Timothy Williamson gives an original and provocative treatment of deep metaphysical questions about existence, contingency, and change, using the latest resources of quantified modal logic. Contrary to the widespread assumption that logic and metaphysics are disjoint, he argues that modal logic provides a structural core for metaphysics.

In order to perfectly describe the world, it is not enough to speak truly. One must also use the right concepts - including the right logical concepts. One must use concepts that "carve at the joints", that give the world's "structure". There is an objectively correct way to "write the book of the world". Much of metaphysics, as traditionally conceived, is about the fundamental nature of reality; in the present terms, this is about the world's structure. Metametaphysics - inquiry into (...) the status of metaphysical questions - turns on structure. The question of whether ontological, causal, or modal questions are "substantive" is in large part a question of whether the world has ontological, causal, and modal structure - whether quantifiers, causal relations, and modal operators carve at the joints. (shrink)

I defend a one category ontology: an ontology that denies that we need more than one fundamental category to support the ontological structure of the world. Categorical fundamentality is understood in terms of the metaphysically prior, as that in which everything else in the world consists. One category ontologies are deeply appealing, because their ontological simplicity gives them an unmatched elegance and spareness. I’m a fan of a one category ontology that collapses the distinction between particular and property, replacing it (...) with a single fundamental category of intrinsic characters or qualities. We may describe the qualities as qualitative charactersor as modes, perhaps on the model of Aristotelian qualitative (nonsubstantial) kinds, and I will use the term “properties” interchangeably with “qualities”. The qualities are repeatable and reasonably sparse, although, as I discuss in section 2.6, there are empirical reasons that may suggest, depending on one’s preferred fundamental physical theory, that they include irreducibly intensive qualities. There are no uninstantiated qualities. I also assume that the fundamental qualitative natures are intrinsic, although physics may ultimately suggest that some of them are extrinsic. On my view, matter, concrete objects, abstract objects, and perhaps even spacetime are constructed from mereological fusions of qualities, so the world is simply a vast mixture of qualities, including polyadic properties (i.e., relations). This means that everything there is, including concrete objects like persons or stars, is a quality, a qualitative fusion, or a portion of the extended qualitative fusion that is the worldwhole. I call my view mereological bundle theory. (shrink)

Science Without Numbers caused a stir in 1980, with its bold nominalist approach to the philosophy of mathematics and science. It has been unavailable for twenty years and is now reissued in a revised edition with a substantial new preface presenting the author's current views and responses to the issues raised in subsequent debate.

Every Thing Must Go aruges that the only kind of metaphysics that can contribute to objective knowledge is one based specifically on contemporary science as it ...

In 1931 Walter Sellar and Robert Yeatman published a delightfully silly history of England entitled 1066 and All That 2, as they said, “comprising, all the parts you can remember including one hundred and three good things, five bad kings, and two genuine dates”.3 History, they tell us, is not what you think; it is what you can remember. So their history is simplified and garbled, and the moral point is put front and center: every development is described as a (...) good thing or a bad thing, a good king or a bad king. What makes 1066... comic is the cleverness of its insight into what confusions people actually have and the antic candor in giving us the moral point without wasting any time on dates, motivations, or any other such confusing historical details. (shrink)

The theoretical virtue of parsimony values the minimizing of theoretical commitments, but theoretical commitments come in two kinds : ontological and ideological. While the ontological commitments of a theory are the entities it posits, a theory’s ideological commitments are the primitive concepts it employs. Here, I show how we can extend the distinction between quantitative and qualitative parsimony, commonly drawn regarding ontological commitments, to the domain of ideological commitments. I then argue that qualitative ideological parsimony is a theoretical virtue. My (...) defense proceeds by demonstrating the merits of qualitative ideological parsimony and by showing how the qualitative conception of ideological parsimony undermines two notable arguments from ideological parsimony: David Lewis’ defense of modal realism and Ted Sider’s defense of mereological nihilism. (shrink)

In this paper I articulate and defend a view that I call phenomenal dogmatism about intuitive justification. It is dogmatic because it includes the thesis: if it intuitively seems to you that p, then you thereby have some prima facie justification for believing that p. It is phenomenalist because it includes the thesis: intuitions justify us in believing their contents in virtue of their phenomenology—and in particular their presentational phenomenology. I explore the nature of presentational phenomenology as it occurs perception, (...) and I make a case for thinking that it is present in a wide variety of logical, mathematical, and philosophical intuitions. (shrink)

Available for the first time in 20 years, here are two important works from the 1920s by the best-known representative of the Vienna Circle.

Philosophers have ever declared that their problems lie at a different level from the problems of the empirical sciences. Perhaps one may agree with this assertion; the question is, however, where should one seek this level. The metaphysicians wish to seek their object behind the objects of empirical science; they wish to enquire after the essence, the ultimate cause of things. But the logical analysis of the pretended propositions of metaphysics has shown that they are not propositions at all, but (...) empty word arrays, which on account of notional and emotional connections arouse the false appearance of being propositions. This conception that the “propositions” of metaphysics, including those of ethics, have no theoretical content, is to be sure still disputed. We shall not, however, enter here on its demonstration, but, under its guidance, will limit ourselves to non-metaphysical and non-ethical philosophical problems. (shrink)

APA PsycNET abstract: This is the first volume of a two-volume work on Probability and Induction. Because the writer holds that probability logic is identical with inductive logic, this work is devoted to philosophical problems concerning the nature of probability and inductive reasoning. The author rejects a statistical frequency basis for probability in favor of a logical relation between two statements or propositions. Probability "is the degree of confirmation of a hypothesis (or conclusion) on the basis of some given evidence (...) (or premises)." Furthermore, all principles and theorems of inductive logic are analytic, and the entire system is to be constructed by means of symbolic logic and semantic methods. This means that the author confines himself to the formalistic procedures of word and symbol systems. The resulting sentence or language structures are presumed to separate off logic from all subjectivist or psychological elements. Despite the abstractionism, the claim is made that if an inductive probability system of logic can be constructed it will have its practical application in mathematical statistics, and in various sciences. 16-page bibliography. (PsycINFO Database Record (c) 2016 APA, all rights reserved). (shrink)

John Campbell investigates how consciousness of the world explains our ability to think about the world; how our ability to think about objects we can see depends on our capacity for conscious visual attention to those things. He illuminates classical problems about thought, reference, and experience by looking at the underlying psychological mechanisms on which conscious attention depends.

Over the last two or three decades, puzzles concerning vagueness, identity, and material constitution have led an increasing number of ontologists to “eliminate” at least some of the objects of folk ontology. In the book here reviewed, Trenton Merricks proposes to eliminate any and all material objects that lack nonredundant causal powers. The objects found lacking include statues, baseballs, planets, and all other inanimate macroscopica, including the masses and conjunctive objects favored by some other eliminativists. The objects found to possess (...) the requisite powers include human persons, who are taken to be human organisms, other conscious organisms, such as dogs and dolphins, and the microscopica of which organisms are composed. Merricks doesn’t assume that there are physical simples. But he does assume that there is at least one level of microscopica, and he uses ‘atoms’ as a convenient term for the microscopica of some unspecified level. As regards organisms that lack consciousness, Merricks is agnostic. (shrink)

Metaphysicians frequently appeal to the idea that theoretical simplicity is truth conducive in metaphysics, in the sense that, all other things being equal, simpler metaphysical theories are more likely to be true. In this paper I defend the notion that theoretical simplicity is truth conducive in metaphysics, against several recent objections. I do not give any direct arguments for the thesis that simplicity is truth conducive in metaphysics, since I am aware of no such arguments. I do argue, however, that (...) there is no special problem with the notion that simplicity is truth conducive in metaphysics. More specifically, I argue that if you accept the idea that simplicity is truth conducive in science, then it would be objectionably arbitrary to reject the idea that simplicity is truth conducive in metaphysics. (shrink)

Mereological nihilism (henceforth just "nihilism") is the thesis that composition never occurs. Nihilism has often been defended on the basis of its theoretical simplicity, including its ontological simplicity and its ideological simplicity (roughly, nihilism's ability to do without primitive mereological predicates). In this paper I defend nihilism on the basis of the theoretical unification conferred by nihilism, which is, roughly, nihilism's capacity to allow us to take fewer phenomena as brute and inexplicable. This represents a respect in which nihilism enjoys (...) greater theoretical simplicity than its rivals which has not yet been explored, and which is immune to many of the objections which have been leveled against previous arguments for nihilism from nihilism's theoretical simplicity. Composition as identity might be thought to confer a similar degree of theoretical unification as nihilism. I end the paper by arguing that this is not the case. (shrink)

Here we challenge the orthodoxy according to which abduction is an a posteriori mode of inference. We start by providing a case study illustrating how abduction can justify a philosophical claim not justifiable by empirical evidence alone. While many grant abduction's epistemic value, nearly all assume that abductive justification is a posteriori, on grounds that our belief in abduction's epistemic value depends on empirical evidence about how the world contingently is. Contra this assumption, we argue, first, that our belief in (...) abduction’s epistemic value is not and could not be justified a posteriori, and second, that attention to the roles experience plays in abductive justification supports taking abduction to be an a priori mode of inference. We close by highlighting how our strategy for establishing the a priority of abduction positively contrasts with strategies in Bonjour (1998), Swinburne (2001), and Peacocke (2004) aiming to establish the a priority of certain ampliative modes of inference or abductive principles. (shrink)

This paper introduces a modal epistemology that centers on inference to the best explanation (i.e. abduction). In introducing this abduction-centered modal epistemology, the paper has two main goals. First, it seeks to provide reasons for pursuing an abduction-centered modal epistemology by showing that this epistemology aids a popular stance on the mind-body problem and allows an appealing approach to modality. Second, the paper seeks to show that an abduction-centered modal epistemology can work by showing that abduction can establish claims about (...) necessity/possibility (i.e. modal claims)—where ‘necessity’ and ‘possibility’ denote metaphysical necessity and possibility, ways things may or may not have been given how they actually are. (shrink)

I argue for the claim in the title. Along the way, I also address an independently interesting question: what is metaphysics, anyway? I think that the typical characterizations of metaphysics are inadequate, that a better one is available, and that the better one helps explain why metaphysics is no more problematic than the rest of philosophy.

Metaphysical theories are beautiful. I mean it literally. At the end of this book, I defend the view that metaphysical theories possess aesthetic properties and that these play a crucial role when it comes to theory evaluation and theory choice. But this is the end of a long journey – a journey that is perhaps more important than the destination. Before we get there, the philosophical path I propose to follow starts with three discussions of metaphysical equivalence. I argue that (...) there are cases of metaphysical equivalence, cases of partial metaphysical equivalence, as well as interesting cases of theories that are not equivalent. Thus, claims of metaphysical equivalence can only be raised locally. My slogan is : the best way to do meta -metaphysics is to do first-level metaphysics. To do this work, I focus on the nature of primitives and on the role they play in each of the theories involved. I emphasize the utmost importance of primitives in the construction of metaphysical theories and in the subsequent evaluation of them. I then raise the simple but complicated question: how to make a choice between competing metaphysical theories? If two theories are equivalent, then perhaps we do not need to make a choice. But what about all the other cases of non-equivalent "equally good" theories? I use some of the theories discussed in the first part of the book as examples and I examine some traditional meta -theoretical criteria for theory choice only to show that they do not allow us to make a choice. But if the standard meta -theoretical criteria cannot help us in deciding between competing non-equivalent metaphysical theories, how then shall we make that choice? This is where I argue that metaphysical theories possess aesthetic properties – grounded in non-aesthetic properties – and that these play a crucial role in theory choice and evaluation. This view, as well as all the meta -metaphysical considerations discussed throughout the book, then naturally lead me to a form of anti-realism, and at the end of the journey I offer reasons to think better of the kind of anti-realist view I propose to embrace. (shrink)

Metaphysical theories are often counter-intuitive. But they also often are strongly supported and motivated by intuitions. One way or another, the link between intuitions and metaphysics is a strong and important one, and there is hardly any metaphysical discussion where intuitions do not play a crucial role. In this article, I will be interested in a particular kind of such intuitions, namely those that come, at least partly, from experience. There seems to be a route from experience to metaphysics, and (...) this is the core of my interest here. In order to better understand such ‘arguments from experience’ and the kind of relationship there is between this type of intuitions and metaphysical theories, I shall examine four particular cases where a kind of experience-based intuition seems to motivate or support a metaphysical theory. At the end of the day, I shall argue that this route is a treacherous one, and that in all of the four cases I shall concentrate on, phenomenological considerations are in fact orthogonal to the allegedly ‘corresponding’ metaphysical claims. An anti-realist view of metaphysics will emerge. (shrink)

Metaphysical theories are often counter‐intuitive. But they also often are strongly supported and motivated by intuitions. One way or another, the link between intuitions and metaphysics is a strong and important one, and there is hardly any metaphysical discussion where intuitions do not play a crucial role. In this article, I will be interested in a particular kind of such intuitions, namely those that come, at least partly, from experience. There seems to be a route from experience to metaphysics, and (...) this is the core of my interest here. In order to better understand such ‘arguments from experience’ and the kind of relationship there is between this type of intuitions and metaphysical theories, I shall examine four particular cases where a kind of experience‐based intuition seems to motivate or support a metaphysical theory. At the end of the day, I shall argue that this route is a treacherous one, and that in all of the four cases I shall concentrate on, phenomenological considerations are in fact orthogonal to the allegedly ‘corresponding’ metaphysical claims. An anti‐realist view of metaphysics will emerge. (shrink)

In my reply to michael devitt, It is argued, First, That quine fails to appreciate the force of plato's "one over many" argument for universals. It is argued, Second, That quine's failure springs in part at least from his doctrine of ontological commitment: from the view that predicates need not be treated with ontological seriousness. Finally, An attempt is made to blunt the force of devitt's contention that realists cannot give a coherent explanation of the way that universals stand to (...) particulars. (shrink)

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

This book argues that the only kind of metaphysics that can contribute to objective knowledge is one based specifically on contemporary science as it really is, and not on philosophers' a priori intuitions, common sense, or simplifications of science. In addition to showing how recent metaphysics has drifted away from connection with all other serious scholarly inquiry as a result of not heeding this restriction, this book demonstrates how to build a metaphysics compatible with current fundamental physics, which, when combined (...) with metaphysics of the special sciences, can be used to unify physics with the other sciences without reducing these sciences to physics itself. Taking science metaphysically seriously, this book argues, means that metaphysicians must abandon the picture of the world as composed of self-subsistent individual objects, and the paradigm of causation as the collision of such objects. The text assesses the role of information theory and complex systems theory in attempts to explain the relationship between the special sciences and physics, treading a middle road between the grand synthesis of thermodynamics and information, and eliminativism about information. The consequences of the books' metaphysical theory for central issues in the philosophy of science are explored, including the implications for the realism versus empiricism debate, the role of causation in scientific explanations, the nature of causation and laws, the status of abstract and virtual objects, and the objective reality of natural kinds. (shrink)

Arguments that ordinary inanimate objects such as tables and chairs, sticks and stones, simply do not exist have become increasingly common and increasingly prominent. Some are based on demands for parsimony or for a non-arbitrary answer to the special composition question; others arise from prohibitions against causal redundancy, ontological vagueness, or co-location; and others still come from worries that a common sense ontology would be a rival to a scientific one. Until now, little has been done to address these arguments (...) in a unified and systematic way. Ordinary Objects is designed to fill this gap, demonstrating that the mistakes behind all of these superficially diverse eliminativist arguments may be traced to a common source. It aims to develop an ontology of ordinary objects subject to no such problems, providing perhaps the first sustained defense of a common sense ontology in two generations. The work done along the way addresses a number of major issues in philosophy of language and metaphysics, contributing to debates about analyticity, identity conditions, co-location and the grounding problem, vagueness, overdetermination, parsimony, and ontological commitment. In the end, the most important result of addressing these eliminativist arguments is not merely avoiding their conclusions; examining their failings also gives us reason to suspect that many apparent disputes in ontology are pseudo-debates. For it brings into question widely-held assumptions about which uses of metaphysical principles are appropriate, which metaphysical demands are answerable, and how we should go about addressing such fundamental questions as "What exists?". As a result, the work of Ordinary Objects promises to provide not only the route to a reflective understanding of our unreflective common-sense view, but also a better understanding of the proper methods and limits of metaphysics. (shrink)

While fights about ontology rage on in the ring, there’s long been a suspicion whispered in certain corners of the stadium that some of the fights aren’t real. Granted the disputants all think they are really disagreeing—it’s not the sincerity of the serious ontologists that’s in question, but rather their judgment that they are engaged in a real debate about genuine issues of substance.

Knowledge and its Limits presents a systematic new conception of knowledge as a kind of mental stage sensitive to the knower's environment. It makes a major contribution to the debate between externalist and internalist philosophies of mind, and breaks radically with the epistemological tradition of analyzing knowledge in terms of true belief. The theory casts new light on such philosophical problems as scepticism, evidence, probability and assertion, realism and anti-realism, and the limits of what can be known. The arguments are (...) illustrated by rigorous models based on epistemic logic and probability theory. The result is a new way of doing epistemology and a notable contribution to the philosophy of mind. (shrink)

Précis for a book symposium, with contributions from Meg Wallace, Louis deRosset, and Chris Tillman and Joshua Spencer.

The relationship between formal logic and general philosophy is discussed under headings such as A Re-examination of Our Tense-Logical Postulates, Modal Logic in the Style of Frege, and Intentional Logic and Indeterminism.

According to Peter van Inwagen, visible inanimate objects do not, strictly speaking, exist. In defending this controversial thesis, he offers fresh insights on such topics as personal identity, commonsense belief, existence over time, the phenomenon of vagueness, and the relation between metaphysics and ordinary language.

According to epistemological internalism, the rationality of a belief supervenes purely on "internal facts" about the thinker's mind. But what are "internal facts"? Why does the rationality of a belief supervene on them? The standard answers are unacceptable. This paper proposes new answers. "Internal facts" are facts about the thinker's nonfactive mental states. The rationality of a belief supervenes on such internal facts because we need rules of belief revision that we can follow directly, not by means of following any (...) other rules, and the proximate explanation of any belief revision always consists of such internal facts. (shrink)

Available for the first time in 20 years, here are two important works from the 1920s by the best-known representative of the Vienna Circle.

Every paper in this collection is worth reading, for one reason or another. Still, due to certain problematic metametaphysical presuppositions most of these discussions miss the deeper mark, on the pessimist as well as the optimist side. My reasons for thinking this come from considering how best to answer three metametaphysical questions. First, why be pessimistic about metaphysics – why be Carnapian in a post-positivist age? There is, I’ll suggest, a post-positivist strategy for reviving Carnapian pessimism, but it is almost (...) entirely neglected here; and the motivations that pessimists offer instead are not compelling. Second, why think that the best way to approach metametaphysical questions is by attention to features of language, and in particular to quantifier semantics, in ordinary or ontological language(s)? Here again we are offered little motivation for this supposition, which, notwithstanding its acceptance by nearly all contributors, faces clear difficulties. Third, granting that quantification is somehow bound up with first-order questions about what exists, what is the nature of this connection, and what are the associated implications for metametaphysics? Here I find the accounts of the connection on offer implausible, especially as compared to an alternative that makes better sense of metaphysical practice and disagreement. The moral following consideration of these questions is that real progress in metametaphysics is likely to occur less by attention to semantic issues pertaining to representation, translation and quantification and more to non-semantic issues pertaining to epistemology and metaphysical determinacy. (shrink)