Reprint of the original, first published in 1869.

A modest proposal concerning laws, counterfactuals, and explanations - - Why be Humean? -- Suggestions from physics for deep metaphysics -- On the passing of time -- Causation, counterfactuals, and the third factor -- The whole ball of wax -- Epilogue : a remark on the method of metaphysics.

It is my aim in this paper to show that the contemporary assimilation of essence to modality is fundamentally misguided and that, as a consequence, the corresponding conception of metaphysics should be given up. It is not my view that the modal account fails to capture anything which might reasonably be called a concept of essence. My point, rather, is that the notion of essence which is of central importance to the metaphysics of identity is not to be understood in (...) modal terms or even to be regarded as extensionally equivalent to a modal notion. The one notion is, if I am right, a highly refined version of the other; it is like a sieve which performs a similar function but with a much finer mesh. (shrink)

This provocative book refurbishes the traditional account of freedom of will as reasons-guided "agent" causation, situating its account within a general metaphysics. O'Connor's discussion of the general concept of causation and of ontological reductionism v. emergence will specially interest metaphysicians and philosophers of mind.

The term ‘emergence’ often causes confusion in science and philosophy, as it is used to express at least two quite different concepts. We can label these concepts _strong_ _emergence_ and _weak emergence_. Both of these concepts are important, but it is vital to keep them separate.

In this paper, I argue for a new way of characterizing ontological emergence. I appeal to recent discussions in meta-ontology regarding fundamentality and dependence, and show how emergence can be simply and straightforwardly characterized using these notions. I then argue that many of the standard problems for emergence do not apply to this account: given a clearly specified meta-ontological background, emergence becomes much easier to explicate. If my arguments are successful, they show both a helpful way of thinking about emergence (...) and the potential utility of discussions in meta-ontology when applied to first-order metaphysics. (shrink)

Motivated by the seeming structure of the sciences, metaphysical emergence combines broadly synchronic dependence coupled with some degree of ontological and causal autonomy. Reflecting the diverse, frequently incompatible interpretations of the notions of dependence and autonomy, however, accounts of emergence diverge into a bewildering variety. Here I argue that much of this apparent diversity is superficial. I first argue, by attention to the problem of higher-level causation, that two and only two strategies for addressing this problem accommodate the genuine emergence (...) of special science entities. These strategies in turn suggest two distinct schema for metaphysical emergence---'Weak' and 'Strong' emergence, respectively. Each schema imposes a condition on the powers of entities taken to be emergent: Strong emergence requires that higher-level features have more token powers than their dependence base features, whereas Weak emergence requires that higher-level features have a proper subset of the token powers of their dependence base features. Importantly, the notion of “power” at issue here is metaphysically neutral, primarily reflecting commitment just to the plausible thesis that what causes an entity may bring about are associated with how the entity is---that is, with its features. (shrink)

I argue that an adequate account of non-reductive realization must guarantee satisfaction of a certain condition on the token causal powers associated with (instances of) realized and realizing entities---namely, what I call the 'Subset Condition on Causal Powers' (first introduced in Wilson 1999). In terms of states, the condition requires that the token powers had by a realized state on a given occasion be a proper subset of the token powers had by the state that realizes it on that occasion. (...) Accounts of non-reductive realization conforming to this condition are implementing what I call 'the powers-based subset strategy'. I focus on the crucial case involving mental and brain states; the results may be generalized, as appropriate. I first situate and motivate the strategy by attention to the problem of mental causation; I make the case, in schematic terms, that implementation of the strategy makes room (contra Kim 1989, 1993, 1998, and elsewhere) for mental states to be ontologically and causally autonomous from their realizing physical states, without inducing problematic causal overdetermination, and compatible with both Physicalism and Non-reduction; and I show that several contemporary accounts of non-reductive realization (in terms of functional realization, parthood, and the determinable/determinate relation) are plausibly seen as implementing the strategy. As I also show, implementation of the powers-based strategy does not require endorsement of any particular accounts of either properties or causation---indeed, a categoricalist contingentist Humean can implement the strategy. The schematic location of the strategy in the space of available responses to the problem of mental (more generally, higher-level) causation, as well as the fact that the schema may be metaphysically instantiated, strongly suggests that the strategy is, appropriately generalized and instantiated, sufficient and moreover necessary for non-reductive realization. I go on to defend the sufficiency and necessity claims against a variety of objections, considering, along the way, how the powers-based subset strategy fares against competing accounts of purportedly non-reductive realization in terms of supervenience, token identity, and constitution. (shrink)

This paper explores the fundamental ideas that have motivated the idea of emergence and the movement of emergentism. The concept of reduction, which lies at the heart of the emergence idea is explicated, and it is shown how the thesis that emergent properties are irreducible gives a unified account of emergence. The paper goes on to discuss two fundamental unresolved issues for emergentism. The first is that of giving a “positive” characterization of emergence; the second is to give a coherent (...) explanation of how “downward” causation, a central component of emergentism, is able to avoid the problem of overdetermination. (shrink)

What are the ontological commitments of a sentence? In this paper I offer an answer from the perspective of the truthmaker theorist that contrasts with the familiar Quinean criterion. I detail some of the benefits of thinking of things this way: they include making the composition debate tractable without appealing to a neo-Carnapian metaontology, making sense of neo-Fregeanism, and dispensing with some otherwise recalcitrant necessary connections.

Note: this is the first published presentation and defense of the 'proper subset strategy' for making sense of non-reductive physicalism or the associated notion of realization; this is sometimes, inaccurately, called "Shoemaker's subset strategy"; if people could either call it the 'subset strategy' or better yet, add my name to the mix I would appreciate it. Horgan claims that physicalism requires "superdupervenience" -- supervenience plus robust ontological explanation of the supervenient in terms of the base properties. I argue that Horgan's (...) account fails to rule out physically unacceptable emergence. I rather suggest that this and other unacceptable possibilities may be ruled out by requiring that each individual causal power in the set associated with a given supervenient property be numerically identical with a causal power in the set associated with its base property. I go on to show that a wide variety of physicalist accounts, both reductive and non-reductive, are implicitly or explicitly designed to meet this condition, and so are more similar than they seem. In particular, non-reductive physicalism accounts typically appeal to a relation plausibly ensuring that the powers of a higher-level property are a proper subset of those of its physical base property. (shrink)

The physicalist thesis that all entities are nothing over and above physical entities is often interpreted as appealing to a supervenience-based account of "nothing over and aboveness”, where, schematically, the A-entities are nothing over and above the B-entities if the A-entities supervene on the B-entities. The main approaches to filling in this schema correspond to different ways of characterizing the modal strength, the supervenience base, or the supervenience connection at issue. I consider each approach in turn, and argue that the (...) resulting formulation of physicalism is compatible with physicalism’s best traditional rival: a naturalist emergentism. Others have argued that supervenience-based formulations of physicalism fail. My aim here, besides addressing the full spectrum of supervenience-based approaches, is to show how certain philosophical and scientific theses concerning naturalism, properties, and laws give us new reasons to think that supervenience-based formulations of physicalism are untenable. (shrink)

All organised bodies are composed of parts, similar to those composing inorganic nature, and which have even themselves existed in an inorganic state; but the phenomena of life, which result from the juxtaposition of those parts in a certain manner, bear no analogy to any of the effects which would be produced by the action of the component substances considered as mere physical agents. To whatever degree we might imagine our knowledge of the properties of the several ingredients of a (...) living body to be extended and perfected, it is certain that no mere summing up of the separate actions of those elements will ever amount to the action of the living body itself. (shrink)

The following framework of theses, roughly hewn, shapes contemporary discussion of the problem of mental causation: (1) Non-Identity of the Mental and the Physical Mental properties and states cannot be identified with specific physical properties and states. (2) Causal Closure (Completeness) of the Physical The objective probability of every physical event is fixed by prior physical events and laws alone. (This thesis is sometimes expressed in terms of explanation: In tracing the causal history of any physical event, one need not (...) advert to any non-physical events or laws. To the extent that there is any explanation available for a physical event, there is a complete explanation available couched entirely in physical vocabulary. We prefer the probability formulation, as it should be acceptable to any physicalist, though some reject the explanation formulation.) (3) Causal Exclusion There is at most one complete and wholly independent explanation for any given event or sequence of events. (shrink)

The objective probability of every physical event is fixed by prior physical events and laws alone. (This thesis is sometimes expressed in terms of explanation: In tracing the causal history of any physical event, one need not advert to any non-physical events or laws. To the extent that there is any explanation available for a physical event, there is a complete explanation available couched entirely in physical vocabulary. We prefer the probability formulation, as it should be acceptable to any physicalist, (...) though some reject the explanation formulation.) (3) Causal Exclusion. (shrink)

Though most contemporary philosophers and scientists accept a physicalist view of mind, the recent surge of interest in the problem of consciousness has put the mind /body problem back into play. The physicalists' lack of success in dispelling the air of residual mystery that surrounds the question of how consciousness might be physically explained has led to a proliferation of options. Some offer alternative formulations of physicalism, but others forgo physicalism in favour of views that are more dualistic or that (...) bring in mentalistic features at the ground- floor level of reality as in pan-proto-psychism. My aim here is to give an overview of the recent philosophic discussion to serve as a map in locating issues and options. I will not offer a comprehensive survey of the debate or mark every important variant to be found in the recent literature. I will mark the principal features of the philosophic landscape that one might use as general orientation points in navigating the terrain. I will focus in particular on three central and interrelated ideas: those of emergence, reduction, and nonreductive physicalism. The third of these, which has emerged as more or less the majority view among current philosophers of mind, combines a pluralist view about the diversity of what needs to be explained by science with an underlying metaphysical commitment to the physical as the ultimate basis of all that is real. The view has been challenged from both left and right, on one side from dualists and on the other from hard core reductive materialists. Despite their differences, those critics agree in finding nonreductive physicalism an unacceptable and perhaps even incoherent position. They agree as well in treating reducibility as the essential criterion for physicality; they differ only about whether the criterion can be met. Reductive physicalists argue that it can, and dualists deny it. (shrink)

Why does the problem of free will seem so intractable? I surmise that in large measure it does so because the free will debate, at least in its modern form, is conducted in terms of a mistaken approach to causality in general. At the heart of this approach is the assumption that all causation is fundamentally event causation. Of course, it is well-known that some philosophers of action want to invoke in addition an irreducible notion of agent causation, applicable only (...) in the sphere of intelligent agency. But such a view is generally dismissed as incompatible with the naturalism that has now become orthodoxy amongst mainstream analytical philosophers of mind. What I want to argue is that substances, not events, are the primary relata of causal relations and that agent causation should properly be conceived of as a species of substance causation. I shall try to show that by thus reconceiving the nature of causation and of agency, the problem of free will can be made more tractable. I shall also argue for a contention that may seem even less plausible at first sight, namely, that such a view of agency is perfectly compatible with a volitionist theory of action. (shrink)

Though most contemporary philosophers and scientists accept a physicalist view of mind, the recent surge of interest in the problem of consciousness has put the mind/body problem back into play. The physicalists' lack of success in dispelling the air of residual mystery that surrounds the question of how consciousness might be physically explained has led to a proliferation of options. Some offer alternative formulations of physicalism, but others forgo physicalism in favour of views that are more dualistic or that bring (...) in mentalistic features at the ground- floor level of reality as in pan-proto-psychism. My aim here is to give an overview of the recent philosophic discussion to serve as a map in locating issues and options. I will not offer a comprehensive survey of the debate or mark every important variant to be found in the recent literature. I will mark the principal features of the philosophic landscape that one might use as general orientation points in navigating the terrain. I will focus in particular on three central and interrelated ideas: those of emergence, reduction, and nonreductive physicalism. The third of these, which has emerged as more or less the majority view among current philosophers of mind, combines a pluralist view about the diversity of what needs to be explained by science with an underlying metaphysical commitment to the physical as the ultimate basis of all that is real. The view has been challenged from both left and right, on one side from dualists and on the other from hard core reductive materialists. Despite their differences, those critics agree in finding nonreductive physicalism an unacceptable and perhaps even incoherent position. They agree as well in treating reducibility as the essential criterion for physicality; they differ only about whether the criterion can be met. Reductive physicalists argue that it can, and dualists deny it. (shrink)

This paper defends the traditional view that the laws of nature are contingent, or, if some of them are necessary, this is due to analytic principles for the individuation of the law-governed properties. Fundamentally, I argue that the supposed explanatory purposes served by taking the laws to be necessary --showing how laws support counterfactuals, how properties are individuated, or how we have knowledge of properties--are in fact undermined by the continued possibility of the imagined scenarios--this time, described neutrally--which seemed to (...) disprove the claim to necessity in the first place. I speculate that this will be true for any proposed necessary a posteriori truths, and is a basis for rejecting their supposed metaphysical significance. (shrink)

The nonlinearity of a composite system, whereby certain of its features (including powers and behaviors) cannot be seen as linear or other broadly additive combinations of features of the system's composing entities, has been frequently seen as a mark of metaphysical emergence, coupling the dependence of a composite system on an underlying system of composing entities with the composite system's ontological autonomy from its underlying system. But why think that nonlinearity is a mark of emergence, and moreover, of metaphysical rather (...) than merely epistemological emergence? Are there diverse ways in which nonlinearity might enter into an account of properly metaphysical emergence? And what are the prospects for there actually being phenomena that are metaphysically emergent in any available sense? Here I explore the mutual bearing of nonlinearity and metaphysical emergence, with an eye towards answering these and related questions. (shrink)

In a recent paper (Bird 2001), Alexander Bird argues that the law that common salt dissolves in water is metaphysically necessary - and he does so without presupposing dispositionalism about properties. If his argument were sound, it would thus show that at least one law of nature is meta- physically necessary, and it would do so without illicitly presupposing a position (dispositionalism) that is already committed to a necessitarian view of laws. I shall argue that Bird's argument is unsuccesful.