I argue that disposition ascriptions—claims like ‘the glass is fragile’—are semantically equivalent to possibility claims: they are true when the given object manifests the disposition in at least one of the relevant possible worlds.

Metaphysics of Science is the philosophical study of key concepts that figure prominently in science and that, prima facie, stand in need of clarification. It is also concerned with the phenomena that correspond to these concepts. Exemplary topics within Metaphysics of Science include laws of nature, causation, dispositions, natural kinds, possibility and necessity, explanation, reduction, emergence, grounding, and space and time. Metaphysics of Science is a subfield of both metaphysics and the philosophy of science—that is, it can be allocated to (...) either, but it exhausts neither. Unlike metaphysics simpliciter, Metaphysics of Science is not primarily concerned with metaphysical questions that may already arise from everyday phenomena such as what makes a thing (a chair, a desk) the very thing it is, what its identity criteria are, out of which parts is it composed, whether it remains the same if we exchange a couple of its parts, and so forth. Nor is it concerned with the concrete entities (superstrings, molecules, genes, and so forth) postulated by specific sciences; these issues are the subject matter of the special philosophies of science (for example, of physics, of chemistry, of biology). Metaphysics of Science is concerned with more abstract and general concepts that inform all of these sciences. Many of these concepts are interwoven with each other. For example, metaphysicians of science inquire whether dispositionality, lawhood, and causation can be accounted for in nonmodal terms; whether laws of nature presuppose the existence of natural kinds; and whether the properties of macrolevel objects supervene on dispositional or nondispositional properties. This article surveys the scope (section 1), historical origin (section 2), exemplary subject matters (section 4), and methodology (section 5) of Metaphysics of Science, as well as the motivation that drives it (section 3). (shrink)

When it comes to scientific explanation, our parsimonious tendencies mean that we focus almost exclusively on those dispositions whose manifestations result in some sort of change – changes in properties, locations, velocities and so on. Following this tendency, our notion of causation is one that is inherently dynamic, as if the maintenance of the status quo were merely a given. Contrary to this position, I argue that a complete concept of causation must also account for dispositions whose manifestations involve no (...) changes at all, and that a causal theory that fails to include these ‘static’ dispositions alongside the dynamic ones renders static occurrences miraculous. (shrink)

Individual objects have potentials: paper has the potential to burn, an acorn has the potential to turn into a tree, some people have the potential to run a mile in less than four minutes. Barbara Vetter provides a systematic investigation into the metaphysics of such potentials, and an account of metaphysical modality based on them. -/- In contemporary philosophy, potentials have been recognized mostly in the form of so-called dispositions: solubility, fragility, and so on. Vetter takes dispositions as her starting (...) point, but argues for and develops a more comprehensive conception of potentiality. She shows how, with this more comprehensive conception, an account of metaphysical modality can be given that meets three crucial requirements: Extensional correctness: providing the right truth-values for statements of possibility and necessity; formal adequacy: providing the right logic for metaphysical modality; and semantic utility: providing a semantics that links ordinary modal language to the metaphysics of modality. -/- The resulting view of modality is a version of dispositionalism about modality: it takes modality to be a matter of the dispositions of individual objects. This approach has a long philosophical tradition going back to Aristotle, but has been largely neglected in contemporary philosophy. In recent years, it has become a live option again due to the rise of anti-Humean, powers-based metaphysics. The aim of Potentiality is to develop the dispositionalist view in a way that takes account of contemporary developments in metaphysics, logic, and semantics. (shrink)

Dispositionality is a modal notion of a certain sort. When an object is said to have a disposition, we typically understand this to mean that under certain circumstances, the object would behave in a certain way. For instance, a fragile object is disposed to break when dropped onto a concrete surface. It need not actually break - its being fragile has implications that, so to speak, point beyond the actual world. According to dispositionalism, all modal features of the world may (...) be accounted for in terms of its dispositional features. My aim in this paper is to assess the prospects for dispositionalism by examining the most promising theories. Sections 1 and 2 clarify the assumptions and desiderata of a successful dispositionalist theory of modality. Section 3 introduces the principles governing the dispositionalist theories that apparently meet the desiderata. Sections 4 through 6 show that dispositionalism nonetheless faces three problems: while dispositions help account for modal features of the world that are local, diachronic, or gradable, they cannot account for certain modal features of the world that are global, synchronic, or absolute. I end by discussing the costs of preserving dispositionalism. (shrink)

Actualists of a certain stripe—dispositionalists—hold that metaphysical modality is grounded in the powers of actual things. Roughly: p is possible iff something has, or some things have, the power to bring it about that p. Extant critiques of dispositionalism focus on its material adequacy, and question whether there are enough powers to account for all the possibilities we intuitively want to countenance. For instance, it seems possible that none of the actual contingent particulars ever existed, but it is impossible to (...) explain this by appealing to the powers of some actual thing or things to bring it about. I argue instead that dispositionalism, in the simple form championed by its proponents, is formally inadequate. Dispositionalists interpret the modal operators as simple existential claims about powers, but if we interpret the operators that way, the resulting system of modal logic is too weak to capture metaphysical modality. I argue that we can modify the standard dispositionalist interpretations of the operators to secure formal adequacy, but at the cost of accepting that not all modality is grounded in powers. This, I shall suggest, is not a bad thing—the resulting theory still has powers at its core and has certain attractive features, in addition to formal adequacy, that the standard theory lacks. (shrink)

Dispositions are modal properties. The standard conception of dispositions holds that each disposition is individuated by its stimulus condition(s) and its manifestation(s), and that their modality is best captured by some conditional construction that relates stimulus to manifestation as antecedent to consequent. I propose an alternative conception of dispositions: each disposition is individuated by its manifestation alone, and its modality is closest to that of possibility — a fragile vase, for instance, is one that can break easily. The view is (...) expounded in some detail and defended against the major objections. (shrink)

Causation is everywhere in the world: it features in every science and technology. But how much do we understand it? Mumford and Anjum develop a new theory of causation based on an ontology of real powers or dispositions. They provide the first detailed outline of a thoroughly dispositional approach, and explore its surprising features.

This paper surveys recent "new actualist" approaches to modality that do without possible worlds and locate modality squarely in the actual world. New actualist theories include essentialism and dispositionalism about modality, each of which can come in different varieties. The commonalities and differences between these views, as well as their shared motivations, are layed out.

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.

George Molnar came to see that the solution to a number of the problems of contemporary philosophy lay in the development of an alternative to Hume's metaphysics. This alternative would have real causal powers at its centre. Molnar set about developing a thorough account of powers that might persuade those who remained, perhaps unknowingly, in the grip of Humean assumptions. He succeeded in producing something both highly focused and at the same time wide-ranging. He showed both that the notion of (...) a power was central and that it could serve to dispel a number of long-standing philosophical problems.Molnar's account of powers is as realist as any that has so far appeared. He shows that dispositions are as real as any other properties. Specifically, they do not depend for their existence on their manifestations. Nevertheless, they are directed towards such manifestations. Molnar thus appropriates the notion of intentionality, from Brentano, and argues that it is the essential characteristic of powers. He offers a persuasive case for there being some basic and ungrounded powers, thus ruling out the reducibility of the dispositional to the non-dispositional. However, he does allow that there are non-power properties as well as power properties. In this respect, his final position is dualistic.This is contemporary metaphysics of the highest quality. It is a work that was almost complete when its author died. It has been edited for publication by another specialist in the subject, Stephen Mumford, who has also provided an introduction that will allow non-specialists to become acquainted with the issues. David Armstrong, one of the greatest living metaphysicians and personal friend of George Molnar, has provided a Foreword. (shrink)

Possible worlds, concrete or abstract as you like, are irrelevant to the truthmakers for modality—or so I shall argue in this paper. First, I present the neo-Humean picture of modality, and explain why those who accept it deny a common sense view of modality. Second, I present what I take to be the most pressing objection to the neo-Humean account, one that, I argue, applies equally well to any theory that grounds modality in possible worlds. Third, I present an alternative, (...) properties-based theory of modality and explore several specific ways to flesh the general proposal out, including my favored version, the powers theory. And, fourth, I offer a powers semantics for counterfactuals that each version of the properties-based theory of modality can accept, mutatis mutandis. Together with a definition of possibility and necessity in terms of counterfactuals, the powers semantics of counterfactuals generates a semantics for modality that appeals to causal powers and not possible worlds. (shrink)

Based on the author's nearly 30 years' of teaching introductory philosophy — and his observations of where beginning readers run into difficulty — this compact “primer” gives readers the basic tools they need to explore philosophical reading and writing for the first time. Provides insights and strategies for helping readers get started with reading, thinking about, and discussing philosophical concepts and writing short philosophical essays about what they've been reading and thinking; includes a new chapter that illustrates techniques for probing (...) beneath the expository surface of a given question to uncover the inevitable structure of presuppositions and problems underlying it. (shrink)

In this paper, I distinguish between two varieties of actualism—hardcore actualism and softcore actualism—and I critically discuss Ross Cameron’s recent arguments for preferring a softcore actualist account of the truthmakers for modal truths over hardcore actualist ones. In the process, I offer some arguments for preferring the hardcore actualist account of modal truthmakers over the softcore actualist one.

Analyses of dispositional ascriptions in terms of conditional statements famously confront the problems of finks and masks. We argue that conditional analyses of dispositions, even those tailored to avoid finks and masks, face five further problems. These are the problems of: (i) Achilles' heels, (ii) accidental closeness, (iii) comparatives, (iv) explaining context sensitivity, and (v) absent stimulus conditions. We conclude by offering a proposal that avoids all seven of these problems.

This paper attempts to locate, within an actualist ontology, truthmakers for modal truths: truths of the form or . In Sect. 1 I motivate the demand for substantial truthmakers for modal truths. In Sect. 21 criticise Armstrong's account of truthmakers for modal truths. In Sect. 31 examine essentialism and defend an account of what makes essentialist attributions true, but I argue that this does not solve the problem of modal truth in general. In Sect. 41 discuss, and dismiss, a theistic (...) account of the source of modal truth proposed by Alexander Pruss. In Sect. 5 I offer a means of (dis)solving the problem. (shrink)

Many years ago, C.B. Martin drew our attention to the possibility of ‘finkish’ dispositions: dispositions which, if put to the test would not be manifested, but rather would disappear. Thus if x if finkishly disposed to give response r to stimulus s, it is not so that if x were subjected to stimulus r, x would give response z; so finkish dispositions afford a counter‐example to the simplest conditional analysis of dispositions. Martin went on to suggest that finkish dispositions required (...) a theory of primitive causal powers; there, I think, he was mistaken. All that they require is an improved conditional analysis, and this improved analysis can be built upon whatever treatments of properties and of laws we may favour on other grounds. (shrink)

– The paper defends a naturalistic version of modal actualism according to which what is metaphysically possible is determined by dispositions found in the actual world. We argue that there is just one world—this one—and that all genuine possibilities are anchored by the dispositions exemplified in this world. This is the case regardless of whether or not those dispositions are manifested. As long as the possibility is one that would obtain were the relevant disposition manifested, it is a genuine possibility. (...) Furthermore, by starting from actual dispositional properties and branching out, we are able to include possibilities that are quite far removed from any state of affairs that happens to obtain, while still providing a natural and actual grounding of possibility. Stressing the importance of ontological considerations in any theory of possibility, it is argued that the account of possibility in terms of dispositional properties provides a more palatable ontology than those of its competitors. Coming at it from the other direction, the dispositional account of possibility also provides motivation for taking an ontology of dispositions more seriously. As well as the relevant dispositional notions required to lay out the view, the paper discusses the dispositional realism needed as the basis for the account of possibility. (shrink)

If one’s solution to the free will problem is in terms of real causal powers of agents then one ought to be an incompatibilist. Some premises are contentious but the following new argument for incompatibilism is advanced: 1. If causal determinism is true, all events are necessitated2. If all events are necessitated, then there are no powers3. Free will consists in the exercise of an agent’s powersTherefore, if causal determinism is true, there is no free will; which is to say (...) that free will is incompatible with determinism, so compatibilism is false. (shrink)

There has been much discussion of powers or real dispositions in the past decade, but there remains an issue that has been inadequately treated. This concerns the precise modal value that comes with dispositionality. We contend in this paper that dispositionality involves a non-alethic, sui generis, irreducible modality. Dispositions only tend towards their manifestations; they do not necessitate them. Tendency is, of course, a dispositional term itself, so this last statement offers little by way of illumination. But given our thesis (...) on the irreducible nature of dispositionality, we maintain that it cannot be explicated correctly in non-dispositional terms. Nevertheless, we all have experience of dispositionality at work, through the exercise or our own powers and the action of other powers upon us. The notion of dispositionality that we acquire is one that involves a modality stronger than pure contingency but weaker than necessity. The recognition of this distinct modal value for dispositionality is one of the biggest oversights in the growing literature in the area. Yet it is there for all to see in even the most mundane example. (shrink)

Professional philosophers and advanced students working in metaphysics and the philosophy of science will find this book both provocative and stimulating.

Previous theories of the relationship between dispositions and conditionals are unable to account for the fact that dispositions come in degrees. We propose a fix for this problem that has the added benefit of avoiding the classic problems of finks and masks.

A number of theories of dispositions to date have presupposed that dispositions are all causal: when X is disposed to PHI in circumstances C, it is because of a potential causal connection between C and X’s PHIing. Other intimate connections between dispositions and causation have been argued for: that the relation between dispositions and their categorical bases is to be understood in causal terms, for example, or even that we can explain causation in dispositional terms. These theories of dispositions are (...) all threatened by previously underappreciated cases of noncausal dispositions: cases where an X is disposed to PHI in C, but not because of potential causal connections between the manifestation conditions of dispositions and the manifestations themselves. This paper argues that there are noncausal dispositions of a number of different varieties, explains what trouble this causes many standard theories of dispositions, and discusses what lessons can be learned from these cases for the nature of dispositions. Some of the cases discussed will also cast doubt on the idea that all dispositions ground truths about potentiality or possibility. (shrink)