic possibility of knowing and of being in a position to know. His account contrasts with recent alternative views that characterize justification in terms of the metaphysical possibility of knowing. Instead, he develops a suitable non-normal (...) multi-modal epistemic logic for knowledge and being in a position to know that respects the finding that these notions create hyperintensional contexts. He also defends his conception of justification against well-known anti-luminosity arguments, shows that the account allows for fruitful applications and principled solutions to the lottery and preface paradoxes, and provides a metaphysics of justification and its varying degrees of strength that is compatible with core assumptions of the knowledge-first approach and disjunctivist conceptions of mental states. (shrink)

There are three theories in the epistemology of modality that have received sustained attention over the past 20 years: conceivability-theory, counterfactual-theory, and deduction-theory. In this paper we argue that all three face what we call the problem of modal epistemic friction. One consequence of the problem is that for any of the three accounts to yield modal knowledge, the account must provide an epistemology of essence. We discuss an attempt to fend off the problem within (...) the context of the internalism versus externalism debate about epistemic justification. We then investigate the effects that the PMEF has on reductive and non-reductive theories of the relation between essence and modality. (shrink)

This paper provides a defense of two traditional theses: the Autonomy of Philosophy and the Authority of Philosophy. The first step is a defense of the evidential status of intuitions (intellectual seemings). Rival views (such as radical empiricism), which reject the evidential status of intuitions, are shown to be epistemically self-defeating. It is then argued that the only way to explain the evidential status of intuitions is to invoke modal reliabilism. This theory requires that intuitions have a certain qualified (...) modal tie to the truth. This result is then used as the basis of the defense of the Autonomy and Authority theses. The paper closes with a defense of the two theses against a potential threat from scientific essentialism. (shrink)

Contents: 1) Peter Kung, Why We Need Something Like Imagery; 2) Derek Lam, An Imaginative Person’s Guide to Objective Modality; 3) Rebecca Hanrahan, Crossing Rivers: Imagination and Real Possibilities; 4) Michael Omoge, Imagination, Metaphysical Modality, and Modal Psychology; 5) Joshua Myers, Reasoning with Imagination; 6) Franz Berto, Equivalence in Imagination; 7) Christopher Badura, How Imagination Can Justify; 8) Antonella Mallozzi, Imagination, Inference, and Apriority; 9) Margherita Arcangeli, Narratives and Thought Experiments: Restoring the Role of Imagination; 10) Margot Strohminger, (...) Two Ways of Imagining Galileo’s Experiment; 11) Eric Peterson, Attention to Details: Imagination, Attention, and Epistemic Significance; 12) Amy Kind, Bridging the Divide: Imagining Across Experiential Perspectives; 13) Julia Langkau, On Imagining Being Someone Else; 14) Luke Roelofs, “Imagine If They Did That to You!”: The Complexity of Empathy; 15) Nick Wiltsher and Bence Nanay, Imagination, Selves, and Knowledge of Self: Pessoa’s Dreams in The Book of Disquiet . (shrink)

Scientific essentialism is the view that some necessities can be known only with the aid of empirical science. The thesis of the paper is that scientific essentialism does not extend to the central questions of philosophy and that these questions can be answered a priori. The argument is that the evidence required for the defense of scientific essentialism is reliable only if the intuitions required by philosophy to answer its central questions is also reliable. Included is an outline of a (...) modal reliabilist theory of basic evidence and a concept-possession account of the reliability of a priori intuition. (shrink)

We describe a general logical framework, Justification Logic, for reasoning about epistemic justification. Justification Logic is based on classical propositional logic augmented by justification assertions t: F that read t is a justification for F. Justification Logic absorbs basic principles originating from both mainstream epistemology and the mathematical theory of proofs. It contributes to the studies of the well-known Justified True Belief vs. Knowledge problem. We state a general Correspondence Theorem showing that behind each epistemic modal logic, there (...) is a robust system of justifications. This renders a new, evidence-based foundation for epistemic logic. As a case study, we offer a resolution of the GoldmanRed Barns in Justification Logic. Furthermore, we formalize the well-known Gettier example and reveal hidden assumptions and redundancies in Gettier’s reasoning. (shrink)

My aim in this paper is to sketch, with a broad brush and in bare outlines, an approach to modal epistemology that is characterized by three distinctive features. First, the approach is agency-based: it locates the roots of our modal thought and knowledge in our experience of our own agency. Second, the approach is ambitious in that it takes the experience of certain modal properties in agency to be the sole distinctive feature of specifically modal thought and knowledge; (...) everything that we know about modality beyond the experience of agency is a matter of applying standard methods of inquiry such as deduction, induction and abductive methods for choosing between theories. Third, the account holds that modal thought and knowledge is, first and foremost, about modal properties that are sufficiently like those encountered in agency. (shrink)

This book contributes to two debates and it does so by bringing them together. The first is a debate in metaethics concerning normative reasons, the considerations that serve to justify a person’s actions and attitudes. The second is a debate in epistemology concerning the norms for belief, the standards that govern a person’s beliefs and by reference to which they are assessed. The book starts by developing and defending a new theory of reasons for action, that is, of practical (...) reasons. The theory belongs to a family that analyses reasons by appeal to the normative notion of rightness (fittingness, correctness); it is distinctive in making central appeal to modal notions, specifically, that of a nearby possible world. The result is a comprehensive framework that captures what is common to and distinctive of reasons of various kinds: justifying and demanding; for and against, possessed and unpossessed; objective and subjective. The framework is then generalized to reasons for belief, that is, to epistemic reasons, and combined with a substantive, first-order commitment, namely, that truth is the sole right-maker for belief. The upshot is an account of the various norms governing belief, including knowledge and rationality, and the relations among them. According to it, the standards to which belief is subject are various, but they are unified by an underlying principle. (shrink)

The paper elaborates upon various points and arguments in the author’s “A Priori Knowledge and the Scope of Philosophy” (Philosophical Studies, 1993), in which the author defends the autonomy of philosophy from the empirical sciences. It provides, for example, an extended defense of the modal reliabilist theory of basic evidence, including a new argument against evolutionary explanations of the reliability of intuitions. It also contains a fuller discussion of how to neutralize the threat of scientific essentialism to the (...) autonomy of philosophy. (shrink)

The chapter discusses the issue of how we may achieve knowledge of essence. It offers a critical survey of the main theories of knowledge of essence that have been proposed within contemporary debates, particularly by Lowe, Hale, Oderberg, Elder, and Kment.

This monograph explores the logical systems of early logicians in the Arabic tradition from a theoretical perspective, providing a complete panorama of early Arabic logic and centering it within an expansive historical context. By thoroughly examining the writings of the first Arabic logicians, al-Fārābī, Avicenna and Averroes, the author analyzes their respective theories, discusses their relationship to the syllogistics of Aristotle and his followers, and measures their influence on later logical systems. Beginning with an introduction to the writings of the (...) most prominent Arabic logicians, the author scrutinizes these works to determine their categorical logic, as well as their modal and hypothetical logics. Where most other studies written on this subject focus on the Arabic logicians’ epistemology, metaphysics, and theology, this volume takes a unique approach by focusing on the actual technical aspects and features of their logics. The author then moves on to examine the original texts as closely as possible and employs the symbolism of modern propositional, predicate, and modal logics, rendering the arguments of each logician clearly and precisely while clarifying the theories themselves in order to determine the differences between the Arabic logicians’ systems and those of Aristotle. By providing a detailed examination of theories that are still not very well-known in Western countries, the author is able to assess the improvements that can be found in the Arabic writings, and to situate Arabic logic within the breadth of the history of logic. This unique study will appeal mainly to historians of logic, logicians, and philosophers who seek a better understanding of the Arabic tradition. It also will be of interest to modern logicians who wish to delve into the historical aspects and progression of their discipline. Furthermore, this book will serve as a valuable resource for graduate students who wish to complement their general knowledge of Arabic culture, logic, and sciences. (shrink)

Medical practice is practiced morality, and clinical research belongs to normative ethics. The present book elucidates and advances this thesis by: 1. analyzing the structure of medical language, knowledge, and theories; 2. inquiring into the foundations of the clinical encounter; 3. introducing the logic and methodology of clinical decision-making, including artificial intelligence in medicine; 4. suggesting comprehensive theories of organism, life, and psyche; of health, illness, and disease; of etiology, diagnosis, prognosis, prevention, and therapy; and 5. investigating the moral (...) and metaphysical issues central to medical practice and research. Many systems of (classical, modal, non-classical, probability, and fuzzy) logic are introduced and applied. Fuzzy medical deontics, fuzzy medical ontology, fuzzy medical concept formation, fuzzy medical decision-making and biomedicine and many other techniques of fuzzification in medicine are introduced for the first time. -/- . (shrink)

The aim of this book is to present the fundamental theoretical results concerning inference rules in deductive formal systems. Primary attention is focused on: admissible or permissible inference rules the derivability of the admissible inference rules the structural completeness of logics the bases for admissible and valid inference rules. There is particular emphasis on propositional non-standard logics (primary, superintuitionistic and modal logics) but general logical consequence relations and classical first-order theories are also considered. The book is basically self-contained and special (...) attention has been made to present the material in a convenient manner for the reader. Proofs of results, many of which are not readily available elsewhere, are also included. The book is written at a level appropriate for first-year graduate students in mathematics or computer science. Although some knowledge of elementary logic and universal algebra are necessary, the first chapter includes all the results from universal algebra and logic that the reader needs. For graduate students in mathematics and computer science the book is an excellent textbook. (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)

I argue that philosophy is like science in three interesting and non-obvious ways. First, the claims made by philosophy are synthetic, not analytic: philosophical claims, just like scientific claims, are not guaranteed by the structure of the concepts they involve. Second, philosophical knowledge is a posteriori, not a priori: the claims established by philosophers depend on the same kind of empirical support as scientific theories. And finally, the central questions of philosophy concern actuality rather than necessity: philosophy is primarily (...) aimed at understanding the actual world studied by science, not some further realm of metaphysical modality. (shrink)

Reasons and reasoning were central to the work of Paul Grice, one of the most influential and admired philosophers of the late twentieth century. In the John Locke Lectures that Grice delivered in Oxford at the end of the 1970s, he set out his fundamental thoughts about these topics; Aspects of Reason is the long-awaited publication of those lectures. This immensely rich work, powerfully evocative of the mind of its author, will refresh and illuminate discussions in many areas of contemporary (...) philosophy. (shrink)

In ‘belief revision’ a theory is revised with a formula φ resulting in a revised theory . Typically, is in , one has to give up belief in by a process of retraction, and φ is in . We propose to model belief revision in a dynamic epistemic logic. In this setting, we typically have an information state (pointed Kripke model) for the theory wherein the agent believes the negation of the revision formula, i.e., wherein is true. (...) The revision with φ is a program *φ that transforms this information state into a new information state. The transformation is described by a dynamic modal operator [*φ], that is interpreted as a binary relation [ [*φ] ] between information states. The next information state is computed from the current information state and the belief revision formula. If the revision is successful, the agent believes φ in the resulting state, i.e., Bφ is then true. To make this work, as information states we propose ‘doxastic epistemic models’ that represent both knowledge and degrees of belief. These are multi-modal and multi-agent Kripke models. They are constructed from preference relations for agents, and they satisfy various characterizable multi-agent frame properties. Iterated, revocable, and higher-order belief revision are all quite natural in this setting. We present, for an example, five different ways of such dynamic belief revision. One can also see that as a non-deterministic epistemic action with two alternatives, where one is preferred over the other, and there is a natural generalization to general epistemic actions with preferences. (shrink)

Whether computational algorithms such as latent semantic analysis (LSA) can both extract meaning from language and advance theories of human cognition has become a topic of debate in cognitive science, whereby accounts of symbolic cognition and embodied cognition are often contrasted. Albeit for different reasons, in both accounts the importance of statistical regularities in linguistic surface structure tends to be underestimated. The current article gives an overview of the symbolic and embodied cognition accounts and shows how meaning induction attributed to (...) a specific statistical process or to activation of embodied representations should be attributed to language itself. Specifically, the performance of LSA can be attributed to the linguistic surface structure, more than special characteristics of the algorithm, and embodiment findings attributed to perceptual simulations can be explained by distributional linguistic information. (shrink)

Over the past two decades, modal epistemology has turned its attention to ordinary modal knowledge. This paper brings to the fore a neglected but central form of ordinary modal knowledge: knowledge of agentive modality, and in particular of our own abilities, which I call ‘ability knowledge’. I argue that modal epistemology as it is does not account for ability knowledge, by looking at the most promising candidate theories: perception-based, counterfactual-based, and similarity-based modal epistemologies. I (...) then outline a more promising epistemology for our ability knowledge, which relies on the experience of our own agency, and draw out some lessons for modal epistemology in general. (shrink)

Philosophers have recently highlighted substantial affinities between causation and grounding, which has inclined some to import the conceptual and formal resources of causal interventionism into the metaphysics of grounding. The prospect of grounding interventionism raises two important questions: exactly what are grounding interventions, and why should we think they enable knowledge of grounding? This paper will approach these questions by examining how causal interventionists have addressed (or might address) analogous questions and then comparing the available options for grounding interventionism. (...) I argue that grounding interventions must be understood in worldly terms, as adding something to or deleting something from the roster of entities, or making some fact obtain or fail to obtain. I consider three bases for counterfactual assessment: imagination, structural equation models, and background theory. I conclude that grounding interventionism requires firmer epistemological foundations, without which the interventionist's epistemology of grounding is incomplete and ineffectually rationalist. (shrink)

Frege puzzles exploit cognitive differences between co-referential terms. Traditionally, they were handled by some version of Frege’s distinction between sense and reference, which avoided disruptive consequences for epistemology. However, the Fregean programme did not live up to its original promise, and was undermined by the development of theories of direct reference; for semantic purposes, its prospects now look dim. In particular, well-known analogues of Frege puzzles concern pairs of uncontentious synonyms; attempts to deal with them by distinguishing idiolects or postulating (...) ‘narrow contents’ or elaborate forms of context-sensitivity are inadequate or semantically implausible. Although ascriptions of knowledge, belief, and other attitudes are ubiquitous in epistemology, epistemologists have not properly come to terms with the surprising consequences of anti-Fregean semantic accounts of attitude ascriptions. In ‘A Puzzle about Belief ’, Saul Kripke shows that natural-seeming disquotational principles for ascribing belief lead to apparently unacceptable consequences, including outright contradictions, in problem cases. Such disquotation principles, I argue, are best regarded not as conceptual connections but just as heuristics in the psychological sense, quick and easy ways of assessing belief ascriptions, usually accurate under normal conditions but far from 100% reliable. I discuss similar heuristics for ascribing knowledge and other attitudes. That the principles have a merely heuristic status need not be pre-theoretically manifest to their users. This view vindicates Kripke’s conclusion that it would be wrong-headed to draw semantic conclusions from Frege puzzles. I discuss the epistemological consequences of an anti-Fregean approach to Frege puzzles, including for Kripke’s cases of the contingent a priori and the necessary a posteriori, but also for evidence, for epistemic modalities, and for epistemic and subjective conceptions of probability. Anna Mahtani’s recent identification of Frege puzzles for the ex ante Pareto Principle as used in welfare economics provides an interesting example. I suggest a model-building methodology as the most promising way of handling at least some of the difficulties. A final issue is the choice between different anti-Fregean approaches to semantics, from very coarse-grained intensional approaches on which sentences express functions from possible worlds to truth-values to more fine-grained hyperintensional approaches on which sentences express functions from possible or impossible worlds to truth-values or else Russellian structured propositions. Some of the hyperintensional theories violate semantic compositionality. More generally, since our attitude ascriptions rely on heuristics, they should be expected to exhibit some level of error; although hyperintensional approaches may be able slightly to reduce the level of postulated error, they do so at the cost of vastly increased theoretical complexity, and so have weak explanatory power. Methodologically, a simple intensional approach does better. (shrink)

A very influential idea in the epistemology of modality is that we acquire knowledge of metaphysical modality through knowledge of essence. As a consequence, the epistemology of essence becomes crucial in the attempt to answer the question of how we come to know modal propositions. In this paper I investigate Lowe’s and Hale’s approach to the epistemology of essence and argue that both of them remain in a crucial, structural sense incomplete. Systematizing this criticism against Lowe (...) and Hale, I then break down desiderata of what I call a structurally complete picture of the epistemology of essence. Finally, I discuss Husserl’s epistemology of essence and defend it against a notorious objection. However, Husserl’s approach also seems to remain incomplete, due to its appeal to imagination, which operates on the basis of background assumptions that are themselves in need of justification. I indicate, however, that a Husserlian theory of intuitive awareness of universals might supply us with (direct) justification of these background assumptions and, hence, that we might be able to paint a structurally complete picture of the epistemology of essence with Husserlian means. (shrink)

Epistemic logic has become a major field of philosophical logic ever since the groundbreaking work by Hintikka [58]. Despite its various successful applications in theoretical computer science, AI, and game theory, the technical development of the field has been mainly focusing on the propositional part, i.e., the propositional modal logics of “knowing that”. However, knowledge is expressed in everyday life by using various other locutions such as “knowing whether”, “knowing what”, “knowing how” and so on (knowing-wh hereafter). Such (...) knowledge expressions are better captured in quantified epistemic logic, as was already discussed by Hintikka [58] and his sequel works at length. This paper aims to draw the attention back again to such a fascinating but largely neglected topic. We first survey what Hintikka and others did in the literature of quantified epistemic logic, and then advocate a new quantifier-free approach to study the epistemic logics of knowing-wh, which we believe can balance expressivity and complexity, and capture the essential reasoning patterns about knowing-wh. We survey our recent line of work on the epistemic logics of ‘knowing whether”, “knowing what” and “knowing how” to demonstrate the use of this new approach. (shrink)

Modal intuitions are the primary source of modal knowledge but also of modal error. According to the theory of modal error in this paper, modal intuitions retain their evidential force in spite of their fallibility, and erroneous modal intuitions are in principle identifiable and eliminable by subjecting our intuitions to a priori dialectic. After an inventory of standard sources of modal error, two further sources are examined in detail. The first source - namely, the failure to distinguish between (...) metaphysical possibility and various kinds of epistemic possibility - turns out to be comparatively easy to untangle and poses little threat to intuition-driven philosophical investigation. The second source is the local misunderstanding of one's concepts . This pathology may be understood on analogy with a patient who is given a clean bill of health at his annual check-up, despite his having a cold at the time of the check-up: although the patient's health is locally disrupted, his overall health is sufficiently good to enable him to overcome the cold without external intervention. Even when our understanding of certain pivotal concepts has lapsed locally, our larger body of intuitions is sufficiently reliable to allow us, without intervention, to ferret out the modal errors resulting from this lapse of understanding by means of dialectic and/or a process of a priori reflection. This source of modal error, and our capacity to overcome it, has wide-ranging implications for philosophical method - including, in particular, its promise for disarming skepticism about the classical method of intuition-driven investigation itself. Indeed, it is shown that skeptical accounts of modal error are ultimately self-defeating. (shrink)

Between Saying and Doing aims to reconcile pragmatism with analytic philosophy. It investigates the relations between the meaning of linguistic expressions and their use. Giving due weight both to what one has to do in order to count as saying various things and to what one needs to say in order to specify those doings, makes it possible to shed new light on the relations between semantics and pragmatics. Among the vocabularies whose interrelated use and meaning are considered are: logical, (...) indexical, modal, normative, and intentional vocabulary. As the argument proceeds, new ways of thinking about the classic analytic core programs of empiricism, naturalism, and functionalism are offered, as well as novel insights about the ideas of artificial intelligence, the nature of logic, and intentional relations between subjects and objects. (shrink)

In this paper, we will re-elaborate the notions of filter bubble and of echo chamber by considering human cognitive systems’ limitations in everyday interactions and how they experience digital technologies. Researchers who applied the concept of filter bubble and echo chambers in empirical investigations see them as forms of algorithmically-caused systems that seclude the users of digital technologies from viewpoints and opinions that oppose theirs. However, a significant majority of empirical research has shown that users do find and interact with (...) opposing views. Furthermore, we argue that the notion of filter bubble overestimates the social impact of digital technologies in explaining social and political developments without considering the not-only-technological circumstances of online behavior and interaction. This provides us with motivation to reconsider this notion’s validity and re-elaborate it in light of existing epistemological theories that deal with the discomfort people experience when dealing with what they do not know. Therefore, we will survey a series of philosophical reflections regarding the epistemic limitations of human cognitive systems. In particular, we will discuss how knowledge and mere belief are phenomenologically indistinguishable and how people’s experience of having their beliefs challenged is cause of epistemic discomfort. We will then go on to argue, in contrast with Pariser’s assumptions, that digital media users might tend to conform to their held viewpoints because of the “immediate” way they experience opposing viewpoints. Since online people experience others and their viewpoints as material features of digital environments, we maintain that this modality of confronting oneself with contrasting opinions prompts users to reinforce their preexisting beliefs and attitudes. (shrink)

A disjunctive sentence like Olivia took Logic or Algebra conveys that Olivia didn’t take both classes and that the speaker doesn’t know which of the two classes she took. The corresponding sentence with a possibility modal, Olivia can take Logic or Algebra, conveys instead that she can take Logic and that she can take Algebra. These exclusivity, ignorance and free choice inferences are argued by many to be scalar implicatures. Recent work has looked at cases in which exclusivity and ignorance (...) appear to be computed instead at the presupposition level, independently from the assertion. On the basis of those data, Spector and Sudo :473–517, 2017) have argued for a hybrid account relying on a pragmatic principle for deriving implicatures in the presupposition. In this paper, we observe that a sentence like Noah is unaware that Olivia can take Logic or Algebra has a reading on which free choice appears in the presupposition, but not in the assertion, and we show that deriving this reading is challenging on Spector and Sudo’s hybrid account. Following the dialectic in Fox, we argue against a pragmatic approach to presupposition-based implicatures on the ground that it is not able to account for presupposed free choice. In addition, we raise a novel challenge for Spector and Sudo’s account coming from the conflicting presupposed ignorance triggered by sentences like #Noah is unaware that I have a son or a daughter, which is infelicitous even if it’s not common knowledge whether the speaker has a son or a daughter. More generally, our data reveals a systematic parallelism between the assertion and presupposition levels in terms of exclusivity, ignorance, and free choice. We argue that such parallels call for a unified analysis and we sketch how a grammatical theory of implicatures where meaning strengthening operates in a similar way at both levels :31–57, 2012; Magri in A theory of individual-level predicates based on blind mandatory scalar implicatures, MIT dissertation, 2009; Marty in Implicatures in the DP domain, MIT dissertation, 2017) can account for such parallels. (shrink)

The paper surveys the currently available axiomatizations of common belief (CB) and common knowledge (CK) by means of modal propositional logics. (Throughout, knowledge- whether individual or common- is defined as true belief.) Section 1 introduces the formal method of axiomatization followed by epistemic logicians, especially the syntax-semantics distinction, and the notion of a soundness and completeness theorem. Section 2 explains the syntactical concepts, while briefly discussing their motivations. Two standard semantic constructions, Kripke structures and neighbourhood structures, are introduced (...) in Sections 3 and 4, respectively. It is recalled that Aumann's partitional model of CK is a particular case of a definition in terms of Kripke structures. The paper also restates the well-known fact that Kripke structures can be regarded as particular cases of neighbourhood structures. Section 3 reviews the soundness and completeness theorems proved w.r.t. the former structures by Fagin, Halpern, Moses and Vardi, as well as related results by Lismont. Section 4 reviews the corresponding theorems derived w.r.t. the latter structures by Lismont and Mongin. A general conclusion of the paper is that the axiomatization of CB does not require as strong systems of individual belief as was originally thought- only monotonicity has thusfar proved indispensable. Section 5 explains another consequence of general relevance: despite the "infinitary" nature of CB, the axiom systems of this paper admit of effective decision procedures, i.e., they are decidable in the logician's sense. (shrink)

The stated subject of these lecture courses given by Husserlbetween 1910 and 1918is ‘reason, the word for the mental activities and accomplishments that govern knowledge, give it form and supply it with norms.’ They show their author still pursuing the course set out in the Logical Investigations up to the end of the second decade of the century and displaying utter consistency with stands that he began taking on meaning, analyticity, Platonism, manifolds, mathematics, psychologism, etc. in the 1890s. Thus, (...) they undermine many idées reçues about the development of his thought. The centerpiece of this work is an exploration of the realm of meaning. Moreover, they add new dimensions to standard discussions by taking readers back to the place where phenomenology and analytic philosophy diverged. They show that Husserl tangled long and hard with the very ideas that went into the making of the latter and offer a wealth of interesting insights into sense and meaning, theory of judgment, complete and incomplete meanings, states of affairs, extensional logic, the relationship between logic and mathematics, functions and arguments, propositional functions, quantification, existential generalization, the word ‘all,’ number theory, sets, modality, deductive theory, ideas that are still under discussion today. Prepared for oral delivery in the classroom, they are refreshingly lively and spontaneous. They are clearer, more explicit, and readable than the books Husserl published during his lifetime. (shrink)

This book presents and defends a large number of theses in ontology and meta-ontology. The meta-ontological theses are broadly Quinean: that existence or being is what is expressed by the existential quantifier of formal logic; that the variables the quantifiers bind are essentially third-person-singular pronouns; that the “ontological commitments” of a person or theory are best revealed when the sentences of the person or theory are translated into the quantifier-variable idiom. Much of the book is devoted to ontological, (...) as opposed to meta-ontological, questions: Are there things that do not exist—or even things that have no sort of being whatever? Are there universals—or, more generally, abstract objects? What sort of thing is a property (quality, attribute…)? What are the ontological commitments of modal discourse? Are there possible worlds? If there are, do some of them contain “non-actual” individuals? (The meta-ontology severely constrains the ontology. For example, a non-actual but possible individual is an individual thing that might exist but does not. Therefore, non-actual individuals do not exist. That is to say, there aren’t any.) The book closes with the presentation and defense of an ontology consistent with everything said in the earlier parts of the book. The central thesis of this ontology is that everything belongs to one of two ontological categories, substance and relation. Relations are universals, and propositions are special kinds of relation. Special consideration is given to the absence of sets from the ontology. (shrink)

Keith Hossack's thesis is that knowledge is a conceptually primitive and metaphysically fundamental relation between a mind and a fact. He argues that in terms of the simple relation of knowledge we can analyze central notions of epistemology, of semantics, of modality and a priori knowledge, of psychology, and of linguistics. He does so in a framework that includes a fairly rich faculty psychology and that stresses causation: knowledge can be caused by belief, but because (...) knowledge is simple, it is not any kind of belief. He regards his enterprise as metaphysics, and he proceeds in a rather grand manner. The beginning of his Preface might remind one of the opening paragraphs of Leibniz's The Monadology.If knowledge is a simple relation between minds and facts, then we want to know a bit about facts. Hossack takes facts to consist in universals being instantiated among things. He favours a view of universals as respects in which things resemble each other, but his theory is at least officially silent about which universals exist, leaving that as a matter for scientific inquiry. But he takes metaphysics to be a science. Here he is being coy, and it is worth making out how. Hossack uses multigrade relations; these are relations of no fixed polyadicity that for any natural number n may be instantiated by n things. Vectors are bearers of such relations. The relation among working men of uniting to form a union is a multigrade relation, and the founders of the International Workers of the World are a vector bearing this relation. (shrink)

Purpose – The purpose of this paper is to explore artificial moral agency by reflecting upon the possibility of a Moral Turing Test and whether its lack of focus on interiority, i.e. its behaviouristic foundation, counts as an obstacle to establishing such a test to judge the performance of an Artificial Moral Agent. Subsequently, to investigate whether an MTT could serve as a useful framework for the understanding, designing and engineering of AMAs, we set out to address fundamental challenges within (...) the field of robot ethics regarding the formal representation of moral theories and standards. Here, typically three design approaches to AMAs are available: top-down theory-driven models and bottom-up approaches which set out to model moral behaviour by means of models for adaptive learning, such as neural networks, and finally, hybrid models, which involve components from both top-down and bottom-up approaches to the modelling of moral agency. With inspiration from Allen and Wallace as well as Prior, we elaborate on theoretically driven approaches to machine ethics by introducing deontic tense logic. Finally, within this framework, we explore the character of human interaction with a robot which has successfully passed an MTT. Design/methodology/approach – The ideas in this paper reflect preliminary theoretical considerations regarding the possibility of establishing a MTT based on the evaluation of moral behaviour, which focusses on moral reasoning regarding possible actions. The thoughts reflected fall within the field of normative ethics and apply deontic tense logic to discuss the possibilities and limitations of artificial moral agency. Findings – The authors stipulate a formalisation of logic of obligation, time and modality, which may serve as a candidate for implementing a system corresponding to an MTT in a restricted sense. Hence, the authors argue that to establish a present moral obligation, we need to be able to make a description of the actual situation and the relevant general moral rules. Such a description can never be complete, as the combination of exhaustive knowledge about both situations and rules would involve a God eye’s view, enabling one to know all there is to know and take everything relevant into consideration before making a perfect moral decision to act upon. Consequently, due to this frame problem, from an engineering point of view, we can only strive for designing a robot supposed to operate within a restricted domain and within a limited space-time region. Given such a setup, the robot has to be able to perform moral reasoning based on a formal description of the situation and any possible future developments. Although a system of this kind may be useful, it is clearly also limited to a particular context. It seems that it will always be possible to find special cases in which a given system does not pass the MTT. This calls for a new design of moral systems with trust-related components which will make it possible for the system to learn from experience. Originality/value – It is without doubt that in the near future we are going to be faced with advanced social robots with increasing autonomy, and our growing engagement with these robots calls for the exploration of ethical issues and stresses the importance of informing the process of engineering ethical robots. Our contribution can be seen as an early step in this direction. (shrink)

According to the widely endorsed Knowledge Account of Assertion, the epistemic requirements on assertion are captured by the Knowledge Norm of Assertion, which requires speakers only to assert what they know. This paper proposes that in addition to the Knowledge Norm there is also an Epistemic Propositional Certainty Norm of Assertion, which enjoins speakers only to assert p if they believe that p on the basis of evidence which makes p an epistemic propositional certainty. The paper explains (...) how this propositional certainty norm accounts for a range of data related to the practice of assertion and defends the norm against general objections to certainty norms of assertion put forward by Duncan Pritchard, John Turri, and Timothy Williamson, by drawing on linguistic theories about epistemic modals and gradable predicate semantics. Together these considerations show that the prospects of a certainty account of assertion are much more promising than is usually assumed. (shrink)

Knowledge excludes luck. According to the received view, this intuition reveals that knowing is essentially modal in character. This paper demurs. Either knowledge does not exclude luck, or the entailment reveals nothing about its conceptual character. It is argued that knowledge excludesaccidentality, and that this notion is not modal but causal‐explanatory. There are three central tasks. The first is to explicate the concept of accident. The second is to argue that the concepts of luck and accident are (...) “intensionally distinct,” which is to say that no member of the intension of either holds on both. The third is to argue that an anti‐accident requirement on knowledge is preferable to an anti‐luck analogue on abductive grounds. (shrink)

somewhat like Henkin's nonstandard interpretation of higher-order logics, while the right semantics [or logical modalities is an analogue to the standard of type theory in Henkin's sense. interpretation Another possibility would be to follow W.V. Quine's advice to give up logi­ cal modalities as being beyond repair. Or we could also try to develop a logic of conceptual possibility, restricting the range of our "possible worlds" to those compatible with the transcendental presuppositions of our own conceptual sys­ tem. This (...) looks in fact like one of the most interesting possible theories I have dreamt of developing but undoubtedly never will. Its kinship with Kant's way of thinking should be obvious. Besides putting the entire enterprise of possible-worlds semantics into a perspective, we can also see that the actual history of possible-worlds seman­ tics is more complicated than it might first appear to be. For the standard in­ terpretation of modal logics has reared its beautiful head repeatedly in the writings of Stig Kanger, Richard Montague the pre-Montague-semantics theorist, and Nino Cocchiarella. (shrink)

In this paper, I propose a new way of understanding the space of possibilities in the field of mental content. The resulting map assigns separate locations to theories of content that have generally been lumped together on the more traditional map. Conversely, it clusters together some theories of content that have typically been regarded as occupying opposite poles. I make my points concrete by developing a taxonomy of theories of mental content, but the main points of the paper concern not (...) merely how to classify, but how to understand, the theories. Also, though the paper takes theories of mental content as a case study, much of the discussion is applicable to theories of other phenomena. To a first approximation, the difference between the traditional and the proposed taxonomies turns on whether we classify theories of content by, on the one hand, their implications for a non-redundant supervenience base for content facts (i.e., for facts about what contents thoughts have) or, on the other, by their constitutive accounts of content. By a "constitutive account," I mean the kind of elucidation of the nature of a phenomenon that theorists have tried to give for, for example, knowledge, justice, personal identity, consciousness, convention, heat, and limit. The tendency to taxonomize by supervenience base is encouraged, I suggest, by a failure to keep clearly in view a distinction between constitutive and modal determination. Many philosophers would accept that a constitutive account cannot be captured in purely modal terms. Giving a constitutive account is not the same as specifying modally necessary and sufficient conditions. Nevertheless, philosophers often try to cash constitutive claims in modal terms. A case in point is that theories of content tend to be conceptualized in terms of the theories' implications for a supervenience base for content facts. My thesis goes beyond the by-now somewhat familiar proposition that not all modal determinants of a phenomenon are constitutive determinants. One who has taken that point on board might nevertheless conceive of a philosophical account as an attempt to specify constitutive determinants of the target phenomenon that make up a non-redundant supervenience base for the phenomenon. Shoehorning a philosophical account into this form leaves out elements that are modally redundant, but may be explanatorily or ontologically significant. For example, when a constitutive account has multiple levels, the different levels will typically be modally redundant. Formulating the account as a specification of a supervenience base of constitutive determinants will therefore flatten the account into a single level. Many of my arguments can be illustrated by considering the place of normativity in the theory of content. The new taxonomy gives a distinct niche to normative theories of content - theories that explain a thought's having a certain content at least in part in terms of the obtaining of normative facts. By contrast, on a traditional map, normative theories are invisible as such because normative facts supervene on non-normative ones. (shrink)

This chapter contains sections titled: Recent Relativism Standard Semantics and Ordinary Truth Relativist Semantics and Ordinary Truth Issues of Commensurability References.

A priori reflection, common sense and intuition have proved unreliable sources of information about the world outside of us. So the justification for a theory of the categories must derive from the empirical support of the scientific theories whose descriptions it unifies and clarifies. We don’t have reliable information about the de re modal profiles of external things either because the overwhelming proportion of our knowledge of the external world is theoretical—knowledge by description rather than knowledge (...) by acquaintance. This undermines the traditional idea that to be an object of category C is to be an object with such- and-such characteristic possibilities of combination. But this is no loss because de re modal thought lacks utility for creatures like us. (shrink)

In Pantsar (2014), an outline for an empirically feasible epistemological theory of arithmetic is presented. According to that theory, arithmetical knowledge is based on biological primitives but in the resulting empirical context develops an essentially a priori character. Such contextual a priori theory of arithmetical knowledge can explain two of the three characteristics that are usually associated with mathematical knowledge: that it appears to be a priori and objective. In this paper it is argued (...) that it can also explain the ... (shrink)

To practice compassion, the recognition, understanding, and alleviation of patient suffering are of utmost importance. Nursing literature provides ample guidance about the nature and meaning and patients’ views about compassion and physical and psychological suffering. However, missing is the discussion about how nurses can achieve a deeper awareness of patients’ suffering to practice compassion. This paper aims to describe the relational inquiry nursing approach and illustrate how this approach can enable nurses to develop a deeper awareness of patient suffering. The (...) relational inquiry approach encompasses two components: a relational consciousness and inquiry as a form of action. Relational consciousness requires the nurses to focus on the concrete situations and relationships as well as recognize the intrapersonal, interpersonal, and contextual factors affecting the situations. The interpersonal factors are among and between the individuals, intrapersonal factors are within the individuals, and contextual factors are the hidden factors influencing the individuals and situations. Inquiry as an action requires a critical analysis of the experiences of individuals, situational contexts, and knowledge to inform the nursing care modalities and actions. This approach encourages nurses to use the philosophies of hermeneutic phenomenology, critical theory, and pragmatism. The phenomenological worldview allows nurses to interpret their own and patients’ experiences, the critical theory worldview allows nurses to examine the influence of social and cultural factors, and pragmatism allows nurses to question their prior knowledge and develop new knowledge in each situation. The relational inquiry approach allows nurses to develop a deeper understanding of patient suffering through building a therapeutic and trustworthy relationship, active listening, focusing on the details, and engaging in broad and situations specific inquiries to understand the patient narrative of suffering. Two case exemplars are shared to demonstrate how relational inquiry allowed nurses to move beyond recognizing physical suffering and understand patients’ emotional and psychological suffering. (shrink)

Perception is the ultimate source of our knowledge about contingent facts. It is an extremely important philosophical development that starting in the last quarter of the twentieth century, philosophers have begun to change how they think of perception. The traditional view of perception focussed on sensory receptors; it has become clear, however, that perceptual systems radically transform the output of these receptors, yielding content concerning objects and events in the external world. Adequate understanding of this process requires that we (...) think of perception in new ways—how it operates, the differences among the modalities, and integration of content provided by the individual senses. Philosophers have developed new analytic tools, and opened themselves up to new ways of thinking about the relationship of perception to knowledge. The Oxford Handbook of the Philosophy of Perception is a collection of entries by leading researchers that reviews these new directions in philosophical thought. The Introduction to the Handbook reviews the history of the subject from its beginnings in ancient Greece to the nineteenth century, and the way that science and philosophy have together produced new conceptions during the last hundred years. It shows how the new thinking about perception has led to a complex web of theories. (shrink)

This book concerns the foundations of epistemic modality and hyperintensionality and their applications to the philosophy of mathematics. David Elohim examines the nature of epistemic modality, when the modal operator is interpreted as concerning both apriority and conceivability, as well as states of knowledge and belief. The book demonstrates how epistemic modality and hyperintensionality relate to the computational theory of mind; metaphysical modality and hyperintensionality; the types of mathematical modality and hyperintensionality; to the (...) epistemic status of large cardinal axioms, undecidable propositions, and abstraction principles in the philosophy of mathematics; to the modal and hyperintensional profiles of the logic of rational intuition; and to the types of intention, when the latter is interpreted as a hyperintensional mental state. Chapter \textbf{2} argues for a novel type of expressivism based on the duality between the categories of coalgebras and algebras, and argues that the duality permits of the reconciliation between modal and hyperintensional cognitivism and modal and hyperintensional expressivism. Elohim develops a novel, topic-sensitive truthmaker semantics for dynamic epistemic logic, and develops a novel, dynamic two-dimensional semantics grounded in two-dimensional hyperintensional Turing machines. Chapter \textbf{3} provides an abstraction principle for two-dimensional (hyper-)intensions. Chapter \textbf{4} advances a topic-sensitive two-dimensional truthmaker semantics, and provides three novel interpretations of the framework along with the epistemic and metasemantic. Chapter \textbf{5} applies the fixed points of the modal $\mu$-calculus in order to account for the iteration of epistemic states in a single agent, by contrast to availing of modal axiom 4 (i.e. the KK principle). The fixed point operators in the modal $\mu$-calculus are rendered hyperintensional, which yields the first hyperintensional construal of the modal $\mu$-calculus in the literature and the first application of the calculus to the iteration of epistemic states in a single agent instead of the common knowledge of a group of agents. Chapter \textbf{6} advances a solution to the Julius Caesar problem based on Fine's `criterial' identity conditions which incorporate conditions on essentiality and grounding. Chapter \textbf{7} provides a ground-theoretic regimentation of the proposals in the metaphysics of consciousness and examines its bearing on the two-dimensional conceivability argument against physicalism. The topic-sensitive epistemic two-dimensional truthmaker semantics developed in chapters \textbf{2} and \textbf{4} is availed of in order for epistemic states to be a guide to metaphysical states in the hyperintensional setting. -/- Chapters \textbf{8-12} provide cases demonstrating how the two-dimensional hyperintensions of hyperintensional, i.e. topic-sensitive epistemic two-dimensional truthmaker, semantics, solve the access problem in the epistemology of mathematics. Chapter \textbf{8} examines the interaction between Elohim's hyperintensional semantics and the axioms of epistemic set theory, large cardinal axioms, the Epistemic Church-Turing Thesis, the modal axioms governing the modal profile of $\Omega$-logic, Orey sentences such as the Generalized Continuum Hypothesis, and absolute decidability. These results yield inter alia the first hyperintensional Epistemic Church-Turing Thesis and hyperintensional epistemic set theories in the literature. Chapter \textbf{9} examines the modal and hyperintensional commitments of abstractionism, in particular necessitism, and epistemic hyperintensionality, epistemic utility theory, and the epistemology of abstraction. Elohim countenances a hyperintensional semantics for novel epistemic abstractionist modalities. Elohim suggests, too, that higher observational type theory can be applied to first-order abstraction principles in order to make first-order abstraction principles recursively enumerable, i.e. Turing machine computable, and that the truth of the first-order abstraction principle for two-dimensional hyperintensions is grounded in its being possibly recursively enumerable and the machine being physically implementable. Chapter \textbf{10} examines the philosophical significance of hyperintensional $\Omega$-logic in set theory and discusses the hyperintensionality of metamathematics. Chapter \textbf{11} provides a modal logic for rational intuition and provides a hyperintensional semantics. Chapter \textbf{12} avails of modal coalgebras to interpret the defining properties of indefinite extensibility, and avails of hyperintensional epistemic two-dimensional semantics in order to account for the interaction between interpretational and objective modalities and the truthmakers thereof. This yields the first hyperintensional category theory in the literature. Elohim invents a new mathematical trick in which first-order structures are treated as categories, and Vopenka's principle can be satisfied because of the elementary embeddings between the categories and generate Vopenka cardinals in the category of Set in category theory. Chapter \textbf{13} examines modal responses to the alethic paradoxes. Elohim provides a counter-example to epistemic closure for logical deduction. Chapter \textbf{14} examines, finally, the modal and hyperintensional semantics for the different types of intention and the relation of the latter to evidential decision theory. (shrink)

In this paper we present a general theory of normal forms, based on a categorial result for the free monoid construction. We shall use the theory mainly for proposictional modal logic, although it seems to have a wider range of applications. We shall formally represent normal forms as combinatorial objects, basically labelled trees and forests. This geometric conceptualization is implicit in and our approach will extend it to other cases and make it more direct: operations of a purely (...) geometric and combinatorial nature will be introduced in order to give a mathematical description of the basic logical/algebraic constructions .We begin by recalling the above-mentioned categorial construction: we need a careful inspection of it because in the various examples considered later we plan to deduce from it in a uniform way the normal forms and the description of finitely generated free algebras. This method always works whenever we can describe the category of algebras corresponding to the logic under consideration as a T-objects category. When this simple description seems not to be available, still the general theory might be of some interest, because a description of the category of algebras as a T-objects category plus equation is possible .The central part of the paper is more advanced and specific: we show how the general approach presented here can provide some insights even in the basic case of the modal system K. Section 4 contains a contribution to the theory of normal forms, namely the description of the uniform substitution. This result will enable us to give a duality theorem for the category of finitely generated free modal algebras and in Section 5 to provide a characterization of the collections of normal forms which happen to be normal forms for a logic, thus giving a description of the lattice of modal logics.Section 6 deals with some applications: we shall show how to use normal forms in order to prove for the modal system K the definability of higher-order propositional quantifiers and of the tense operator F .As to the prerequisites, the paper is almost self-contained. The reader is only assumed to have familiarity with standard techniques in algebraic logic ). Knowledge of the basic facts about adjoint functors is required too, see e.g. McLane or the appendix. (shrink)

Modal logic has been applied in many different areas, as reasoning about time, knowledge and belief, necessity and possibility, to mention only some examples. In the present paper, an attempt is made to use modal logic to account for the semantics of theoretical sentences in scientific language. Theoretical sentences have been studied extensively since the work of Ramsey and Carnap. The present attempt at a modal analysis is motivated by there being several intended interpretations of the theoretical terms once (...) these terms are introduced through the axioms of a theory. (shrink)

In Pantsar, an outline for an empirically feasible epistemological theory of arithmetic is presented. According to that theory, arithmetical knowledge is based on biological primitives but in the resulting empirical context develops an essentially a priori character. Such contextual a priori theory of arithmetical knowledge can explain two of the three characteristics that are usually associated with mathematical knowledge: that it appears to be a priori and objective. In this paper it is argued that (...) it can also explain the third one: why arithmetical knowledge appears to be necessary. A Kripkean analysis of necessity is used as an example to show that a proper analysis of the relevant possible worlds can explain arithmetical necessity in a sufficiently strong form. (shrink)