There has been much discussion of whether there could be objects A and B that are “individuatively vague” in the following way: object A and object B neither determinately stand in the relation of identity to one another, nor do they determinately fail to stand in this relation. If there are objects of this type, then we would have a genuine case of metaphysical vagueness, or “vagueness-in-the-world.” The possibility of vague objects in this sense strikes many as incoherent. (...) The possibility’s very description not only seems to talk of two objects but, much worse, it seems to point to a feature that distinguishes them: unlike object A, object B is not determinately identical to object A. This suspicion of incoherence is voiced in the famous arguments given against the possibility by Gareth Evans and Nathan Salmon. But the status of those arguments and others is uncertain. Here I present a new argument against vague objects — or more precisely, against the possibility of individuatively vague objects that satisfy an important and common additional condition that I will call “Democracy.” Since my argument turns on a connection between what is indeterminate and what is possible, I call it “the modal argument.”. (shrink)

Vague notions, such as ‘generally’, ‘rarely’, ‘often’, ‘almost always’, ‘a meaningful subset of a whole’, ‘most’, etc., occur often in ordinary language and in some branches of science. We introduce modal logical systems, with generalized operators, for the precise treatment of assertions involving some versions of such vague notions. We examine modal logics, constructed in a modular fashion, with generalized operators corresponding to some versions of ‘generally’ and ‘rarely’.

The prime purpose of this paper is, first, to restore to discourse-bound occasion sentences their rightful central place in semantics and secondly, taking these as the basic propositional elements in the logical analysis of language, to contribute to the development of an adequate logic of occasion sentences and a mathematical foundation for such a logic, thus preparing the ground for more adequate semantic, logical and mathematical foundations of the study of natural language. Some of the insights elaborated in this paper (...) have appeared in the literature over the past thirty years, and a number of new developments have resulted from them. The present paper aims atproviding an integrated conceptual basis for this new development in semantics. In Section 1 it is argued that the reduction by translation of occasion sentences to eternal sentences, as proposed by Russell and Quine, is semantically and thus logically inadequate. Natural language is a system of occasion sentences, eternal sentences being merely boundary cases. The logic hasfewer tasks than is standardly assumed, as it excludes semantic calculi, which depend crucially on information supplied by cognition and context and thus belong to cognitive psychology rather than to logic. For sentences to express a proposition and thus be interpretable and informative, they must first be properly anchored in context. A proposition has a truth value when it is, moreover, properly keyed in the world, i.e. is about a situation in the world. Section 2 deals with the logical properties of natural language. It argues that presuppositional phenomena require trivalence and presents the trivalent logic PPC3, with two kinds of falsity and two negations. It introduces the notion of -space for a sentence A as the basis of logical model theory, and the notion of P A /, functioning as a `private' subuniverse for A/A. The trivalent Kleene calculus is reinterpreted as a logical account of vagueness, rather than of presupposition. PPC3 and the Kleene calculus are refinements of standard bivalent logic and can be combined into one logical system. In Section 3 the adequacy of PPC3 as a truth-functional model of presupposition is considered more closely and given a Boolean foundation. In a noncompositional extended Boolean algebra, three operators are defined: 1a for the conjoined presuppositions of a, ã for the complement of a within 1a, and â for the complement of 1a within Boolean 1. The logical properties of this extended Boolean algebra are axiomatically defined and proved for all possible models. Proofs are provided of the consistency and the completeness of the system. Section 4 is a provisional exploration of the possibility of using the results obtained for a new discourse-dependent account of the logic of modalities in natural language. The overall result is a modified and refined logical and model-theoretic machinery, which takes into account both the discourse-dependency of natural language sentences and the necessity of selecting a key in the world before a truth value can be assigned. (shrink)

The prime purpose of this paper is, first, to restore to discourse-bound occasion sentences their rightful central place in semantics and secondly, taking these as the basic propositional elements in the logical analysis of language, to contribute to the development of an adequate logic of occasion sentences and a mathematical (Boolean) foundation for such a logic, thus preparing the ground for more adequate semantic, logical and mathematical foundations of the study of natural language. Some of the insights elaborated in this (...) paper have appeared in the literature over the past thirty years, and a number of new developments have resulted from them. The present paper aims at providing an integrated conceptual basis for this new development in semantics. In Section 1 it is argued that the reduction by translation of occasion sentences to eternal sentences, as proposed by Russell and Quine, is semantically and thus logically inadequate. Natural language is a system of occasion sentences, eternal sentences being merely boundary cases. The logic has fewer tasks than is standardly assumed, as it excludes semantic calculi, which depend crucially on information supplied by cognition and context and thus belong to cognitive psychology rather than to logic. For sentences to express a proposition and thus be interpretable and informative, they must first be properly anchored in context. A proposition has a truth value when it is, moreover, properly keyed in the world, i.e. is about a situation in the world. Section 2 deals with the logical properties of natural language. It argues that presuppositional phenomena require trivalence and presents the trivalent logic ${\rm PPC}_{3}$ , with two kinds of falsity and two negations. It introduces the notion of Σ-space for a sentence A (or / A /, the set of situations in which A is true) as the basis of logical model theory, and the notion of / ${\bf P}^{A}$ / (the Σ-space of the presuppositions of A), functioning as a 'private' subuniverse for / A /. The trivalent Kleene calculus is reinterpreted as a logical account of vagueness, rather than of presupposition. ${\rm PPC}_{3}$ and the Kleene calculus are refinements of standard bivalent logic and can be combined into one logical system. In Section 3 the adequacy of ${\rm PPC}_{3}$ as a truth-functional model of presupposition is considered more closely and given a Boolean foundation. In a noncompositional extended Boolean algebra, three operators are defined: $1_{a}$ for the conjoined presuppositions of a, ã for the complement of a within $1_{a}$ , and â for the complement of $1_{a}$ within Boolean 1. The logical properties of this extended Boolean algebra are axiomatically defined and proved for all possible models. Proofs are provided of the consistency and the completeness of the system. Section 4 is a provisional exploration of the possibility of using the results obtained for a new discourse-dependent account of the logic of modalities in natural language. The overall result is a modified and refined logical and model-theoretic machinery, which takes into account both the discourse-dependency of natural language sentences and the necessity of selecting a key in the world before a truth value can be assigned. (shrink)

How does vagueness interact with metaphysical modality and with restrictions of it, such as nomological modality? In particular, how do definiteness, necessity (understood as restricted in some way or not), and actuality interact? This paper proposes a model-theoretic framework for investigating the logic and semantics of that interaction. The framework is put forward in an ecumenical spirit: it is intended to be applicable to all theories of vagueness that express vagueness using a definiteness (or: determinacy) (...) operator. We will show how epistemicists, supervaluationists, and theorists of metaphysical vagueness like Barnes and Williams (2010) can interpret the framework.  We will also present a complete axiomatization of the logic we recommend to both epistemicists and local supervaluationists. . (shrink)

The aim of this article is to problematize, from a sociopolitical and psychoanalytic point of view, the current rise of the new rights, especially in Latin America. Although this extremist renaissance is loosely and indicatively referred to as fascism, we believe that, after careful analysis, today’s far-rights are not simple repetitions of the fascisms of the s. XX. It is about an unprecedented governmentality and ideology that, on the one hand, is not reduced to neoliberalism and, on the other hand, (...) surpasses the European-Anglo-Saxon alt-right and contemporary libertarianism. We give it the particular name of liber-fascism, to the extent that it brings a new mode of political subjectivation: the defender of himself. We divide the text into two sections. In the first, we discuss the sociopolitical particularities of liber-fascism: the emergence of a social ontology of the defender of himself that conceives of the capitalist market as an instance to be defended using false news, conspiracy theories and, of course, organized violence. In the second, we clarify the functioning of the liber-fascist unconscious by analyzing the peculiarity of its fantasy: it is an ideology that, in its relationship with others, uses violence no longer as a simple means, but as a vehicle for jouissance. (shrink)

Aristotle's modal syllogistic has been described as "incoherent," "a failure," "a realm of darkness." Even the gentler critics claim that it is inconsistent. I offer an interpretation according to which validity in the modal syllogistic is always obtained by substituting modal terms in the nonmodal syllogistic, and restricting the principles of modal conversion. In this paper I discuss the apodeictic syllogistic, showing that the restrictions I propose are powerful enough to do all the work Aristotle requires and, in fact, are (...) supported by a close analysis of Aristotle's text. The upshot of this is that there is for Aristotle no separate modal syllogistic. (shrink)

In this text, a variety of modal logics at the sentential, first-order, and second-order levels are developed with clarity, precision and philosophical insight. All of the S1-S5 modal logics of Lewis and Langford, among others, are constructed. A matrix, or many-valued semantics, for sentential modal logic is formalized, and an important result that no finite matrix can characterize any of the standard modal logics is proven. Exercises, some of which show independence results, help to develop logical skills. A separate sentential (...) modal logic of logical necessity in logical atomism is also constructed and shown to be complete and decidable. On the first-order level of the logic of logical necessity, the modal thesis of anti-essentialism is valid and every de re sentence is provably equivalent to a de dicto sentence. An elegant extension of the standard sentential modal logics into several first-order modal logics is developed. Both a first-order modal logic for possibilism containing actualism as a proper part as well as a separate modal logic for actualism alone are constructed for a variety of modal systems. Exercises on this level show the connections between modal laws and quantifier logic regarding generalization into, or out of, modal contexts and the conditions required for the necessity of identity and non-identity. Two types of second-order modal logics, one possibilist and the other actualist, are developed based on a distinction between existence-entailing concepts and concepts in general. The result is a deeper second-order analysis of possibilism and actualism as ontological frameworks. Exercises regarding second-order predicate quantifiers clarify the distinction between existence-entailing concepts and concepts in general. Modal Logic is ideally suited as a core text for graduate and undergraduate courses in modal logic, and as supplementary reading in courses on mathematical logic, formal ontology, and artificial intelligence. (shrink)

Inquiry into the metaphysics of essence tends to be pursued in a realist and model-theoretic spirit, in the sense that metaphysical vocabulary is used in a metalanguage to model truth conditions for the object-language use of essentialist vocabulary. This essay adapts recent developments in proof-theoretic semantics to provide a nominalist analysis for a variety of essentialist vocabularies. A metalanguage employing explanatory inferences is used to individuate introduction and elimination rules for atomic sentences. The object-language assertions of sentences concerning essences are (...) then interpreted as devices for marking off structural features of the explanatory inferences that, under a given interpretation, constitute the contents of the atoms of the language. On this proposal, object-language essentialist vocabulary is mentioned in a proof-theoretic metalanguage that uses a vocabulary of explanation. The result is a nominalist interpretation of essence as a modality, understood in the grammatical sense as a modification of the copula, and a view of metaphysical inquiry that is closely connected to the explanatory commitments present in first-order inquiry into things like sets, chemicals, and organisms. This result illustrates that some of the presuppositions that have animated analytic metaphysics over the last few decades can be profitably substituted with more practice-oriented conceptions of the forms of reasoning at work in different domains of human knowledge. (shrink)

Classical logic has proved inadequate in various areas of computer science, artificial intelligence, mathematics, philosopy and linguistics. This is an introduction to extensions of first-order logic, based on the principle that many-sorted logic (MSL) provides a unifying framework in which to place, for example, second-order logic, type theory, modal and dynamic logics and MSL itself. The aim is two fold: only one theorem-prover is needed; proofs of the metaproperties of the different existing calculi can be avoided by borrowing them from (...) MSL. To make the book accessible to readers from different disciplines, whilst maintaining precision, the author has supplied detailed step-by-step proofs, avoiding difficult arguments, and continually motivating the material with examples. Consequently this can be used as a reference, for self-teaching or for first-year graduate courses. (shrink)

In this paper I examine Grace A. de Laguna’s theory of universals in its historical context and in relation to contemporary debates in analytic metaphysics. I explain the central features of her theory, arguing that her theory should be classified as a form of immanent realism and as a powers ontology. I then show in what ways her theory affords a theory of modality in terms of potentialities and discuss some of its consequences along the way.

This article seeks to present a detailed textual analysis of Protagoras’ Great Speech in Plato's Protagoras. I will argue that the concept of ἀρετή as it appears in the Great Speech is whittled down to a vague notion of civic duty. In this respect, Protagoras is bringing himself in line with the democracy, but in doing so the ἀρετή he claims to teach loses much of its initial appeal, particularly in the eyes of his aristocratic clientele. Nevertheless, if thecontentof Protagoras’ (...) Great Speech overlooks the abilities required to rise to political prominence, theformmost assuredly does not. As one would expect from Plato's Protagoras, his speech is replete with just that oratorical prowess his students might expect to acquire from him. This, in turn, has a number of interesting and important implications in the broader context of theProtagoras, in particular regarding the contrast or conflict between long speeches and short-answer dialectic. Moreover, although it has long been noticed that Protagoras neglects rhetoric and personal pre-eminence in his account, as far as I know there has not been any serious attempt to analyse the stylistic aspects of this masterful speech. Accordingly, both this and my attempt to interpret it within the economy of the dialogue are original. (shrink)

Is what could have happened but never did as real as what did happen? What did happen, but isn't happening now, happened at another time. Analogously, one can say that what could have happened happens in another possible world. Whatever their views about the reality of such things as possible worlds, philosophers need to take this analogy seriously. Adriane Rini and Max Cresswell exhibit, in an easy step-by-step manner, the logical structure of temporal and modal discourse, and show that every (...) temporal construction has an exact parallel that requires a language that can refer to worlds, and vice versa. They make precise, in a way which can be articulated and tested, the claim that the parallel is at work behind even ordinary talk about time and modality. The book gives metaphysicians a sturdy framework for the investigation of time and modality - one that does not presuppose any particular metaphysical view. (shrink)

I argue against the Standard View of ignorance, according to which ignorance is defined as equivalent to lack of knowledge, that cases of environmental epistemic luck, though entailing lack of knowledge, do not necessarily entail ignorance. In support of my argument, I contend that in cases of environmental luck an agent retains what I call epistemic access to the relevant fact by successfully exercising her epistemic agency and that ignorance and non-ignorance, contrary to what the Standard View predicts, are not (...) modal in the sense that knowledge is. After responding to objections, I conclude by sketching an alternative account of ignorance centered on the notions of epistemic access and epistemic agency. (shrink)

Rough sets are used in numerous knowledge representation contexts and are then empowered with varied ontologies. These may be intrinsically associated with ideas of rationality under certain conditions. In recent papers, specific granular generalisations of graded and variable precision rough sets are investigated by the present author from the perspective of rationality of approximations (and the associated semantics of rationality in approximate reasoning). The studies are extended to ideal-based approximations (sometimes referred to as subsethood-based approximations). It is additionally shown that (...) co-granular or point-wise approximations defined by σ-ideals/filters (for an arbitrary relation σ) fit easily into the entire scheme. Concepts of the rationality of objects (vague or crisp) and their types are introduced and are shown to be applicable to most general rough sets by the present author. Surprising results on these are proved on these by her in this part of the research paper. The present paper is the first of a three part study on the topic. (shrink)

A peculiar feature of our species is that we settle what to believe, value, and do by reasoning through narratives. A narrative is adiachronic, information-rich story that contains persons, objects, and at least one event. When we reason through narrative, we usenarrative to settle what to do, to make predictions, to guide normative expectations, and to ground which reactive attitudes we think areappropriate in a situation. Narratives explain, justify, and provide understanding. Narratives play a ubiquitous role in human reasoning. Andyet, (...) narratives do not seem up to the task. Narratives are often unmoored representations (either because they are do not purport to referto the actual world, or because they are grossly oversimplified, or because are known to be literally false). Against this, I argue thatnarratives guide our reasoning by shaping our grasp of modal structure: what is possible, probable, plausible, permissible, required,relevant, desirable and good. Narratives are good guides to reasoning when they guide us to accurate judgments about modal space. Icall this the modal model of narrative. In this paper, I develop an account of how narratives function in reasoning, as well as an account ofwhen reasoning through narrative counts as good reasoning. (shrink)

Is what could have happened but never did as real as what did happen? What did happen, but isn't happening now, happened at another time. Analogously, one can say that what could have happened happens in another possible world. Whatever their views about the reality of such things as possible worlds, philosophers need to take this analogy seriously. Adriane Rini and Max Cresswell exhibit, in an easy step-by-step manner, the logical structure of temporal and modal discourse, and show that every (...) temporal construction has an exact parallel that requires a language that can refer to worlds, and vice versa. They make precise, in a way which can be articulated and tested, the claim that the parallel is at work behind even ordinary talk about time and modality. The book gives metaphysicians a sturdy framework for the investigation of time and modality - one that does not presuppose any particular metaphysical view. (shrink)

Imperialism seems to be deeply antithetical to democracy. Yet, at least one form of imperialism – what I call “hands-off imperialism" – seems to be perfectly compatible with the kind of self-governance commonly thought to be the hallmark of democracy. The solution to this puzzle is to recognize that democracy involves more than self-governance. Rather, it involves what I call self-rule. Self-rule is an example of what Philip Pettit has called a modally demanding value. Modally demanding values are, roughly, values (...) the instantiation of which depends not only on what actually happens, but on what would happen in certain non-actual circumstances. Self-rule is the modally demanding counterpart of self-governance, since it requires, not merely that the members of a state actually govern themselves, but that they would continue to do so across a range of non-actual situations. Moreover, the value of self-rule (and hence democracy) is not reducible to the value of self-governance. Understanding the modally demanding character of democracy allows us to appreciate what is democratically objectionable about occupation by a foreign power, even if there is no prospect of the foreign power intervening in the governance of the occupied state by its members. (shrink)

Recent research on algebraic models of _quasi-Nelson logic_ has brought new attention to a number of classes of algebras which result from enriching (subreducts of) Heyting algebras with a special modal operator, known in the literature as a _nucleus_. Among these various algebraic structures, for which we employ the umbrella term _intuitionistic modal algebras_, some have been studied since at least the 1970s, usually within the framework of topology and sheaf theory. Others may seem more exotic, for their primitive operations (...) arise from algebraic terms of the intuitionistic modal language which have not been previously considered. We shall for instance investigate the variety of _weak implicative semilattices_, whose members are (non-necessarily distributive) meet semilattices endowed with a nucleus and an implication operation which is not a relative pseudo-complement but satisfies the postulates of Celani and Jansana’s strict implication. For each of these new classes of algebras we establish a representation and a topological duality which generalize the known ones for Heyting algebras enriched with a nucleus. (shrink)

I address two related questions: first, what is the best theory of how objects have de re modal properties? Second, what is the best defence of essentialism given the variability of our modal intuitions? I critically discuss several theories of how objects have their de re modal properties and address the most threatening antiessentialist objection to essentialism: the variability of our modal intuitions. Drawing on linguistic treatments of vagueness and ambiguity, I show how essentialists can accommodate the variability of (...) modal intuitions while holding that objects have their modal properties independently of contexts. (shrink)

This paper presents a new theory of modal reasoning, i.e. reasoning about what may or may not be the case, and what must or must not be the case. It postulates that individuals construct models of the premises in which they make explicit only what is true. A conclusion is possible if it holds in at least one model, whereas it is necessary if it holds in all the models. The theory makes three predictions, which are corroborated experimentally. First, conclusions (...) correspond to the true, but not the false, components of possibilities. Second, there is a key interaction: it is easier to infer that a situation is possible as opposed to impossible, whereas it is easier to infer that a situation is not necessary as opposed to necessary. Third, individuals make systematic errors of omission and of commission. We contrast the theory with theories based on formal rules. (shrink)

There are many things, ideas, and entities that we encounter every single day that can be described as vague, that is, one cannot precisely classify them as members of a specific class of objects. Although many hold the opinion that vagueness is either a deficiency of spoken languages or something that exists merely because we do not have all relevant details, a third group of people assume that vagueness is something real. This simply means that objects, including living (...) beings, are vague. But if vagueness is a real thing, why do people ignore it when trying to explain a natural phenomenon, a syndrome, etc.? The reason is that people have a deep respect for pure, abstract objects with exact properties. But this has a negative effect on our understanding of our cosmos. Therefore, we investigate how vagueness really affects exact sciences and how the incorporation of vagueness will improve our understanding of our world. (shrink)

This chapter offers an overview of the phenomenological approach to delusions, emphasizing what Karl Jaspers called the "true delusions" of schizophrenia. Phenomenological psychopathology focuses on the experience of delusions and the delusional world. Several features of this approach are surveyed, including emphasis on formal qualities of subjective life and questioning of standard assumptions about delusions as erroneous belief. The altered modalities of world-oriented and self-oriented experience that precede and ground delusions in schizophrenia, especially the experiences of revelation that Klaus Conrad (...) termed the outer and inner apophany, are then discussed. The chapter first considers the famous "delusional mood", then the role of ipseity-disturbance. In both cases it is explained how delusions can develop out of these distinctive alterations of perception and feeling. The classic question of the understandability or comprehensibility of schizophrenic delusion, together with the related issues of wish-fulfillment and rationalizing motives are then considered. The chapter addresses the crucial but neglected issue of the felt reality-status of delusions or the delusional world, discussing derealization, "double bookkeeping", and "double exposure". The chapter concludes by discussing delusions typically found in paranoid and affective psychoses, and monothematic delusions found in certain organic conditions. (shrink)

In this paper we show how recent concepts from Dynamic Logic, and in particular from Dynamic Epistemic logic, can be used to model and interpret quantum behavior. Our main thesis is that all the non-classical properties of quantum systems are explainable in terms of the non-classical flow of quantum information. We give a logical analysis of quantum measurements (formalized using modal operators) as triggers for quantum information flow, and we compare them with other logical operators previously used to model various (...) forms of classical information flow: the “test” operator from Dynamic Logic, the “announcement” operator from Dynamic Epistemic Logic and the “revision” operator from Belief Revision theory. The main points stressed in our investigation are the following: (1) The perspective and the techniques of “logical dynamics” are useful for understanding quantum information flow. (2) Quantum mechanics does not require any modification of the classical laws of “static” propositional logic, but only a non-classical dynamics of information. (3) The main such non-classical feature is that, in a quantum world, all information-gathering actions have some ontic side-effects. (4) This ontic impact can affect in its turn the flow of information, leading to non-classical epistemic side-effects (e.g. a type of non-monotonicity) and to states of “objectively imperfect information”. (5) Moreover, the ontic impact is non-local: an information-gathering action on one part of a quantum system can have ontic side-effects on other, far-away parts of the system. (shrink)

Standards and norms for reasoning function, in part, to manage epistemic risk. Properly used, modal qualifiers like presumably have a role in systematically managing epistemic risk by flagging and tracking type-specific epistemic merits and risks of the claims they modify. Yet, argumentation-theoretic accounts of presumption often define it in terms of modalities of other kinds, thereby failing to recognize the unique risk profile of each. This paper offers a stipulative account of presumption, inspired by Ullmann-Margalit, as an inferentially generated modal (...) qualifier, “presumably, p,” distinguishing it from other, particularly epistemic modalities, e.g., standing commitments, assumptions, assertions, suppositions, hypotheses, and defeasible claims. By avoiding the tranching of inferential instruments of qualitatively different bona fides and risk profiles, this account provides a more accurate risk-rating system that better manages epistemic risk in inference, as well as contributing to the normative theory of the operation of presumption in reasoning and argument. (shrink)

We give a definition of bisimulation for conditional modalities interpreted on selection functions and prove the correspondence between bisimilarity and modal equivalence, generalizing the Hennessy–Milner Theorem to a wide class of conditional operators. We further investigate the operators and semantics to which these results apply. First, we show how to derive a solid notion of bisimulation for conditional belief, behaving as desired both on plausibility models and on evidence models. These novel definitions of bisimulations are exploited in a series of (...) undefinability results. Second, we treat relativized common knowledge, underlining how the same results still hold for a different modality in a different semantics. Third, we show the flexibility of the approach by generalizing it to multi-agent systems, encompassing the case of multi-agent plausibility models. (shrink)

Many attempts have been made in recent months to throw light on the problem of vagueness. That perfect precision is an ideal not to be attained by any language seems clear. But the obvious fact is that words and sentences in our languages are not so precise as we should like to have them, and we are naturally concerned with finding some sort of device by which vagueness can, in the first place, be detected and measured, and, in (...) the second place, eliminated or reduced to a minimum. I shall not be concerned in what follows with these various special attempts to meet the problem. My task is the somewhat more general one of showing that there are other factors contributing to vagueness, one of which is of particular significance when we leave the realm of ostensively defined symbols and begin to concern ourselves with suppositional symbols, constructs and hypotheses. (shrink)

I present here a modal extension of T called KTLM which is, by several measures, the simplest modal extension of T yet presented. Its axiom uses only one sentence letter and has a modal depth of 2. Furthermore, KTLM can be realized as the logical union of two logics KM and KTL which each have the finite model property (f.m.p.), and so themselves are complete. Each of these two component logics has independent interest as well.

Any realist interpretation of quantum theory must grapple with the measurement problem and the status of state-vector collapse. In a no-collapse approach, measurement is typically modeled as a dynamical process involving decoherence. We describe how the minimal modal interpretation closes a gap in this dynamical description, leading to a complete and consistent resolution to the measurement problem and an effective form of state collapse. Our interpretation also provides insight into the indivisible nature of measurement—the fact that you can't stop a (...) measurement part-way through and uncover the underlying 'ontic' dynamics of the system in question. Having discussed the hidden dynamics of a system's ontic state during measurement, we turn to more general forms of open-system dynamics and explore the extent to which the details of the underlying ontic behavior of a system can be described. We construct a space of ontic trajectories and describe obstructions to defining a probability measure on this space. (shrink)

A major criticism of David Lewis’ counterfactual theory of causation is that it allows too many things to count as causes, especially since Lewis allows, in addition to events, absences to be causes as well. Peter Menzies has advanced this concern under the title “the problem of profligate causation.” In this paper, I argue that the problem of profligate causation provides resources for exposing a tension between Lewis’ acceptance of absence causation and his modal realism. The result is a different (...) problem of profligate causation—one that attacks the internal consistency of Lewisian metaphysics rather than employing common sense judgments or intuitions that conflict with Lewis’ extensive list of causes. (shrink)

This paper deals with the exceptions-tolerance property of generic sentences with indefinite singular and bare plural subjects (IS and BP generics, respectively) and with the way this property is connected to some well-known observations about felicity differences between the two types of generics (e.g. Lawler's 1973, Madrigals are popular vs. #A madrigal is popular). I show that whereas both IS and BP generics tolerate exceptional and contextually irrelevant individuals and situations in a strikingly similar way, which indicates the existence of (...) a basically equivalent tolerance mechanism, there is also a difference between them, unnoticed so far, which concerns the degree to which the properties of the legitimate exceptions can be characterized in advance. Following claims in Greenberg (2003), I argue that both this newly observed difference as well as the traditional felicity differences result from an underlying contrast in the type of ‘non-accidentalness’ expressed by the two types of generic sentences, and more formally, in the accessibility relations that their generic quantifier (Gen) is compatible with. To capture the new difference in tolerance of exceptions, I develop an improved version of the exceptions-tolerance mechanism for generic sentences suggested in Kadmon & Landman (1993), namely, a restriction on the set of individuals and situations quantified by Gen, which is partially vague to two different degrees using supervaluationist methods. The different degrees of vagueness in this restriction are shown to be systematically dependent on the two types of accessibility relations that IS and BP generics are compatible with, which are redefined as precise and vague restrictions on the generic quantification over worlds. (shrink)

The author analyses the problem of the communication from the epistemological point of view, noting that the interest to the theme is obviously determined by the enormous ambiguity and by the disciplinary vagueness of the communication's notion itself. It is argued that it is the philosophical conceptualization of the communication that allows in a certain sense to «save» philosophy itself. The author notes that the philosophical studies of communication as if return the relevance to the classical philosophical problems: to (...) the (communicative) sphere, (communicative) time, (social) causality, (collective) subject and object, filling them with the meaningful characteristics and testing their concepts by the experience of the functioning of real society and communication. He concludes that the epistemological content of the concept of communication is comes together with several aspects of human cognition. The first aspect has to do with the dimensions for defining the adequacy for determination of the statement made by the Other (i.e. the other participant), given that the content of the Other's consciousness is unavailable. The second aspect is related to the principle of a double purpose of any communication: on the one hand, integration and mutual understanding and, on the other, informational description of the subject of the message. The third aspect is that communication is based on the most important epistemological distinction between knowledge and ignorance, i.e. on the predominance of any information to one participant of the communication and of its uncertainty to the other participant, and that such a situation actually conditions the formation of communication systems, as well as of a wide variety of forms of sociality. The author also addresses the problem of whether contemporary media make communication at all possible since they decrease the impact that the secrecy of the Other's consciousness has on communication by triggering a communicative act. (shrink)

Consent transforms an otherwise illegitimate act into a legitimate one. To be valid, however, it must be adequately informed. The legal requirement is vague and provides little assistance in predicting when it will be satisfied. This is particularly so when a patient consents to a procedure and the physician subsequently varies one of the components of that procedure. Using three legal judgments and one General Medical Council decision as a springboard, I have explored the concept of a medical procedure within (...) the context of consent and developed a theoretical model to elucidate a more predictable and consistent informational requirement. (shrink)

G.W.F. Hegel argues that a philosophy of history should engender comprehension of evil in the world. And yet some commentators have charged his philosophy with transcending mere explication by justifying the existence of these evils. In defense of his words, Hegel famously characterizes evil as a modal mismatch; namely, as the incompatibility between what is given and what ought to be the case. Unfortunately, some readers of Hegel’s grand narrative either continue to struggle with or overlook this fine distinction. Against (...) such readings, I organize my paper into three sections that speak directly to these concerns. In §1, against the concern that Hegel’s view of the “actual world” justifies suffering, it is shown that his philosophy does not endorse the merely extant world, which is a whole world apart from the actual world. In §2, I articulate the premises of Hegel’s Doppelsatz to argue that the famous slogan is not, as some commentators take it, an endorsement of “things as they are.” And in §3, I expose a category error that mistakes an epistemological claim made by Hegel about contingency as a metaphysical assertion in support of evil. Ultimately, I argue that Hegel views evil as neither actual nor necessary nor justified. (shrink)

This introduction to the basic ideas of structural proof theory contains a thorough discussion and comparison of various types of formalization of first-order logic. Examples are given of several areas of application, namely: the metamathematics of pure first-order logic (intuitionistic as well as classical); the theory of logic programming; category theory; modal logic; linear logic; first-order arithmetic and second-order logic. In each case the aim is to illustrate the methods in relatively simple situations and then apply them elsewhere in much (...) more complex settings. There are numerous exercises throughout the text. In general, the only prerequisite is a standard course in first-order logic, making the book ideal for graduate students and beginning researchers in mathematical logic, theoretical computer science and artificial intelligence. For the new edition, many sections have been rewritten to improve clarity, new sections have been added on cut elimination, and solutions to selected exercises have been included. (shrink)

[Edited from Conclusion section:] We have looked at various challenging issues to do with getting connectionism to cope with high-level cognitive activities such a reasoning and natural language understanding. The issues are to do with various facets of generalization that are not commonly noted. We have been concerned in particular with the special forms these issues take in the arena of propositional attitude processing. The main problems we have looked at are: (1) The need to construct explicit representations of generalizations, (...) not just generalize correctly to individual cases; (2) The need to be able to match two or more complex short-term information structures, to enable rapid generalization from recent examples rather than from long-term memories; (3) The need to represent and reason with anomalous combinations of concepts; (4) The need to perform embedded reasoning. This presents special problems for systems using non-concatenative representations (as in mainstream connectionist approaches). We also touched on vague quantification in attitude report complements. Neither this topic nor that of analogies between short-term structures (point 2) has been adequately addressed in the symbolic framework, let alone in connectionism. -/- The opportunities and problems covered are put forward as things worth being optimistic about or pessimistic about, respectively. They are not put forward as decisive arguments for or against connectionism. The hope is that this chapter contributes to a greater understanding of the connectionist/symbolist gap by presenting some unusual issues and by throwing new light on some well known ones. (shrink)