We present a computational analysis of de re, de dicto, and de se belief and knowledge reports. Our analysis solves a problem first observed by Hector-Neri Castañeda, namely, that the simple rule -/- `(A knows that P) implies P' -/- apparently does not hold if P contains a quasi-indexical. We present a single rule, in the context of a knowledge-representation and reasoning system, that holds for all P, including those containing quasi-indexicals. In so doing, we explore the difference between reasoning (...) in a public communication language and in a knowledge-representation language, we demonstrate the importance of representing proper names explicitly, and we provide support for the necessity of considering sentences in the context of extended discourse (for example, written narrative) in order to fully capture certain features of their semantics. (shrink)

In this entry I present one of the most hotly debated issues in contemporary analytic philosophy regarding the nature of fictional entities and the motivations that might be adduced for and against positing them into our ontology. The entry is divided in two parts. In the first part I offer an overview of the main accounts of the metaphysics of fictional entities according to three standard realist views, fictional Meinongianism, fictional possibilism and fictional creationism. In the second part I describe (...) two main kinds of arguments for or against positing fictional entities into our ontology. The first kind is traditionally inspired by the linguistic data coming from our talk about fictional characters. The second kind is more recent and it builds on genuine ontological considerations. (shrink)

This paper has three main sections. The first section provides a general characterisation of presentism, eternalism and growing blockism. It presents a pair of core, defining claims that jointly capture each of these three views. This makes clear the respects in which the different views agree, and the respects in which they disagree, about the nature of time. The second section takes these characterisations and considers whether we really do have three distinct views, or whether defenders of these views are (...) somehow talking past one another when they claim to disagree. The third section looks at the key objections to each view and considers some of the replies that can be made to those objections. The paper concludes by offering some thoughts about how future research might help us resolve the debate between defenders of these three views. (shrink)

According to Crane’s schematicity thesis (ST) about intentional objects, intentionalia have no particular metaphysical nature qua thought-of entities; moreover, the real metaphysical nature of intentionalia is various, insofar as it is settled independently of the fact that intentionalia are targets of one’s thought. As I will point out, ST has the ontological consequence that the intentionalia that really belong to the general inventory of what there is, the overall domain, are those that fall under a good metaphysical kind, i.e., a (...) kind such that its members figure (for independent reasons) in such an inventory. Negatively put, if there are no things of a certain metaphysical kind, thoughts about things of that kind are not really committed to such things. Pace Crane, however, this does not mean that the intentionalia that are really there are only those that exist. For existence, qua first-order property, is no metaphysical kind. Thus, there may really be intentionalia that do not exist, provided that they belong to good metaphysical kinds. (shrink)

In this paper, I will defend the claim that there are three existence properties: the second-order property of being instantiated, a substantive first-order property (or better a group of such properties) and a formal, hence universal, first-order property. I will first try to show what these properties are and why we need all of them for ontological purposes. Moreover, I will try to show why a Meinong-like option that positively endorses both the former and the latter first-order property is the (...) correct view in ontology. Finally, I will add some methodological remarks as to why this debate has to be articulated from the point of view of reality, i.e., by speaking of properties, rather than from the point of view of language, i.e., by speaking of predicates (for such properties). (shrink)

O propósito deste trabalho é fornecer uma resposta a duas questões fundamentais: 1) pode uma lógica não alética ser uma lógica meinongiana? E consequentemente 2) pode uma lógica não alética ser uma lógica adequada a uma teoria meinongiana dos objetos? Usando os resultados de da Costa (1989) e da Costa & Marconi (1986) e além disso de da Costa (1986 e 1993), proponho uma lógica minimal não alética de primeira ordem com identidade e o símblo " de Hilbert (da Costa (...) et al. 1992) que podem colocar em um espírito meinongiano os aspectos mais relevantes da lógica meinongiana subajcente à teoria dos objetos de Meinong. Esta é apenas uma primeira abordagem minha, para dar conta de reflexões complexas, mas também interessante como o pensamento de Meinong. Além disso, dando uma resposta positiva a 1) e 2) indico um modo plausível que pode evitar ambas as difíceis abordagens e a tentativa de recusar a teoria dos objetos de modo a não comprometer a lógica padrão e algumas de suas leis. Minha abordagem mostra que a teoria de Meinong pode ser uma ontologia válida, porque há uma lógica adequada e não banal subjacente a ela. DOI:10.5007/1808-1711.2010v14n1p99. (shrink)

Deliberate contextual vocabulary acquisition (CVA) is a reader’s ability to figure out a (not the) meaning for an unknown word from its “context”, without external sources of help such as dictionaries or people. The appropriate context for such CVA is the “belief-revised integration” of the reader’s prior knowledge with the reader’s “internalization” of the text. We discuss unwarranted assumptions behind some classic objections to CVA, and present and defend a computational theory of CVA that we have adapted to a new (...) classroom curriculum designed to help students use CVA to improve their reading comprehension. (shrink)

In this reply to James H. Fetzer’s “Minds and Machines: Limits to Simulations of Thought and Action”, I argue that computationalism should not be the view that (human) cognition is computation, but that it should be the view that cognition (simpliciter) is computable. It follows that computationalism can be true even if (human) cognition is not the result of computations in the brain. I also argue that, if semiotic systems are systems that interpret signs, then both humans and computers are (...) semiotic systems. Finally, I suggest that minds can be considered as virtual machines implemented in certain semiotic systems, primarily the brain, but also AI computers. In doing so, I take issue with Fetzer’s arguments to the contrary. (shrink)

This book is both an introduction to and a research work on Meinongianism. “Meinongianism” is taken here, in accordance with the common philosophical jargon, as a general label for a set of theories of existence – probably the most basic notion of ontology. As an introduction, the book provides the first comprehensive survey and guide to Meinongianism and non-standard theories of existence in all their main forms. As a research work, the book exposes and develops the most up-to-date Meinongian theory (...) (called modal Meinongianism), applies it to specific fields, and discusses its open problems. Part I of the book provides a historical introduction to, and critical discussion of, the dominant philosophical view of existence: the “Kantian-Fregean-Quinean” perspective. Part II is the full-fledged introduction to the Meinongian theories of existence as a real property of individuals: after starting with the so-called naïve Meinongian conception and its problems, it provides a self-contained presentation of the main neo-Meinongian proposals, and a detailed discussion of their strengths and weaknesses. Part III develops a specific neo-Meinongian theory of existence employing a model-theoretic semantic framework. It discusses its application to the ontology and semantics of fictional objects, and its open problems. The methodology of the book follows the most recent trends in analytic ontology. In particular, the meta-ontological point of view is largely privileged. (shrink)

We investigate the form of mathematical structuralism that acknowledges the existence of structures and their distinctive structural elements. This form of structuralism has been subject to criticisms recently, and our view is that the problems raised are resolved by proper, mathematics-free theoretical foundations. Starting with an axiomatic theory of abstract objects, we identify a mathematical structure as an abstract object encoding the truths of a mathematical theory. From such foundations, we derive consequences that address the main questions and issues that (...) have arisen. Namely, elements of different structures are different. A structure and its elements ontologically depend on each other. There are no haecceities and each element of a structure must be discernible within the theory. These consequences are not developed piecemeal but rather follow from our definitions of basic structuralist concepts. (shrink)

This essay presents a philosophical and computational theory of the representation of de re, de dicto, nested, and quasi-indexical belief reports expressed in natural language. The propositional Semantic Network Processing System (SNePS) is used for representing and reasoning about these reports. In particular, quasi-indicators (indexical expressions occurring in intentional contexts and representing uses of indicators by another speaker) pose problems for natural-language representation and reasoning systems, because--unlike pure indicators--they cannot be replaced by coreferential NPs without changing the meaning of the (...) embedding sentence. Therefore, the referent of the quasi-indicator must be represented in such a way that no invalid coreferential claims are entailed. The importance of quasi-indicators is discussed, and it is shown that all four of the above categories of belief reports can be handled by a single representational technique using belief spaces containing intensional entities. Inference rules and belief-revision techniques for the system are also examined. (shrink)

A computer can come to understand natural language the same way Helen Keller did: by using “syntactic semantics”—a theory of how syntax can suffice for semantics, i.e., how semantics for natural language can be provided by means of computational symbol manipulation. This essay considers real-life approximations of Chinese Rooms, focusing on Helen Keller’s experiences growing up deaf and blind, locked in a sort of Chinese Room yet learning how to communicate with the outside world. Using the SNePS computational knowledge-representation system, (...) the essay analyzes Keller’s belief that learning that “everything has a name” was the key to her success, enabling her to “partition” her mental concepts into mental representations of: words, objects, and the naming relations between them. It next looks at Herbert Terrace’s theory of naming, which is akin to Keller’s, and which only humans are supposed to be capable of. The essay suggests that computers at least, and perhaps non-human primates, are also capable of this kind of naming. (shrink)

In this book, Zalta attempts to lay the axiomatic foundations of metaphysics by developing and applying a (formal) theory of abstract objects. The cornerstones include a principle which presents precise conditions under which there are abstract objects and a principle which says when apparently distinct such objects are in fact identical. The principles are constructed out of a basic set of primitive notions, which are identified at the end of the Introduction, just before the theorizing begins. The main reason for (...) producing a theory which defines a logical space of abstract objects is that it may have a great deal of explanatory power. It is hoped that the data explained by means of the theory will be of interest to pure and applied metaphysicians, logicians and linguists, and pure and applied epistemologists. (shrink)

In (1991), Meinwald initiated a major change of direction in the study of Plato’s Parmenides and the Third Man Argument. On her conception of the Parmenides , Plato’s language systematically distinguishes two types or kinds of predication, namely, predications of the kind ‘x is F pros ta alla’ and ‘x is F pros heauto’. Intuitively speaking, the former is the common, everyday variety of predication, which holds when x is any object (perceptible object or Form) and F is a property (...) which x exemplifies or instantiates in the traditional sense. The latter is a special mode of predication which holds when x is a Form and F is a property which is, in some sense, part of the nature of that Form. Meinwald (1991, p. 75, footnote 18) traces the discovery of this distinction in Plato’s work to Frede (1967), who marks the distinction between pros allo and kath’ hauto predications by placing subscripts on the copula ‘is’. (shrink)

Though my ultimate concern is with issues in epistemology and metaphysics, let me phrase the central question I will pursue in terms evocative of philosophy of religion: What are the implications of our logic-in particular, of Cantor and G6del-for the possibility of omniscience?

The proper treatment of computationalism, as the thesis that cognition is computable, is presented and defended. Some arguments of James H. Fetzer against computationalism are examined and found wanting, and his positive theory of minds as semiotic systems is shown to be consistent with computationalism. An objection is raised to an argument of Selmer Bringsjord against one strand of computationalism, namely, that Turing-Test± passing artifacts are persons, it is argued that, whether or not this objection holds, such artifacts will inevitably (...) be persons. (shrink)

I advocate a theory of syntactic semantics as a way of understanding how computers can think (and how the Chinese-Room-Argument objection to the Turing Test can be overcome): (1) Semantics, considered as the study of relations between symbols and meanings, can be turned into syntax – a study of relations among symbols (including meanings) – and hence syntax (i.e., symbol manipulation) can suffice for the semantical enterprise (contra Searle). (2) Semantics, considered as the process of understanding one domain (by modeling (...) it) in terms of another, can be viewed recursively: The base case of semantic understanding –understanding a domain in terms of itself – is syntactic understanding. (3) An internal (or narrow ), first-person point of view makes an external (or wide ), third-person point of view otiose for purposes of understanding cognition. (shrink)

This essay continues my investigation of `syntactic semantics': the theory that, pace Searle's Chinese-Room Argument, syntax does suffice for semantics (in particular, for the semantics needed for a computational cognitive theory of natural-language understanding). Here, I argue that syntactic semantics (which is internal and first-person) is what has been called a conceptual-role semantics: The meaning of any expression is the role that it plays in the complete system of expressions. Such a `narrow', conceptual-role semantics is the appropriate sort of semantics (...) to account (from an `internal', or first-person perspective) for how a cognitive agent understands language. Some have argued for the primacy of external, or `wide', semantics, while others have argued for a two-factor analysis. But, although two factors can be specified–-one internal and first-person, the other only specifiable in an external, third-person way–-only the internal, first-person one is needed for understanding how someone understands. A truth-conditional semantics can still be provided, but only from a third-person perspective. (shrink)

Some 55 years after the publication of Russell's seminal ‘On Denoting’, Quine adopted the theory of definite descriptions presented therein to formulate his perspicuous lingua franca for the sciences. This paper illustrates how, in so doing, Quine's lingua franca inherited an old antinomy at the core of Russell's theory of definite descriptions, specifically, the lack of congruency between notation and metaphysical commitments when the variable assumes the role of fundamental singular reference. In this context, the paper contends that the phrase (...) ‘to be is purely and simply to be the value of the variable’ is far from the straightforward solution Quine initially envisioned for his lingua franca. Additionally, it argues that it is unlikely that an attempt to account for a determinate object theory, such as those propounded by Russell and Quine, can prove successful when grounded in a referential theory of quantificational logic where the variable, seen as a simple range of values, holds fundamental singular referent‐position. The paper concludes by suggesting that Meinong's object theory could resolve the problem of the variable, albeit at the cost of potentially undesirable ontological and logical commitments. Alternatively, Kit Fine's recent work on other antinomies in the variable may provide a promising approach to exploring how to salvage the variable as a formal foundation for ontology. (shrink)

In this article, I explore the problems of ficta ‘generation’ and ‘properties’ in light of the philosophies of Alexius Meinong and Roman Ingarden. Comparing Ingarden and the historical Meinong is not a novel idea. By contrast, comparing Ingarden and a phenomenological Meinong has not, to my knowledge, yet been explored. Here, I rely on Alberto Voltolini’s ‘phenomenological conception of außerseiende entities’. I devise Ingarden’s phenomenological ontology to account for the problems of ascription and generation that cripple Meinong’s account. In short, (...) I argue that Ingarden’s account is better suited to accommodate ficta’s generation and properties in a way that does not complicate our approach to fiction. (shrink)

This paper aims to introduce Meinongian Abstractionism (MA), i.e. a view on the metaphysics of truthmaking and modality. This approach is based on the notion of objectives—one of the key elements of Alexius Meinong’s Theory of Objects. In the light of it, worlds are interpreted in terms of sets of subsistent and non-subsistent objectives. This—along with Meinong’s characterization of objectives—provides a ground for possible as well as impossible worlds. One of the consequences of Meinongain Abstractionism is a reformulation of the (...) relation of truthmaking in modal terms. Importantly, this reformulation avoids the problem of too-coarse grained analysis of truthmakers. This makes MA a metaphysically–oriented supporter of the so-called ‘hyperintensional revolution.’. (shrink)

According to Millianism, the meaning of a name is exhausted by its referent. According to anti-realism about fictional entities, there are no such entities. If there are no fictional entities, how can we explain the apparent meaningfulness of fictional names? Our best theory of fiction, Walton’s theory of make-believe, makes the same assumptions but lacks the theoretical resources to answer the question. In this paper, I propose a pragmatic solution in terms of two main dimensions of meaning, a subjective, psychological (...) dimension and an intersubjective, public dimension. The psychological dimension builds on the notion of mental files; the public dimension builds on Stalnaker’s notion of common ground. The account is coherent with two main theoretical principles, parsimony and uniformity. Furthermore, it satisfies three explanatory conditions posed by the intentionality of our thought and discourse about fiction, object-directedness, counterfictional imagining and intersubjective identification. (shrink)

A paradox about sets of properties is presented. The paradox, which invokes an impredicatively defined property, is formalized in a free third-order logic with lambda-abstraction, through a classically proof-theoretically valid deduction of a contradiction from a single premise to the effect that every property has a unit set. Something like a model is offered to establish that the premise is, although classically inconsistent, nevertheless consistent, so that the paradox discredits the logic employed. A resolution through the ramified theory of types (...) is considered. Finally, a general scheme that generates a family of analogous paradoxes and a generally applicable resolution are proposed. (shrink)

Fictionalism about a kind of disputed object is often motivated by the fact that the view interprets discourse about those objects literally without an ontological commitment to them. This paper argues that this motivation is inadequate because some viable alternatives to fictionalism have similar attractions. Meinongianism—the view that there are true statements about non-existent objects—is one such view. Meinongianism bears significant similarity to fictionalism, so intuitive doubts about its viability are difficult to sustain for fictionalists. Moreover, Meinongianism avoids some of (...) fictionalism’s weaknesses, thus it is even preferable to fictionalism in some respects. (shrink)

2020 update of the entry "Properties".

It is usually taken for granted that a necessary condition for knowing that P is the truth of P. It may therefore be claimed that if we assume that we gain some kind of knowledge through fiction (let us call it fictional knowledge) of P*, then P* should be true—in at least a certain sense. My hypothesis is that this assumption grounds the different ways adopted by philosophers for attributing truth-conditions to fictional sentences. My claim in this work is that (...) fictional sentences do not have truth-values and truth-conditions, but I want to maintain that we gain some kind of knowledge through fiction: to this aim, I will characterize the objective content of fictional sentences not in terms of truth-conditions (which are usually described by appealing to rules of the language or rules of interpretation of language independent of the actual users), but in dispositional terms and I will define a necessary condition for fictional knowledge accordingly. (shrink)

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

The aim of this paper is to explore the possibility that, at least, some metaphysical debates are ‘metalinguistic negotiations’. I will take the dispute between the dominant approaches of realism and the anti-realism ones about the ontological status of scientific models as a case-study. I will argue that such a debate may be better understood as a disagreement, at bottom normatively, motivated, insofar as a normative and non-factual question may be involved in it: how the relevant piece of language ought (...) to be used. Even though I will generally assess the prospects for a broadly deflationist approach, I shall outline a sense in which the dispute can be recast as ‘minimally substantive’. (shrink)

ABSTRACTI propose a different account of fictional objects from the ones already present in the literature. According to my account, fictional objects are culturally created abstract objects dependent for their existence on the pretence attitude adopted by a group of people towards a single fictional content. My work is divided into three parts: in the first one, I present how fictional objects come into existence according to my proposal; in the second part, I illustrate how the existence of fictional objects (...) so conceived may be ontically indeterminate; in the last part, I consider what happens when vague existence and indeterminate identity are claimed within fictional texts. (shrink)

This essay describes computational semantic networks for a philosophical audience and surveys several approaches to semantic-network semantics. In particular, propositional semantic networks are discussed; it is argued that only a fully intensional, Meinongian semantics is appropriate for them; and several Meinongian systems are presented.

Przedmiotem artykułu jest status ontologiczny światów możliwych oraz niemożliwych. Zgodnie z jedną ze współczesnych wersji meinongianizmu, o ile świat aktualny jest przedmiotem istniejącym, o tyle światy czysto możliwe oraz niemożliwe uznawane są za przedmioty nieistniejące. Zwolennicy tego podejścia twierdzą ponadto, że światom nieaktualnym nie przysługuje żaden inny rodzaj istnienia.Celem artykułu jest wskazanie na problematyczne konsekwencje wspomnianego stanowiska oraz zarysowanie poglądu alternatywnego, który oparty jest na pluralizmie ontologicznym, tj. na poglądzie uznającym wielość rodzajów istnienia.

In my thesis, I aim to develop a systematic and philosophically coherent thesis of ultimate reality for Ibn Arabi. In this pursuit, I adopt the style of analytic philosophy, seeking to employ and utilise some of its methods and theories. The philosophical aspects of Ibn Arabi’s doctrine are in dire need of conceptual clarification and systematic analysis with a closer focus on argumentation. The analytic tradition will prove most helpful in this regard. In my thesis, I begin by tracing Ibn (...) Arabi’s related views and concepts as they are dispersed throughout his writings. I then clarify, sharpen and, in many cases, develop these views and concepts into fully constructed forms. Finally, I weave the developed concepts and views into a systematic thesis or set of sub-theses. Where necessary, I provide my own arguments and concepts to help substantiate and strengthen the structure of Ibn Arabi’s thesis. I propose that Ibn Arabi’s various, and sometimes apparently inconsistent, views are best presented in terms of three main concepts: the concept of ultimate reality as existence, which has long been known as Ibn Arabi’s thesis of the oneness of existence ; the concept of ultimate reality as the Divine Self ; and the concept of ultimate reality as God. The three concepts neither represent different ultimate realities nor different perspectives of the same ultimate reality. Instead, they represent the same ultimate reality but each one has its own unique scope and encompassment. The three concepts are aimed at encompassing Ibn Arabi’s various views and concepts of ultimate reality in a consistent and systematic manner. (shrink)

This third paper locates the synthetic neurorobotics research reviewed in the second paper in terms of themes introduced in the first paper. It begins with biological non-reductionism as understood by Searle. It emphasizes the role of synthetic neurorobotics studies in accessing the dynamic structure essential to consciousness with a focus on system criticality and self, develops a distinction between simulated and formal consciousness based on this emphasis, reviews Tani and colleagues' work in light of this distinction, and ends by forecasting (...) the increasing importance of synthetic neurorobotics studies for cognitive science and philosophy of mind going forward, finally in regards to most- and myth-consciousness. (shrink)

In this paper, we compare two theories, modal Meinongianism and object theory, with respect to several issues that have been discussed recently in the literature. In particular, we raise some objections for MM, undermine some of the objections that its defenders raise for OT, and we point out some virtues of the latter with respect to the former.

This paper serves as a kind of field guide to certain passages in the literature which bear upon the foundational theory of abstract objects. The foundational theory assimilates ideas from key philosophers in both the analytical and phenomenological traditions. I explain how my foundational theory of objects serves as a common ground where analytic and phenomenological concerns meet. I try to establish how the theory offers a logic that systematizes a well-known phenomenological kind of entity, and I try to show (...) the various ways the theory systematizes the ideas of many analytic philosophers. The ideas of Plato, Leibniz, Frege, Russell, Goedel and even Kripke become connected through those of Brentano, Meinong, Husserl, and Mally. -/- The field guide will not only document the passages in which the distinction between two kinds of predication originates, but also document the other surprising, and often unrelated, contexts where the distinction reappears in the work of others. It will also document ways in which the theory can be used to represent precisely the ideas of the philosophers mentioned above. The resulting guide will bring together the works of many different authors, including some clearly within the analytic tradition, some clearly within the phenomenological tradition, and some who straddle the divide. (shrink)

There is a list of desiderata that any good metaphysics of fictional entities should be able to fulfill. These desiderata are: 1) the nonexistence of fictional entities; 2) the causal inefficacy of suchentities;3)the incompleteness of such entities;4)the created character of such entities; 5) the actual possession by ficta of the narrated properties; 6) the unrevisable ascription to ficta of such properties; and 7) the necessary possession by ficta of such properties. (Im)possibilist metaphysics uncontroversially satisfy 1) and 2); Neo-Meinongian metaphysics satisfy (...) 1), 2), 3), 5), 6), and 7); artefactualist or creationist metaphysics uncontroversially satisfy 1), 2), 3), and 4). Another metaphysics is needed in order to satisfy all such desiderata. In this chapter Idevelop such a metaphysics, claiming that a Syncretistic metaphysics that combines Neo-Meinongianism with Artefactualism achieves this purpose. According to Syncretism, ficta are hybrid entities individuated in terms of both a certain makebelieve narrative process and the set of properties that one such narration mobilizes. Toward the end of the chapter I consider some possible criticisms to this approach: its non-intuitiveness; ficta’s unnecessary proliferation; and troubles with creationism of any sort. (shrink)

In this paper we reply to arguments of Kroon (“Characterization and Existence in Modal Meinongianism”. Grazer Philosophische Studien 86, 23–34) to the effect that Modal Meinongianism cannot do justice to Meinongian claims such as that the golden mountain is golden, and that it does not exist.

The arguments of the dialetheists for the rejection of the traditional law of noncontradiction are not yet conclusive. The reason is that the arguments that they have developed against this law uniformly fail to consider the logic of encoding as an analytic method that can resolve apparent contradictions. In this paper, we use Priest [1995] and [1987] as sample texts to illustrate this claim. In [1995], Priest examines certain crucial problems in the history of philosophy from the point of view (...) of someone without a prejudice in favor of classical logic. For each of these problems, the logic of encoding offers an alternative explanation of the phenomena---this alternative is not considered when Priest describes what options there are in classical logic for analyzing the problem at hand. (shrink)

The modal object calculus is the system of logic which houses the (proper) axiomatic theory of abstract objects. The calculus has some rather interesting features in and of itself, independent of the proper theory. The most sophisticated, type-theoretic incarnation of the calculus can be used to analyze the intensional contexts of natural language and so constitutes an intensional logic. However, the simpler second-order version of the calculus couches a theory of fine-grained properties, relations and propositions and serves as a framework (...) for defining situations, possible worlds, stories, and fictional characters, among other things. In the present paper, we focus on the second-order calculus. The second-order modal object calculus is so-called to distinguish it from the second-order modal predicate calculus. Though the differences are slight, the extra expressive power of the object calculus significantly enhances its ability to resolve logical and philosophical concepts and problems. (shrink)

Are there nonexistent objects, i.e., objects that do not exist? Some examples often cited are: Zeus, Pegasus, Sherlock Holmes, Vulcan (the hypothetical planet postulated by the 19th century astronomer Le Verrier), the perpetual motion machine, the golden mountain, the fountain of youth, the round square, etc. Some important philosophers have thought that the very concept of a nonexistent object is contradictory (Hume) or logically ill-formed (Kant, Frege), while others (Leibniz, Meinong, the Russell of Principles of Mathematics) have embraced it wholeheartedly. (...) This entry is an examination of the many questions which arise in connection with the view that there are nonexistent objects. The following are particularly salient: What reasons are there (if any) for thinking that there are nonexistent objects? If there are nonexistent objects, then what kind of objects are they? How can they be characterized? Is it possible to provide a consistent theory of nonexistent objects? What is the explanatory force of a consistent theory of nonexistent objects (if such a thing is possible)? (shrink)

In this paper, the author shows how one can independently prove, within the theory of abstract objects, some of the most significant claims, hypotheses, and background assumptions found in Kripke's logical and philosophical work. Moreover, many of the semantic features of theory of abstract objects are consistent with Kripke's views — the successful representation, in the system, of the truth conditions and entailments of philosophically puzzling sentences of natural language validates certain Kripkean semantic claims about natural language.

In the debate about the nature and identity of possible worlds, philosophers have neglected the parallel questions about the nature and identity of moments of time. These are not questions about the structure of time in general, but rather about the internal structure of each individual time. Times and worlds share the following structural similarities: both are maximal with respect to propositions (at every world and time, either p or p is true, for every p); both are consistent; both are (...) closed (every modal consequence of a proposition true at a world is also true at that world, and every tense-theoretic consequence of a proposition true at a time is also true at that time); just as there is a unique actual world, there is a unique present moment; and just as a proposition is necessarily true iff true at all worlds, a proposition is eternally true iff true at all times. In this paper, I show that a simple extension of my theory of worlds yields a theory of times in which the above structural similarities between the two are consequences. (shrink)

Some recently-proposed counterexamples to the traditional definition of essential property do not require a separate logic of essence. Instead, the examples can be analysed in terms of the logic and theory of abstract objects. This theory distinguishes between abstract and ordinary objects, and provides a general analysis of the essential properties of both kinds of object. The claim ‘x has F necessarily’ becomes ambiguous in the case of abstract objects, and in the case of ordinary objects there are various ways (...) to make the definition of ‘F is essential to x’ more fine-grained. Consequently, the traditional definition of essential property for abstract objects in terms of modal notions is not correct, and for ordinary objects the relationship between essential properties and modality, once properly understood, addresses the counterexample. (shrink)

Anselm's Ontological Argument fails, but not for any of the various reasons commonly adduced. In particular, its failure has nothing to do with violating deep Kantian principles by treating ‘exists’ as a predicate or making reference to ‘Meinongian’ entities. Its one fatal flaw, so far from being metaphysically deep, is in fact logically shallow, deriving from a subtle scope ambiguity in Anselm's key phrase. If we avoid this ambiguity, and the indeterminacy of reference to which it gives rise, then his (...) argument is blocked even if his supposed Meinongian extravagances are permitted. Moreover it is blocked in a way which is straightforward and compelling (by contrast with the Kantian objections), and which generalizes easily to other versions of the Ontological Argument. A significant moral follows. Fear of Anselm's argument has been hugely influential in motivating ontological fastidiousness and widespread reluctance to countenance talk of potentially non-existing entities. But if this paper is correct, then the Ontological Argument cannot properly provide any such motivation. Some of the most influential contributions to ontology, from Kant to Russell and beyond, rest on a mistake. (shrink)