Non‐Humean theories of natural necessity invoke modally‐laden primitives to explain why nature exhibits lawlike regularities. However, they vary in the primitives they posit and in their subsequent accounts of laws of nature and related phenomena (including natural properties, natural kinds, causation, counterfactuals, and the like). This article provides a taxonomy of non‐Humean theories, discusses influential arguments for and against them, and describes some ways in which differences in goals and methods can motivate different versions of non‐Humeanism (and, for that matter, (...) Humeanism). In short, this article provides an introduction to non‐Humeanism concerning the metaphysics of laws of nature and natural necessity. (shrink)

Unity of science was once a very popular idea among both philosophers and scientists. But it has fallen out of fashion, largely because of its association with reductionism and the challenge from multiple realisation. Pluralism and the disunity of science are the new norm, and higher-level natural kinds and special science laws are considered to have an important role in scientific practice. What kind of reductionism does multiple realisability challenge? What does it take to reduce one phenomenon to another? How (...) do we determine which kinds are natural? What is the ontological basis of unity? In this Element, Tuomas Tahko examines these questions from a contemporary perspective, after a historical overview. The upshot is that there is still value in the idea of a unity of science. We can combine a modest sense of unity with pluralism and give an ontological analysis of unity in terms of natural kind monism. This title is available as Open Access on Cambridge Core. (shrink)

This paper shows how a niche account of the metaphysics of laws of nature and physical properties—the Powers-BSA—can underpin both a sense in which the laws are metaphysically necessary and a sense in which it is true that the laws could have been different. The ability to reconcile entrenched disagreement should count in favour of a philosophical theory, so this paper constitutes a novel argument for the Powers-BSA by showing how it can reconcile disagreement about the laws’ modal status. This (...) paper also constitutes a defence of modal necessitarianism, the interesting and controversial view according to which all worlds are nomologically identical, because it shows how the modal necessitarian can appease the orthodox contingentist about laws. (shrink)

The practice of scientific modelling often resorts to hypothetical, false, idealised, targetless, partial, generalised, and other types of modelling that appear to have at least partially non-actual targets. In this paper, I will argue that we can avoid a commitment to non-actual targets by sketching a framework where models are understood as having networks of possibilities as their targets. This raises a further question: what are the truthmakers for the modal claims that we can derive from models? I propose that (...) we can find truthmakers for the modal claims derived from models in actuality, even in the case of supposedly non-actual targets. I then put this framework to use by examining a case study concerning the modelling of superheavy elements. (shrink)

Natural kind essentialism is a specification of the intuitive idea that there are some mind-independent or objective categories in nature. These categories are thought to be characterised by a shared essence, which may involve intrinsic or extrinsic properties, mechanisms, or causal history. While the ontological basis of natural kinds has its roots in antiquity and especially Aristotle, the contemporary notion of a “natural kind” in philosophical discussion is often traced to William Whewell’s and John Stuart Mill’s work in the 1800s. (...) In its more modern form, natural kind essentialism was popularised in the 1970s mainly by Saul Kripke and Hilary Putnam. Traditionally, natural kind essentialism has been associated with intrinsic and microstructural properties, but contemporary work has made it clear that more refined versions of natural kind essentialism may have to accept extrinsic or relational essences. (shrink)

A common feature of all standard theories of the laws of nature is that they are "absolutist": They take laws to be either all metaphysically necessary or all contingent. Science, however, gives us reason to think that there are laws of both kinds, suggesting that standard theories should make way for "non-absolutist" alternatives: theories which accommodate laws of both modal statuses. In this paper, we set out three explanatory challenges for any candidate non-absolutist theory and discuss the prospects of the (...) two extant candidates in light of these challenges. We then develop our own non-absolutist theory, the essentialist DTA account, which combines the nomic-necessitation or DTA account with an essentialist approach to metaphysical modality in order to meet the three explanatory challenges. Finally, we argue that the distinction between kinematical and dynamical laws found in physical theories supports both non-absolutism in general and our proposed essentialist DTA view in particular. (shrink)

In a recent paper, Tuomas Tahko has argued for a hybrid view of the laws of nature, according to which some physical laws are metaphysically necessary, while others are metaphysically contingent. In this paper, we show that his criterion for distinguishing between these two kinds of laws — which crucially relies on the essences of natural kinds — is on its own unsatisfactory. We then propose an alternative way of drawing the metaphysically necessary/contingent distinction for laws of physics based on (...) the central kinematical/dynamical distinction used in physical theorising, and argue that the criterion can be used to amend Tahko’s own account, but also that it can be combined with different metaphysical views about the source of necessity. (shrink)

On what I call absolutist essentialism about modality (AE), the metaphysical necessities are the propositions that are true in virtue of the essence (i.e. Aristotelian, absolute essence) of some entities. Other kinds of necessity can then be defined by restriction – e.g. the conceptual necessities are the propositions that are true in virtue of the essence of conceptual entities specifically. As an account of metaphysical modality and some other kinds (e.g. logical, conceptual), AE may have important virtues. However, when it (...) comes to accounting for further important kinds, like natural or normative necessity, it faces a challenge. Three main options have been defended: treat those kinds as further restricted forms of metaphysical necessity; define them as conditional forms of metaphysical necessity; treat them as primitive kinds. -/- In this paper, I propose a new option, which combines the main idea of AE (reducing necessities to essences) with an idea which has been developed largely independently: that of relative essence. On the proposed view, those kinds (e.g. natural necessity) that cannot be grounded in the essences (i.e. absolute essences) of the relevant entities (e.g. natural entities) may be grounded in their relative essences instead. Thus, I propose a generalized, or extended, version of AE, which I call relativized essentialism about modality (RE). In particular, RE offers prospects for a general framework for kinds of modality which is flexible enough to cover a large range of kinds (both absolute and relative ones) while remaining parsimonious and unified. (shrink)

In this paper, we show that it is not a conceptual truth about laws of nature that they are immutable (though we are happy to leave it as an open empirical question whether they do actually change once in a while). In order to do so, we survey three popular accounts of lawhood—(Armstrong-style) necessitarianism, (Bird-style) dispositionalism and (Lewis-style) ‘best system analysis’—and expose the extent, as well as the philosophical cost, of the amendments that should be enforced in order to leave (...) room for the possibility of changing laws. (shrink)

Can the neo-Aristotelian uphold a pluralist substance ontology while taking seriously the recent arguments in favour of monism based on quantum holism and other arguments from quantum mechanics? In this article, Jonathan Schaffer’s priority monism will be the main target. It will be argued that the case from quantum mechanics in favour of priority monism does face some challenges. Moreover, if the neo-Aristotelian is willing to consider alternative ways to understand ‘substance’, there may yet be hope for a pluralist substance (...) ontology. A speculative case for such an ontology will be constructed based on primitive incompatibility. (shrink)

In this paper, I raise a novel objection to David Lewis’s Humean account of laws. The objection is that non-universal laws are metaphysically possible, but Lewis’s account cannot accommodate them. I then propose and defend an extension of Lewis’s view that gives us an account of Humean non-universal laws.

In this paper, I will defend the thesis that fundamental natural laws are distinguished from accidental empirical generalizations neither by metaphysical necessity, 147–155, 2005, 2007) nor by contingent necessitation. The only sort of modal force that distinguishes natural laws, I will argue, arises from the peculiar physical property of mutual independence of elementary interactions exemplifying the laws. Mutual independence of elementary interactions means that their existence and their nature do not depend in any way on which other interactions presently occur. (...) It is exactly this general physical property of elementary interactions in the actual world that provides natural laws with their specific modal force and grounds the experience of nature’s ‘recalcitrance’. Thus, the modal force of natural laws is explained by contingent non-modal properties of nature. In the second part of the paper, I deal with some alleged counterexamples to my approach: constraint laws, compositional laws, symmetry principles and conservation laws. These sorts of laws turn out to be compatible with my approach: constraint laws and compositional laws do not represent the dynamics of interaction-types by themselves, but only as constitutive parts of a complete set of equations, whereas symmetry principles and conservation laws do not represent any specific dynamics, but only impose general constraints on possible interactions. (shrink)

Properties have an important role in specifying different views on laws of nature: virtually any position on laws will make some reference to properties, and some of the leading views even reduce laws to properties. This chapter will first outline what laws of nature are typically taken to be and then specify their connection to properties in more detail. We then move on to consider three different accounts of properties: natural, essential, and dispositional properties, and we shall see that different (...) conceptions of properties also result in different views of the modal status of laws, such as the question of whether laws are metaphysically necessary or contingent. Finally, there are also important links specifically between properties, natural kinds, and laws of nature that deserve our attention. (shrink)

Two approaches to elevating certain laws of nature over others have come to prominence recently. On the one hand, according to the meta-laws approach, there are meta-laws, laws which relate to laws as those laws relate to particular facts. On the other hand, according to the modal, or non-absolutist, approach, some laws are necessary in a stricter sense than others. Both approaches play an important role in current research, questioning the ‘orthodoxy’ represented by the leading philosophical theories of natural laws—Humeanism, (...) the DTA view, dispositional essentialism and primitivism. This paper clarifies the relations between these two emerging approaches, as well as their applicability to physical laws and the status of the challenges they pose for standard theories of laws of nature. We first argue that, despite some significant similarities between the two approaches (especially in the context of Lange’s counterfactual account of laws), they are in general distinct and largely independent of each other. Then, we argue that the support for meta-laws from physical theory and practice is more questionable than usually presented. (shrink)

An important task for metaphysicians and philosophers of science is to account for laws of nature – in particular, how they distinguish themselves from ‘mere’ regularities, and the modal force they are endowed with, ‘natural necessity’. Dispositional essentialism about laws is roughly the view that laws distinguish themselves by being grounded in the essences of natural entities. This paper does not primarily concern how essentialism compares to its main rivals – Humeanism and Armstrongeanism. Rather, it distinguishes and comparatively assesses various (...) brands of essentialism – which mainly differ as to where exactly they take laws to find their essentialist sources, and what they take to be the targets of laws, namely what they apply to. Yet, this internal comparison is not unrelated to the more general debate about laws: the main criteria with which I compare these essentialist views concern how they can deal with some of the main objections faced by essentialism in general, and how they can keep what is arguably the main intuitive advantage of essentialism over its rivals. Thus, the paper also concerns the relative position of essentialism in the larger debate about laws – ultimately bringing support to it. (shrink)

This book argues for the importance and commonness of reasonings concerning impossibilities. Its aim is twofold – descriptive and constructive. Since hypothetical reasoning about impossibilities calls for explanation, the book provides a comprehensive guide through popular semantic theories of conditionals. Each is examined from the perspective of the question of impossibilities and the logic and metaphysics surrounding them. This provides the ground for a further aim. In the final chapter, I endeavor to combine the best features of the existing theories (...) and explore the possibility of a novel hybrid account. (shrink)