Discussion of atomistic and monistic theses about abstract reality.

During the past few decades, a radical shift has occurred in how philosophers conceive of the relation between science and philosophy. A great number of analytic philosophers have adopted what is commonly called a ‘naturalistic’ approach, arguing that their inquiries ought to be in some sense continuous with science. Where early analytic philosophers often relied on a sharp distinction between science and philosophy—the former an empirical discipline concerned with fact, the latter an a priori discipline concerned with meaning—philosophers today largely (...) follow Willard Van Orman Quine (1908-2000) in his seminal rejection of this distinction. -/- This book offers a comprehensive study of Quine’s naturalism. Building on Quine’s published corpus as well as thousands of unpublished letters, notes, lectures, papers, proposals, and annotations from the Quine archives, this book aims to reconstruct both the nature (chapters 2-4) and the development (chapter 5-7) of his naturalism. As such, this book aims to contribute to the rapidly developing historiography of analytic philosophy, and to provide a better, historically informed, understanding of what is philosophically at stake in the contemporary naturalistic turn. (shrink)

W. V. Quine’s first philosophical monograph, Word and Object, is widely recognized as one of the most influential books of twentieth century philosophy. Notes, letters, and draft manuscripts at the Quine Archives, however, reveal that Quine was already working on a philosophical book in the early 1940s; a project entitled Sign and Object. In this paper, I examine these and other unpublished documents and show that Sign and Object sheds new light on the evolution of Quine’s ideas. Where “Two Dogmas (...) of Empiricism” is usually considered to be a turning point in Quine’s development, this paper redefines the place of ‘Two Dogmas’ in his oeuvre. Not only does Quine’s book project reveal that his views were already fairly naturalistic in the early 1940s ; Sign and Object also unearths the steps Quine had to take in maturing his perspective; steps that will be traced in the second half of this paper. (shrink)

The view, in Quine, that all there are are pure sets is presented and endorsed.

This book is an exploration and defense of the coherence of classical theism’s doctrine of divine aseity in the face of the challenge posed by Platonism with respect to abstract objects. A synoptic work in analytic philosophy of religion, the book engages discussions in philosophy of mathematics, philosophy of language, metaphysics, and metaontology. It addresses absolute creationism, non-Platonic realism, fictionalism, neutralism, and alternative logics and semantics, among other topics. The book offers a helpful taxonomy of the wide range of options (...) available to the classical theist for dealing with the challenge of Platonism. It probes in detail the diverse views on the reality of abstract objects and their compatibility with classical theism. It contains a most thorough discussion, rooted in careful exegesis, of the biblical and patristic basis of the doctrine of divine aseity. Finally, it challenges the influential Quinean metaontological theses concerning the way in which we make ontological commitments. (shrink)

Ontology played a very large role in Quine’s philosophy and was one of his major preoccupations from the early 30’s to the end of his life. His work on ontology provided a basic framework for most of the discussions of ontology in analytic philosophy in the second half of the Twentieth Century. There are three main themes (and several sub-themes) that Quine developed in his work. The first is ontological commitment: What are the existential commitments of a theory? The second (...) is ontological reduction: How can an ontology be reduced to (or substituted by) another? And what is the most economical ontology that can be obtained for certain given purposes? The third is criteria of identity: When are entities of some kind (sets, properties, material objects, propositions, meanings, etc.) the same or different? In this paper I discuss Quine’s development of these three themes and some of the problems that were aised in connection with his work. (shrink)

The paper seeks to answer two new questions about truth and scientific change: What lessons does the phenomenon of scientific change teach us about the nature of truth? What light do recent developments in the theory of truth, incorporating these lessons, throw on problems arising from the prevalence of scientific change, specifically, the problem of pessimistic meta-induction?

In response to comments on my book, Being Realistic about Reasons, by Justin Clarke-Doane, David Enoch and Tristram McPherson, and Gideon Rosen, I try to clarify my domain-based view of ontology, my understanding of the epistemology of normative judgments, and my interpretation of the phenomenon of supervenience.

This article presents a novel argument against a common principle of parsimony in philosophy. First, it identifies a widely employed principle of positive ontological parsimony, according to which we should, ceteris paribus, prefer smaller ontologies to larger ontologies. Next, it shows how this principle is used as part of a strategy by which to argue for antirealist positions in many subfields of philosophy: the ockhamistic antirealist strategy. Third, it argues that this principle commits its adherents to an implausible epistemological thesis—the (...) Eroding Ontology Thesis—according to which evidence for the existence of some entity is at least prima facie evidence against the existence of all other entities. Antirealists might decide to adopt a related position, ontological conservatism, according to which we should simply resist changing our ontology, but the article shows that it is independently unjustified. Therefore, it concludes, philosophers have good reason to cease employing one very common antirealist strategy. (shrink)

Don Marquis’s “future-like-ours” argument against the moral permissibility of abortion is widely considered the strongest anti-abortion argument in the philosophical literature. In this paper, I address the issue of whether the argument relies upon controversial metaphysical premises. It is widely thought that future-like-ours argument indeed relies upon controversial metaphysics, in that it must reject the psychological theory of personal identity. I argue that that thought is mistaken—the future-like-ours argument does not depend upon the rejection of such a theory. I suggest, (...) however, that given a widely-accepted view about contraception and abstinence, the argument is committed to contentious metaphysics after all, as it relies upon a highly controversial assumption about mereology. This commitment is not only relevant for those who are inclined to endorse the argument but reject the mereological view in question, but in addition entails dialectical and epistemological liabilities for the argument, which on some views will be fatal to the argument’s overall success. (shrink)

This essay defends the neo-Quinean approach to ontology against the criticisms of two neo-Carnapians, Huw Price and Amie Thomasson.

The main aim of the paper is to reconstruct and analyse two methodological approaches to the problem of universals, presented in Bocheński’s papers “Powszechniki jako treści cech w filozofii św. Tomasza z Akwinu” and “The Problem of Universals.” It is argued that, although these approaches are rather different from historical and methodological points of view, they are still based on the same ontological ground, viz. on immanent realism. The article provides a detailed analysis and comparison of the respective views. Justification (...) is provided for the claim that Bocheński was an immanent realist and some of Bocheński’s detailed solutions are highlighted that may be of particular importance for further debate over the problem of universals. A couple of minor critical comments concerning some of Bocheński’s analyses are presented at the end of the paper. (shrink)

This essay considers implications of formal mereologies and ontologies for medical metaphysics. Edward Fried’s extensional mereological account of the human body is taken as representative of a prominent strand in analytic metaphysics that has close affinities with medical positivism. I show why such accounts fail. First, I consider how Fried attempts to make sense of the medical case of Barney Clark, the first recipient of an artificial heart, and show that his analytic metaphysical categories do not have the right kind (...) of fit with the case. A proper medical metaphysic should involve a richer two way dialogue with medicine, and it should not just “apply” formal accounts worked out in other settings. Second, I argue that any effort to account for real wholes with extensional mereological sums requires all sorts of ad hoc, supplementary mechanisms that do the real work, and the full repertoire of these mechanisms involves inconsistencies and semantic shifts. Finally, I consider an alternative strand of work on non-extensional whole/part relations that is closer to medicine and that can deepen reflection on some core problems in bioethics, for example, associated with the determination of death when an organism ceases to function as a whole. In addition to the utility such formal ontologies have for addressing traditional problems such as the determination of death, philosophers of medicine should appreciate the increasingly influential role such formal tools are playing in the development of data system ontologies. Assumptions integral to these ontologies have far reaching implications for the way future research and practice in medicine will be conducted, and much greater critical reflection is needed on the full range of issues associated with the development and use of such medical ontologies. (shrink)

In sections 1 through 5, I develop in detail what I call the standard theory of worlds and propositions, and I discuss a number of purported objections. The theory consists of five theses. The first two theses, presented in section 1, assert that the propositions form a Boolean algebra with respect to implication, and that the algebra is complete, respectively. In section 2, I introduce the notion of logical space: it is a field of sets that represents the propositional structure (...) and whose space consists of all and only the worlds. The next three theses, presented in sections 3, 4, and 5, respectively, guarantee the existence of logical space, and further constrain its structure. The third thesis asserts that the set of propositions true at any world is maximal consistent; the fourth thesis that any two worlds are separated by a proposition; the fifth thesis that only one proposition is false at every world. In sections 6 through 10, I turn to the problem of reduction. In sections 6 and 7, I show how the standard theory can be used to support either a reduction of worlds to propositions or a reduction of propositions to worlds. A number of proposition-based theories are developed in section 6, and compared with Adams's world-story theory. A world-based theory is developed in section?, and Stalnaker's account of the matter is discussed. Before passing judgment on the proposition based and world-based theories, I ask in sections 8 and 9 whether both worlds and propositions might be reduced to something else. In section 8, I consider reductions to linguistic entities; in section 9, reductions to unfounded sets. After rejecting the possibility of eliminating both worlds and propositions, I return in section 10 to the possibility of eliminating one in favor of the other. I conclude, somewhat tentatively, that neither worlds nor propositions should be reduced one to the other, that both worlds and propositions should be taken as basic to our ontology. (shrink)

Universalism (the thesis that distinct objects always compose a further object) has come under much scrutiny in recent years. What has been largely ignored is its role in the metaphysics of classes. Not only does universalism provide ways to deal with classes in a metaphysically pleasing fashion, its success on these grounds has been offered as a motivation for believing it. This paper argues that such treatments of classes can be achieved without universalism, examining theories from Goodman and Quine, Armstrong (...) and Lewis. In the case of each theory, universalism is drafted in to ensure that there are enough material objects to play a particular role. I argue that, for each theory, there's a better theory that ditches universalism and instead uses an alternative principle of composition demanding that the unrestricted composition of entities other than material objects (respectively: regions, states of affairs and singletons) play that role instead. I conclude that (1) non-universalists can consider accepting such theories of classes and (2) we should ignore any alleged motivation for universalism on the basis of dealing with classes. (shrink)

"Philosophical discussion of the notion of existence, or being, has centered on two main problems which have not always been very clearly distinguished. First, there is the problem of what we are to say about the existence of fictitious objects, such as centaurs, dragons, and Pegasus; second, there is the problem of what we are t o say about the existence of abstract objects, such as qualities, relations, and numbers. Both problems have tempted philosophers to say that there are inferior (...) sorts of existence a s well as the ordinary straightforward sort, and they therefore often suggest that we use the word "being" to cover both kinds but restrict "existence" to "being" of the common, non-fictitious, non-abstract sort. (Sometimes the term "reality" is proposed for "existence" or for "being.") T he problems of fiction and abstraction are different, how ever, for there are both real and fictitious abstractions. For example, the integer between two and four is real, but the integer between two and three is fictitious. On the other hand, there are both concrete and abstract fictions; for example, the winged horse of Bellerophon and the integer between two and three. Accordingly, philosophers have often dealt with the two problems in quite different ways and perhaps ought to do so. While these are the two main problems, there are others, f or example, that of what we are to say of the being of objects which have not yet begun, or have now ceased, to exist. The history of this subject, moreover, has been tangled with theological issues, to which it will be necessary to refer at certain points.". (shrink)

Le nominalisme est « le refus d'admettre toute entité autre qu'indivi-duelle ». II doit, pour justifier la simplicité de son ontologie, proposer une théorie de laconnaissance et une théorie sémantique qui ne présupposent ni l'une ni l'autre l'existence réelle des univer-saux. Certaines des voies qui s'ouvrent à cette entreprise délicate ont été systématiquement explorées vers la fin du Moyen Age et il y a tout à parier que, malgré les ruptures épistémologiques, les révolutions scientifiques et autres changements d'epistémè, les nominalistes (...) contemporains pourraient encore profiter de quelque façon de l'immense travail théorique accompli par leurs prédécesseurs médiévaux. C'est dans cet esprit que je voudrais procéder à une reconstruction sommaire de la théorie sémantique avancée au début du quatorzième siècle par le Fran-ciscain Guillaume d'Occam. Je ne m'engagerai pas dans une comparaison détaillée entre Occam et les auteurs contemporains, mais j'essaierai de présenter sans en trahir l'esprit la sémantique occa-miste de manière à en faire apparaître la pertinence pour les débats actuels. II serait possible, me semble-t-il, d'aller encore plus loin dans cette voie en mettant à profit les techniques formelles récentes pour axiomatiser la théorie d'Occam. Pour l'instant cependant, je me limiterai à une présentation plutôt informelle. (shrink)

The dispute between nominalists and Platonic realists has been with us for a long time — long enough to have assumed many forms. I don't want to rehearse the history of these various debates, or even to look at the matter from a historical point of view. But I would like to begin by distinguishing two quite different skirmishes in the general battle, one of which is new, and one of which is very old. We begin with the new one, (...) which is the clearest. (shrink)

I consider the well-known criticism of Quine's characterization of first-order logical truth that it expands the class of logical truths beyond what is sanctioned by the model-theoretic account. Briefly, I argue that at best the criticism is shallow and can be answered with slight alterations in Quine's account. At worse the criticism is defective because, in part, it is based on a misrepresentation of Quine. This serves not only to clarify Quine's position, but also to crystallize what is and what (...) is not at issue in choosing the model-theoretic account of first-order logical truth over one in terms of substitutions. I conclude by highlighting the need for justifying the belief that the definition of first-order logical truth in terms of models is superior to its definition in terms of substitutions. (shrink)

This article attempts to motivate a new approach to anti-realism (or nominalism) in the philosophy of mathematics. I will explore the strongest challenges to anti-realism, based on sympathetic interpretations of our intuitions that appear to support realism. I will argue that the current anti-realistic philosophies have not yet met these challenges, and that is why they cannot convince realists. Then, I will introduce a research project for a new, truly naturalistic, and completely scientific approach to philosophy of mathematics. It belongs (...) to anti-realism, but can meet those challenges and can perhaps convince some realists, at least those who are also naturalists. (shrink)

Philosophers have tried to explain how science finds the truth by using new developments in logic to study scientific language and inference. R. G. Collingwood argued that only a logic of problems could take context into account. He was ignored, but the need to reconcile secure meanings with changes in context and meanings was seen by Karl Popper, W. v. O. Quine, and Mario Bunge. Jagdish Hattiangadi uses problems to reconcile the need for security with that for growth. But he (...) mistakenly insists that all problems are mere contradictions and artificially separates rigid from flexible aspects of meanings. In order to resolve the conflict we must (1) replace the quest for rigid terms with techniques for improvement, (2) use plausible arguments to uncover confused meanings, (3) use frameworks to choose problems and to regulate meanings, and (4) employ a bootstrap approach that uses frameworks to improve meanings and refined meanings to improve frameworks. (shrink)

In “Empiricism, Semantics, and Ontology” Carnap drew his famous distinction between ‘internal’ and ‘external’ questions of existence, pronouncing the former meaningful and the latter meaningless. In The Significance of Philosophical Scepticism, Barry Stroud understands Carnap to be applying the verification criterion of meaningfulness in order to refute Cartesian skepticism. I suggest that Stroud misrepresents both Carnap’s aim and method. Carnap was responding to critics who suggested that his willingness to quantify over abstract entities in his work in semantics violated his (...) commitment to empiricism. He rejected that criticism as presupposing a super-scientific standpoint from which constraints on the admissible domain of entities of science could be delivered. Carnap wanted to insulate science from the imposition of frrst-philosophical metaphysical prejudice, not to defuse scepticism by appeal to verificationism. (shrink)

Though largely unnoticed, in “Two Dogmas” Quine himself invokes a distinction: a distinction between logical and analytic truths. Unlike analytic statements equating ‘bachelor’ with ‘unmarried man’, strictly logical tautologies relating two word-tokens of the same word-type, e.g., ‘bachelor’ and ‘bachelor’ are true merely in virtue of basic phonological form, putatively an exclusively non-semantic function of perceptual categorization or brute stimulus behavior. Yet natural language phonemic categorization is not entirely free of interpretive semantic considerations. “Phonemic reductionism” in both its linguistic and (...) behavioral, Newbury Park, CA, Sage Publications, 164–167) guise is false. The semantic basis of phonological equivalence, however, has repercussions vis-à-vis Quine’s critique of analyticity. A consistent rejection of meaning-based equivalencies eliminates not only analyticity, but imposes a form of phonological eliminativism too. Phonological eliminativism is the reductio result of applying Quinean meaning skepticism to the phonological typing of natural language. But unlike analyticity, phonology is presumably not subject to philosophical dismissal. The semantic basis of natural language phonology serves to neutralize Quine’s argument against analyticity: without the semantics of meaning, more than just synonymy is lost; basic phonology must also be forfeited. Let’s begin with the fact that even Quine has to admit that it is possible for two tokens of the same orthographic type to be synonymous, for that much is presupposed by his own account of logical truth. Paul Boghossian. (shrink)

Let “explanationism” be the view that ontology is fundamentally an explanatory enterprise. What it does is “on a par” with natural science, as Quine put it. Carnap appears to offer a “lighter weight” alternative in “Empiricism, Semantics, and Ontology”: ontology is concerned with semantics and language choice. This paper argues that Carnap’s account of the internal/external distinction is of less use than Carnap suggests for diagnosis of disputes in ontology. But he largely agrees with Quine about explanationism. I propose that (...) explanationism is an attractive metametaphysical position between “heavy weight” and “light weight” views. Its method is abductive inference, which is broader than “light weight” methods. Since it is “on a par” with natural science, ontology contributes nothing beyond the claim that what there is, is what our best theories say there is. Hence, it is not “heavy weight”. (shrink)

This paper defends two claims about the criterion of commitment of W.V.O Quine. The first claim is that the criterion can be made extensional. The second is that a proper formulation becomes an analytic truth. We spend a few preliminary sections clarifying our intended notion of ontological commitment. We will not go very far in our investigation of the criterion if we do not distinguish the things a theory postulates, what its adherents, or anybody else, believe in, and which of (...) these entities we have compelling reasons to accept. A look at [Quine 1953] shows that the criterion concerned the postulation of entities by theories, but it is often misread as an attempt to say something about either or. The core of the paper is an exposition of two formulations of the criterion. I first state a schema improving on that of [Scheffler and Chomsky 1959]. The second formulation is a single principle and construes commitment as a relation between theories and predicates: ontological commitment to the entities that satisfy a given predicate. Both criteria are extensional and are formulated for constructional systems, in the sense of [Carnap 1928] and [Goodman 1951], rather than for theories construed as interpreted sets of sentences. This solves a problem raised by [Halvorson 2019]. Their analyticity is substantiated by showing that their most controversial consequences are instances of Tarski’s Convention. (shrink)

Metaphysicians now typically distinguish between a theory’s ontology and its ideology. But besides a few cursory efforts, no one has explained the role of ideology in theory choice. In this paper I develop a framework for discussing how differing approaches to ideology impact metaphysical disputes. I first provide an initial characterization of ideology and develop two contrasting types of criteria used to evaluate its quality. In using externalist criteria, we judge the quality of a theory’s ideology by its relation to (...) external features of the world. In contrast, in using internalist criteria, we judge the quality of a theory’s ideology by features internal to the theory and the theorizer, e.g. the intelligibility of the terminology employed. I then argue for an unrestricted application of externalist criteria, what I call maximal realism. According to maximal realism, we ought to apply externalist criteria to the entirety of a theory’s ideology—to not only predicates but also to quantifiers and logical operators. I defend maximal realism from what I take to be the best objection to it: that the view leads to bad questions. As part of my defense, I argue that those who would restrict their application of externalist criteria either adopt an unjustified partition of ideology or reject seemingly benign questions. Finally, I apply my discussion of ideology to two extant metaphysical disputes. (shrink)

As analytic philosophy is becoming increasingly aware of and interested in its own history, the study of that field is broadening to include, not just its earliest beginnings, but also the mid-twentieth century. One of the towering figures of this epoch is W.V. Quine (1908-2000), champion of naturalism in philosophy of science, pioneer of mathematical logic, trying to unite an austerely physicalist theory of the world with the truths of mathematics, psychology, and linguistics. Quine's posthumous papers, notes, and drafts revealing (...) the development of his views in the forties have recently begun to be published, as well as careful philosophical studies of, for instance, the evolution of his key doctrine that mathematical and logical truth are continuous with, not divorced from, the truths of natural science. But one central text has remained unexplored: Quine's Portuguese-language book on logic, his 'farewell for now' to the discipline as he embarked on an assignment in the Navy in WWII. Anglophone philosophers have neglected this book because they could not read it. Jointly with colleagues, I have completed the first full English translation of this book. In this accompanying paper I draw out the main philosophical contributions Quine made in the book, placing them in their historical context and relating them to Quine's overall philosophical development during the period. Besides significant developments in the evolution of Quine's views on meaning and analyticity, I argue, this book is also driven by Quine's indebtedness to Russell and Whitehead, Tarski, and Frege, and contains crucial developments in his thinking on philosophy of logic and ontology. This includes early versions of some arguments from 'On What There Is', four-dimensionalism, and virtual set theory. (shrink)

W. V. Quine is arguably the intellectual father of contemporary naturalism, the idea that there is no distinctively philosophical perspective on reality. Yet, even though Quine has always been a science-minded philosopher, he did not adopt a fully naturalistic perspective until the early 1950s. In this paper, I reconstruct the genesis of Quine’s ideas on the relation between science and philosophy. Scrutinizing his unpublished papers and notebooks, I examine Quine’s development in the first decades of his career. After identifying three (...) commitments supporting his naturalism—viz. empiricism, holism, and realism—I piece together the evolution of Quine’s position by examining the origins of these commitments one by one, showing how his early views gradually evolved into the mature naturalistic position that would have such an enormous impact on post-war analytic philosophy. (shrink)

A central metaphilosophical project seeks to evaluate the reliability of the types of evidence that figure in philosophical arguments and, relatedly, the justificatory status of relying on those types of evidence. Traditionally, metaphilosophers have approached this project via an analysis of intuition. This article argues that the category picked out by “intuition” is both too broad and too heterogeneous to serve as the appropriate target for metaphilosophical inquiry. Intuition is a gerrymandered and disjunctive kind, undeserving of the widespread attention it (...) receives in the literature. Instead, metaphilosophers should examine more finely grained mental states. Three promising strategies for parsing intuitions more finely are proposed: by their causal origins, by their context of employment, and by the exoticism of their content. This more narrow focus may significantly alter the dialectic in three prominent metaphilosophical arguments: the argument from calibration, the argument from self-defeat, and the argument from intuitional sensitivity. (shrink)

Though largely unnoticed, in "Two Dogmas" Quine himself invokes a distinction: a distinction between logical and analytic truths. Unlike analytic statements equating 'bachelor' with 'unmarried man', strictly logical tautologies relating two word-tokens of the same word-type, e.g., 'bachelor' and 'bachelor' are true merely in virtue of basic phonological form, putatively an exclusively non-semantic function of perceptual categorization or brute stimulus behavior. Yet natural language phonemic categorization is not entirely free of interpretive semantic considerations. "Phonemic reductionism" in both its linguistic and (...) behavioral, Newbury Park, CA, Sage Publications, 164-167) guise is false. The semantic basis of phonological equivalence, however, has repercussions vis-à-vis Quine's critique of analyticity. A consistent rejection of meaning-based equivalencies eliminates not only analyticity, but imposes a form of phonological eliminativism too. Phonological eliminativism is the reductio result of applying Quinean meaning skepticism to the phonological typing of natural language. But unlike analyticity, phonology is presumably not subject to philosophical dismissal. The semantic basis of natural language phonology serves to neutralize Quine's argument against analyticity: without the semantics of meaning, more than just synonymy is lost; basic phonology must also be forfeited. (shrink)

Intensional contexts are typically characterised by an apparent failure of either (A) the principle of the inter-substitution of co-referring terms salva veritate, or (B) existential generalisation. The difficulties which are seen to occur do so in contexts involving either modality or the propositional attitudes. In this paper attempts are made to determine whether or not Scheffler’s inscriptional analysis can provide a viable means of accounting for the problems which are thought to occur in intensional contexts. Somewhat unexpectedly, little effort has (...) been made in the past to address this issue. In this paper it is shown that Scheffler’s theory may be employed to account for the difficulties mentioned above, though further work needs to be done to show precisely how his analysis may be adapted so as to handle modal statements. Popular objections to Scheffler’s inscriptionalism are also addressed, particularly in the light of his theory being used to account for the problems of intensionality. It is found that, with certain qualifications, the aforesaid objections do not show Scheffler’s theory to be an unviable means of accounting for the intensionality problems. (shrink)

The paper is concerned with the way in which “ontology” and “realism” are to be interpreted and applied so as to give us a deeper philosophical understanding of mathematical theories and practice. Rather than argue for or against some particular realistic position, I shall be concerned with possible coherent positions, their strengths and weaknesses. I shall also discuss related but different aspects of these problems. The terms in the title are the common thread that connects the various sections.

William Tait's standing in the philosophy of mathematics hardly needs to be argued for; for this reason the appearance of this collection is especially welcome. As noted in his Preface, the essays in this book ‘span the years 1981–2002’. The years given are evidently those of publication. One essay was not previously published in its present form, but it is a reworking of papers published during that period. The Introduction, one appendix, and some notes are new. Many of the essays (...) will be familiar to the readers of this journal; indeed two first appeared here.It should be no surprise to those who know Tait's work that this is a very rich collection, with contributions on a wide variety of issues, both systematic and historical. That poses a problem for a reviewer, because a serious discussion of even all the major issues would be beyond the scope of a review.Before the essays in this collection, Tait's publications were almost all in mathematical logic, especially proof theory. He was a leading actor in the work on the revised Hilbert program stimulated after the war by Georg Kreisel, Kurt Schütte, and Gaisi Takeuti. Tait thus has an experience in mathematical research that is rare among those whose careers have been institutionally in philosophy. In the 1970s Tait became disillusioned with the proof-theoretic program on which he had worked. However, he draws on that background in several of these essays, and he has continued to work on mathematical questions. In particular, the set-theoretic project reflected in essay 6 is as much mathematical as philosophical.It is not easy to characterize Tait's philosophical viewpoint briefly. Both the title of the book and some of its content mark him as a rationalist. His hero in the earlier history …. (shrink)

Abstract This paper aims to analyse Karl Popper's conception of ?three worlds?, and especially the problem of world 3?the world of objective knowledge. Firstly, I try to explain Popper's turn to ontological questions which I link to his antipsychologism and to issues raised by the development of logic after World War II. I then consider Popper's concept of the autonomy of world 3 and his attempt to introduce world 3 as a world of knowledge without a knowing subject. I conclude (...) that Popper did not succeed in unifying his central idea of autonomy of knowledge with the requirement of the creative role of the critical subject carrying out the evolution of knowledge. I see the core of this contradiction especially in his co?existing ideas of the timeless existence of world 3 and the elimination of the subject from it. The attempt to desubjectivize the realm of objective knowledge leads to a philosophically unbalanced standpoint which presupposes a creative subject and at the same time neglects it. Finally, I question Popper's account of the growth of world 3. Popper considers only cognitive motivations, and excludes a broad range of motivating factors which originate in the problems which we face in our lives, and affect our cognitive interests in world 3. (shrink)

The discovery of the importance of mereology follows and does not precede the formalisation of the theory. In particular, it was only after the construction of an axiomatic theory of the part-whole relation by the Polish logician Stanisław Leśniewski that any attempt was made to reinterpret some periods in the history of philosophy in the light of the theory of parts and wholes. Secondly, the push for formalisation - and the individuation of mereology as a specific theoretical field - arise (...) from several particular theories, first from biology and then from psychology. Mereological considerations were explicitly developed within the school of Brentano, by Brentano himself- starting from the problem of the unity of consciousness - and by his students, particularly Stumpl, Twardowski and the Gestaltists. The most complete result of this tradition is undoubtedly the third of Husserl's Logical Investigations, called "the single most important contribution to realist (Aristotelian) ontology in the modern period". (shrink)

A brief review of the historicalrelation between logic and ontologyand of the opposition between the viewsof logic as language and logic as calculusis given. We argue that predication is morefundamental than membership and that differenttheories of predication are based on differenttheories of universals, the three most importantbeing nominalism, conceptualism, and realism.These theories can be formulated as formalontologies, each with its own logic, andcompared with one another in terms of theirrespective explanatory powers. After a briefsurvey of such a comparison, we argue (...) that anextended form of conceptual realism provides themost coherent formal ontology and, as such, canbe used to defend the view of logic as language. (shrink)

We observe that Putnam’s model-theoretic argument against determinacy of the concept of second-order quantification or that of the set is harmless to the nominalist. It serves as a good motivation for the nominalist philosophy of mathematics. But in the end it can lead to a serious challenge to the nominalist account of mathematical objectivity if some minimal assumptions about the relation between mathematical objectivity and logical objectivity are made. We consider three strategies the nominalist might take to meet this challenge, (...) and we argue that all these strategies are untenable. (shrink)

Nominalists are confronted with a grave difficulty: if abstract objects do not exist, what explains the success of theories that invoke them? In this paper, I make headway on this problem. I develop a formal language in which certain platonistic claims about properties and certain nominalistic claims can be expressed, develop a formal language in which only certain nominalistic claims can be expressed, describe a function mapping sentences of the first language to sentences of the second language, and prove some (...) facts about that function and facts about some sound logics for those languages. In doing so, I prove that, given some plausible metaphysical assumptions, a large class of sentences about properties of concrete objects are “safe” on nominalistic grounds. Whenever some true sentences about concrete objects and some sentences belonging to this class that are true according to platonists collectively entail a conclusion about concrete objects, some nominalistically acceptable sentences are true and entail the same conclusion. Because the proof can itself be formulated without abstract objects, it provides a nominalistic explanation of the success of theories that invoke properties of concrete objects. (shrink)