I look at a recent argument offered in defense of a doctrine which I will call generalized scientific essentialism. This is the doctrine according to which, not only are some facts about substance composition metaphysically necessary, but, in addition, some facts about substance behavior are metaphysically necessary. More specifically, so goes the argument, not only is water necessarily composed of H2O and salt is necessarily composed of NaCl, but, in addition, salt necessarily dissolves in water. If this argument is sound, (...) and if the statement that necessarily salt dissolves in water is a statement of a law of nature, then one conclusion of the argument is that there is at least one metaphysically necessary law of nature. My paper examines the extent to which this kind of argument could be generalized to provide a case for a full-blown scientific essentialism: the doctrine according to which all of the laws of nature are necessary. Or, in terms of dispositions, it is the doctrine according to which natural kinds have all of their powers, capacities and propensities as a matter of necessity. (shrink)

This is a rewarding book. In terms of area, it has one foot firmly planted in metaphysics and the other just as firmly set in the philosophy of science. Nature's Metaphysics is distinctive for its thorough and detailed defense of fundamental, natural properties as essentially dispositional and for its description of how these dispositional properties are thus suited to sustain the laws of nature as (metaphysically) necessary truths.

In this paper I argue that it is not a priori that all the laws of nature are contingent. I assume that the fundamental laws are contingent and show that some non-trivial, a posteriori, non-basic laws may nonetheless be necessary in the sense of having no counterinstances in any possible world. I consider a law LS (such as 'salt dissolves in water') that concerns a substance S. Kripke's arguments concerning constitution show that the existence of S requires that a certain (...) deeper level law or variants thereof hold. At the same time, that law and its variants may each entail the truth of LS. Thus the existence of S entails LS. Consequently there is no world in which S exists and fails to obey LS. I consider the conditions concerning the fundamental laws that would make this phenomenon ubiquitous. I conclude with some consequences for metaphysics. (shrink)

Those who favour an ontology based on dispositions are thereby able to provide a dispositional essentialist account of the laws of nature. In part 1 of this paper I sketch the dispositional essentialist conception of properties and the concomitant account of laws. In part 2, I characterise various claims about the modal character of properties that fall under the heading ‘quidditism’ and which are consequences of the categoricalist view of properties, which is the alternative to the dispositional essentialist view. I (...) argue that quidditism should be rejected. In part 3, I address a criticism of a strong dispositional essentialist view, viz. that ‘structural’ (i.e. geometrical, numerical, spatial and temporal) properties must be regarded as categorical. (shrink)

I show that Armstrong’s view of laws as second-order contingent relations of ‘necessitation’ among categorical properties faces a dilemma. The necessitation relation confers a relation of extensional inclusion (‘constant conjunction’) on its relata. It does so either necessarily or contingently. If necessarily, it is not a categorical relation (in the relevant sense). If contingently, then an explanation is required of how it confers extensional inclusion. That explanation will need to appeal to a third-order relation between necessitation and extensional inclusion. The (...) same dilemma reappears at this level. Either Armstrong must concede that some properties are not categorical but have essential powers – or he is faced with a regress. (shrink)

Dispositional essentialism, a plausible view about the natures of (sparse or natural) properties, yields a satisfying explanation of the nature of laws also. The resulting necessitarian conception of laws comes in a weaker version, which allows differences between possible worlds as regards which laws hold in those worlds and a stronger version that does not. The main aim of this paper is to articulate what is involved in accepting the stronger version, most especially the consequence that all possible properties exist (...) in all worlds. I also suggest that there is no particularly strong reason for preferring the weaker to the stronger version. For example, Armstrong's instantiation condition on universals entails that according to strong necessitarianism every property is instantiated in all possible worlds. But first we do not need to accept Armstrong's instantiation condition, in part because his arguments for it are forceful only for a contingentist about laws and properties. Secondly, even if we do accept the condition, the consequence that all properties are instantiated is not itself contradictory, so long as any form of necessitarianism holds. Strong necessitarianism is prima facie counter-intuitive. But for that matter so is weak necessitarianism. Accepting either weak or strong necessitarianism requires denying the force of intuition in this area. And indeed we have every reason to deny the force of intuition and its primary source, imagination, concerning modal facts. (shrink)

In 'Necessarily, salt dissolves in water' (Analysis 61 (2001)), I argued that because the laws required for the existence of salt entail the laws that ensure dissolving in water, there is no possible world in which salt exists but fails to dissolve in water. In this paper I respond to criticisms from Helen Beebee and Stathis Psillos (Analysis 62 (2002)). I also introduce the 'down-and-up' structure, generalising the case. Whether or not this structure is instantiated is a matter for a (...) posteriori discovery. Hence not only are some laws necessary (but known a posteriori), but furthermore whether a given law is necessary or contingent will also be a matter of a posteriori discovery. (shrink)

In this paper I aim to show that a certain law of nature, namely that common salt (sodium chloride) dissolves in water, is metaphysically necessary. The importance of this result is that it conflicts with a widely shared intuition that the laws of nature (most if not all) are contingent. There have been debates over whether some laws, such as Newton’s second law, might be definitional of their key terms and hence necessary. But the law that salt dissolves in water (...) is not that kind of law. The law statement ‘salt dissolves in water’ is clearly synthetic. It appears a classic case of a contingent law. We like to believe that there are possible worlds in which the laws of nature are different and in which salt does not dissolve in water. (shrink)

Suppose it is a law that all Fs are G. Does the law hold in all possible worlds? According to Necessitarianism, it holds in at least all those worlds containing F-ness. I argue that the Necessitarian must also take the law to hold in all those possible worlds which do not contain F-ness. Accepting the principle that a law can only hold in a world if it has some ontological grounding in that world, I argue that Necessitarianism is committed to (...) the claim that any law holding in the actual world is grounded in every possible world, and that any law holding in any possible world is grounded in the actual world. In other words, Necessitarianism takes all possible laws to be actual. (shrink)

One view of the nature of properties has been crystallized in recent debate by an identity thesis proposed by Shoemaker. The general idea is that there is for behaviour. Well-known criticisms of this approach, however, remain unanswered, and the details of its connections to laws nothing more to being a particular causal property than conferring certain dispositions of nature and the precise ontology of causal properties stand in need of development. This paper examines and defends a dispositional essentialist account of (...) causal properties, combining a Shoemaker-type identity thesis with a Dretske, Tooley, and Armstrong-type view that laws are relations between properties, and a realism about dispositions. The property identity thesis is defended against standard epistemological and metaphysical objections. The metaphysics of causal properties is then clarified by a consideration of the laws relating them, vacuous laws, and ceteris paribus law statements. (shrink)

In this paper I discuss and evaluate different arguments for the view that the laws of nature are metaphysically necessary. I conclude that essentialist arguments from the nature of natural kinds fail to establish that essences are ontologically more basic than laws, and fail to offer an a priori argument for the necessity of all causal laws. Similar considerations carry across to the argument from the dispositionalist view of properties, which may end up placing unreasonable constraints on property identity across (...) possible worlds. None of my arguments preclude the possibility that the laws may turn out to be metaphysically necessary after all, but I argue that this can only be established by a posteriori scientific investigation. I therefore argue for what may seem to be a surprising conclusion: that a fundamental metaphysical question – the modal status of laws of nature – depends on empirical facts rather than purely on a priori reasoning. (shrink)

Necessitarian accounts of the laws of nature have an apparent difficulty in accounting for counterlegal conditionals because, despite appearing to be substantive, on the necessitarian thesis they are vacuous. I argue that the necessitarian may explain the apparently substantive content of such conditionals by pointing out the presuppositions of counterlegal discourse. The typical presupposition is that a certain conceptual possibility has been realized; namely, that necessitarianism is false. (The idea of conceptual possibility is explicated in terms of recent work in (...) two-dimensional modal semantics.) If this sort of presupposition is made explicit in counterlegal utterances, we obtain a sentence such as: 'If it turns out that the laws of nature are contingent, then if the laws had been otherwise, then such and such would have been the case.' Sentences of this type are non-vacuous, and very often true. I argue that this goes a long way towards resolving the difficulty for necessitarianism. (shrink)

Marc Lange objects to scientific essentialists that they can give no better account of the counterfactual invariance of laws than Humeans. While conceding this point succeeds ad hominem against some essentialists, I show that it does not undermine essentialism in general. Moreover, Lange's alternative account of the relation between laws and counterfactuals is - with minor modification - compatible with essentialism.

We argue that the inference from dispositional essentialism about a property (in the broadest sense) to the metaphysical necessity of laws involving it is invalid. Let strict dispositional essentialism be any view according to which any given property’s dispositional character is precisely the same across all possible worlds. Clearly, any version of strict dispositional essentialism rules out worlds with different laws involving that property. Permissive dispositional essentialism is committed to a property’s identity being tied to its dispositional profile or causal (...) role, yet is compatible with moderate interworld variation in a property’s dispositional profile. We provide such a model of dispositional essentialism about a property and metaphysical contingency of the laws involving it. (shrink)

I propose a different way of thinking about metaphysical and physical necessity: namely that the fundamental notion of necessity is what would ordinarily be called "truth in all physically possible worlds" – a notion which includes the standard physical necessities and the metaphysical ones as well; I suggest that the latter are marked off not as a stricter kind of necessity but by their epistemic status. One result of this reconceptualization is that the Descartes-Kripke argument against naturalism need no longer (...) trouble us. I end by relating the difference between my view and the standard view to the question, whether there could have been a different world than ours. (shrink)

This book advocates dispositional essentialism, the view that natural properties have dispositional essences.1 So, for example, the essence of the property of being negatively charged is to be disposed to attract positively charged objects. From this fact it follows that it is a law that all negatively charged objects will attract positively 10 charged objects; and indeed that this law is metaphysically necessary. Since the identity of the property of being negatively charged is determined by its being related in a (...) certain way to the property of being positively charged, in any world in which these properties exist they must be related so that all negatively charged objects attract positively charged objects. 15 Bird opposes his dispositional essentialism to the view that properties are categorical in nature, with their identities grounded in quiddities that are not exhausted by their relations to other properties. The main exponents of this view are D.M. Armstrong and David Lewis. They take the laws of nature to be contingent though they entertain very different views about their nature: Armstrong is a necessitarian 20 about laws, taking them to be relations of nomic necessitation between universals, while Lewis is a Humean about laws who takes them to be a special kind of regularity. The book is a sustained defence of the dispositional essentialist conception of properties and laws against the competing conceptions espoused by Armstrong and Lewis. One rough way to characterize the difference between these conceptions is to say that 25 the categoricalist sees properties as passive and inert with the laws of nature being fixed independently of the nature of properties whereas, in contrast, the dispositional essentialist sees properties as active potencies from which the laws of nature automatically spring. A slightly more tendentious way to express the difference is to say, as Bird does, that the categoricalist views embrace the Humean doctrine that there are no 30 necessary connexions in nature, while the dispositional essentialist view, on the other hand, repudiates this doctrine.. (shrink)

Laws of nature are puzzling because they have a ‘modal character’—they seem to be ‘necessary-ish’—even though they also seem to be metaphysically contingent. And it is hard to understand how contingent truths could have such a modal character. Scientific essentialism is a doctrine that seems to dissolve this puzzle, by showing that laws of nature are actually metaphysically necessary. I argue that even if the metaphysics of natural kinds and properties offered by scientific essentialism is correct, there are still some (...) metaphysically contingent truths that share the modal character of the laws of nature. I argue that these contingent truths should be considered laws of nature. So even if scientific essentialism is true, at least some laws of nature are metaphysically contingent. (shrink)

This paper concerns anti-Humean intuitions about connections in nature. It argues for the existence of a de re link that is not necessity. — Some anti-Humeans tacitly assume that metaphysical necessity can be used for all sorts of anti-Humean desires. Metaphysical necessity is thought to stick together whatever would be loose and separate in a Hume world, as if it were a kind of universal superglue. I argue that this is not feasible. Metaphysical necessity might connect synchronically co-existent properties—kinds and (...) their essential features, for example—but it is difficult to see how it could also serve as the binding force for successions of events. That is, metaphysical necessity seems not to be fit for diachronic, causal affairs in which causal laws, causation, or dispositions are involved. A different anti-Humean connection in nature has to do that job. My arguments focus mainly on a debate which has been the battleground for Humean vs. anti-Humean intuitions for many decades— namely, the analysis of dispositional predicates—but I believe (but do not argue here) that the arguments generalise to causation and causal laws straightforwardly. (shrink)

It is widely believed that at least two developments in the last third of the 20th century have given dispositionalism—the view that powers, capacities, potencies, etc. are irreducible real properties—new credibility: (i) the many counterexamples launched against reductive analyses of dispositional predicates in terms of counterfactual conditionals and (ii) a new anti-Humean faith in necessary connections in nature which, it is said, owes a lot to Kripke’s arguments surrounding metaphysical necessity. I aim to show in this paper that necessity is, (...) in fact, of little help for the dispositionalists. My argument makes use of one of the above mentioned counterexamples against Humean reduction: antidotes. Turning the tables, I ask how the dispositionalists themselves can deal with antidotes. The result will be to show that if the dispositionalists are to demystify antidote cases, they must make plausible a conceptualisation of dispositions that does not invoke any kind of necessity. I will cautiously suggest that the anti-Humean link dispositions bring to the world has to be thought of in terms of (Newtonian) forces. (shrink)

The striking difference between the orthodox nomological necessitation view of laws and the claims made recently by Scientific Essentialism is that on the latter interpretation laws are metaphysically necessary while they are contingent on the basis of the former. This shift is usually perceived as an upgrading: essentialism makes the laws as robust as possible. The aim of my paper—in which I contrast Brian Ellis’s Scientific Essentialism and David Armstrong’s theory of nomological necessity—is threefold. (1) I first underline the familiar (...) fact that metaphysical necessity (of Kripkean “water is necessarily H2O” kind) is not a stronger kind of necessity than nomological necessity but an entirely different kind of thing: nomological, but not metaphysical necessity, is an intra-world necessitation which Armstrong (almost) identifies with causation; metaphysical, but not nomological necessitation, has a canonical link to possible world considerations and counterfactual reasoning. Hence, the change from one necessity to the other is not an upgrading but a substantial shift. (2) I will explain how the essentialists, who promote this shift, are nonetheless able to retain the features of nomological necessity. (3) I also explore, for both the essentialist and the Armstrongian, whether they could extract a modal force from intra-world nomological necessity which it does not have per se. I argue that such a modal force is, indeed, obtainable for them. I will close the paper with some remarks and questions about the relation between Kripkean metaphysical necessity and the modal version of nomological necessity as defined in (3). (shrink)

That laws of nature play a vital role in explanation, prediction, and inductive inference is far clearer than the nature of the laws themselves. My hope here is to shed some light on the nature of natural laws by developing and defending the view that they involve genuine relations between properties. Such a position is suggested by Plato, and more recent versions have been sketched by several writers.~ But I am not happy with any of these accounts, not so much (...) because they lack detail or engender minor difficulties, though they do, but because they share a quite fundamental defect. My goal here is to make this defect clear and, more importantly, to present a rather different version of this general conception of laws that avoids it. I begin by considering several features of natural laws and argue that these are best explained by the view that laws involve properties, that this involvement takes the form of a genuine relation between properties, and, finally, that the relation is a metaphysically necessary one. In the second section I start at the other end, and by reflecting on the nature of properties arrive at a similar account of natural laws. In the final section I develop this account in more detail, with emphasis on the nature of the relation between properties it invokes. Along the way several natural objections to the account are answered. (shrink)