Humean Supervenience Research Articles

Bigger, Badder Bugs

Abstract In this paper we motivate the ‘principles of trust’, chance-credence principles that are strictly stronger than the New Principle yet strictly weaker than the Principal Principle, and argue, by proving some limitative results, that the principles of trust conflict with Humean Supervenience.

Laws beyond spacetime

Quantum gravity’s suggestion that spacetime may be emergent and so only exist contingently would force a radical reconception of extant analyses of laws of nature. Humeanism presupposes a spatiotemporal mosaic of particular matters of fact on which laws supervene; primitivism and dispositionalism conceive of the action of primitive laws or of dispositions as a process of ‘nomic production’ unfolding over time. We show how the Humean supervenience basis of non-modal facts and primitivist or dispositionalist accounts of nomic production can be reconceived, avoiding a reliance on fundamental spacetime. However, it is unclear that naturalistic forms of Humeanism can maintain their commitment to there being no necessary connections among distinct entities. Furthermore, non-temporal conceptions of production render this central concept more elusive than before. In fact, the challenges run so deep that the survival of the investigated analyses into the era of quantum gravity is questionable.

Branching with a Humean Face

Abstract This paper investigates the prospects of developing a branching modal framework while keeping with the spirit of Humean Supervenience. It is argued that such an approach is bound to face hard problems regarding haecceitism and the notion of recombination. Possible directions for future philosophical developments of branching frameworks are suggested.

Intrinsicality and Entanglement

AbstractI explore the relationship between a prominent analysis of intrinsic properties, due to Langton and Lewis, and the phenomenon of quantum entanglement. As I argue, the analysis faces a puzzle. The full analysis classifies certain properties of entangled particles as intrinsic. But when combined with an extremely plausible assumption about duplication, the main part of the analysis classifies those properties as non-intrinsic instead. I conclude that much of Lewis’s metaphysics is in trouble: Lewis based many of his metaphysical views—his thesis of Humean supervenience, for instance, and his account of recombination—on an analysis of intrinsicality which does not sit well with quantum phenomena.

Humean Idealism

ABSTRACT I outline a version of idealism that borrows from Humean Supervenience. The resulting theory is immune to what is often considered to be the most powerful anti-idealist argument, the gist of which is that the idealist can’t supply truthmakers (or an adequate supervenience base) for commonly accepted truths about the physical world. That charge has no purchase on Humean idealism.

Humeanismo y leyes de la naturaleza: alcance y límites

Nomological Humeanism has developed into a research program encompassing several variations on a single theme, namely, the view that laws are statements about regularities that we find in nature. After briefly revisiting an early form of nomological Humeanism in Hume’s critique of the idea of necessary connection, this article critically examines Lewis’ two-fold approach based on Humean supervenience and the best system account. We shall point out three limits of nomological Humeanism, which are widely recognized in the literature: its inadequacy in view of physical theories, its explanatory circularity, and its purported anthropomorphism, all of which advocates of nomological Humeanism have attempted to overcome Humeanism (Jaag y Loew 2020, Loewer 2004 y Massimi 2018). Lastly, we will argue that nomological Humeanism fails to provide a suitable notion of modality for laws of nature. This latter issue continues to represent a live challenge for empiricism in the philosophy of physical laws.

On Metaphysics’ Independence from Truthmaking. Or, Why Humean Supervenience is Compatible with the Growing Block Universe

This paper aims to support the claim that analytic metaphysics should be more cautious regarding the constraints that truthmaking considerations impose on metaphysical theories. To this end, I reply to Briggs and Forbes (Philos Stud 174(4):927–943, 2017), who argue that certain truthmaking commitments are incurred by a Humean metaphysics and by the Growing-Block theory. First, I argue that Humean Supervenience does not need to endorse a standard version of truthmaker maximalism. This undermines Briggs and Forbes’s conclusion that Humean Supervenience and the Growing-Block theory are incompatible. Second, I argue that the Growing-Block theory does not commit us to any weaker version of truthmaker maximalism, which also undermines Briggs and Forbes’s conclusion. Finally, I point out other reasons to think that any version of truthmaker maximalism is disputable, undermining a fortiori Briggs and Forbes’s conclusion and supporting the moral that metaphysical theories—or at least Humean Supervenience, the Growing-Block theory, and presentism—are little constrained by truthmaking commitments.

Moral alternatives, physical determinism & Frankfurt-style counterexamples

ABSTRACT Agents in Frankfurt-style counterexamples only appear to be responsible insofar as they act willingly in the actual sequence, but would need to be manipulated against their will into forming the relevant intention in the alternative sequence. This difference appears ineliminable and unavoidably morally significant. ‘Neo-Frankfurtians’ concede that the sequences must be physically differentiated, but deny their moral differentiation. In contrast, I explore whether the alternatives could be physically undifferentiated, despite their moral difference. The reason there is an ineliminable moral difference is because there is an ineliminable causal one: The agent’s choice must be caused by his own inclinations in one sequence, but by Black’s manipulation in the other. Whether this causal difference entails a physical one depends on whether we suppose causal relations conform to Humean supervenience. The denial of the latter requires us to either reject any broadly Humean view of causation, or else to suppose that we can individuate events or their qualities independently of the physical facts. If these are coherent possibilities, such examples may show that physically differentiated alternatives are not required for moral responsibility. This could support compatibilism, but only if such examples adequately parallel determinism, and I remain sceptical on this point.

Quantum Mechanics in a Time-Asymmetric Universe: On the Nature of the Initial Quantum State

In a quantum universe with a strong arrow of time, we postulate a low-entropy boundary condition (the past hypothesis, PH) to account for the temporal asymmetry. In this article, I show that the PH also contains enough information to simplify the quantum ontology and define a natural initial condition. First, I introduce ‘density-matrix realism’, the thesis that the quantum state of the universe is objective and impure. This stands in sharp contrast to wave-function realism, the thesis that the quantum state of the universe is objective and pure. Second, I suggest that the PH is sufficient to determine a natural density matrix, which is simple and unique. This is achieved by what I call the ‘initial projection hypothesis’: the initial density matrix of the universe is the (normalized) projection onto the PH-subspace (in the Hilbert space). Third, because the initial quantum state is unique and simple, we have a strong case for the nomological thesis: the initial quantum state of the universe is on a par with laws of nature. This new package of ideas has several interesting implications, including on the harmony between statistical mechanics and quantum mechanics, theoretical unity of the universe and the subsystems, and the alleged conflict between Humean supervenience and quantum entanglement.

Humean supervenience and tripartite entanglement relations

It has been argued that Humean Supervenience (HS) is threatened by the existence of quantum entanglement relations. The most conservative strategy for defending HS is to add the problematic entanglement relations to the supervenience basis, alongside spatiotemporal relations. In this paper, I’m going to argue against this strategy by showing how certain particular cases of tripartite entanglement states – i.e. GHZ states – posit some crucial problems for this amended version of HS. Moreover, I will show that the principle of free recombination – which is strictly linked to HS – is severely undermined if we add entanglement relations to the supervenience basis. I conclude that the conservative move is very unappealing, and therefore the defender of HS should pursue other, more controversial, strategies (e.g. committing to the nomological interpretation of the wave function).

Explanatory dispositionalism

Inspired both by our ordinary understanding of the world and by reflection on science, anti-Humeanism is a growing trend in metaphysics. Anti-Humeans reject the Lewisian doctrine of Humean supervenience that the world is “just one little thing and then another”, and argue instead that dispositions, powers, or capacities provide connection and (some say) activity in nature. But how exactly are we to understand the shared commitment of this anti-Humean movement? I argue that this kind of anti-Humeanism, at its most general level, is to be understood neither as a view about ontology (the existence of certain properties) nor about fundamentality, but rather as a specific claim about what explains what.

How Humean is Bohumianism?

An important part of the influential Humean doctrine in philosophy is the supervenience principle (sometimes referred to as the principle of separability). This principle asserts that the complete state of the world supervenes on the intrinsic properties of its most fundamental components and their spatiotemporal relations (the so-called Humean mosaic). There are well-known arguments in the literature purporting to show that in quantum mechanics the Humean supervenience principle is violated, due to the existence of entangled states. Recently, however, arguments have been presented to the effect that the supervenience principle can be defended in Bohmian mechanics. The key element of this strategy lies in the observation that according to Bohmian mechanics the fundamental facts about particles are facts about their spatial locations, and moreover, for any proper subsystem of the world its state may non-trivially depend on the spatial configuration of the rest of the universe. Thus quantum-mechanical states of subsystems do not represent their intrinsic properties but rather characterize their relations with the environment. In this paper we point out the worry that this Bohmian strategy—known as Bohumianism—saves the letter but not the spirit of the Humean doctrine of supervenience, since it prima facie violates another seemingly important Humean principle, which we call Strong Supervenience and whose denial implies the existence of necessary connections among distinct individuals. We argue that the best defense for Bohumians is to question the fundamental existence of complex physical systems and their states by treating any reference to them as a convenient description of the underlying collection of Bohmian particles. We consider several pros and cons of this strategy.

The package deal account of laws and properties (PDA)

This paper develops an account of the metaphysics of fundamental laws I call “the Package Deal Account (PDA)” that is a descendent of Lewis’ BSA but differs from it in a number of significant ways. It also rejects some elements of the metaphysics in which Lewis develops his BSA. First, Lewis proposed a metaphysical thesis about fundamental properties he calls “Humean Supervenience” (HS) according to which all fundamental properties are instantiated by points or point sized individuals and the only fundamental relations are geometrical spatial and temporal relations between these. While the BSA does not require HS Lewis seems to hope that it is true. In contrast, the PDA is not committed to HS or even to the fundamental arena in which fundamental properties are instantiated possessing geometrical structure and thus is able to accommodate relations and structures found in contemporary physics that apparently conflict with HS. Second, although Lewis’ BSA doesn’t require HS his Humeanism does require that fundamental properties are categorical. In contrast, the PDA allows for the possibility that fundamental properties are individuated in terms of laws and so are not categorical. Third, the PDA expands and develops the criteria for what counts in favor of a candidate system with more attention to the criteria employed by physicists in evaluating proposed theories. Fourth and most importantly, unlike Lewis’ BSA, the PDA does not presuppose metaphysically primitive elite properties/quantities that Lewis calls “perfectly natural” properties/quantities or presuppose a metaphysically preferred language whose terms denote such properties/quantities. It replaces Lewis’ account with an account on which natural properties are not metaphysically prior to the laws but are elements of a package that includes a fundamental arena that plays the role of space-time as well as fundamental laws and properties. By doing so it responds to some epistemological and metaphysical issues that have been raised regarding natural properties and their role in the BSA. In sum, the PDA goes further in explicating the notion of laws in terms of the aims and practices of science especially fundamental physics rather than in terms of prior metaphysics. I begin by reviewing Lewis’ account of perfectly natural properties and his Humean BSA of laws.

On the Very Idea of Distant Correlations

Contemporary debate over laws of nature centers around Humean supervenience, the thesis that everything supervenes on the distribution of non-nomic facts. The key ingredient of this thesis is the idea that nomic-like concepts—law, chance, causation, etc.—are expressible in terms of the regularities of non-nomic facts. Inherent to this idea is the tacit conviction that regularities, “constant conjunctions” of non-nomic facts do supervene on the distribution of non-nomic facts. This paper raises a challenge for this conviction. It will be pointed out that the notion of regularity, understood as statistical correlation, has a necessary conceptual component not clearly identified before—I shall call this the “conjunctive relation” of the correlated events. On the other hand, it will be argued that there exists no unambiguous, non-circular way in which this relation could be determined. In this regard, the notion of correlation is similar to that of distant simultaneity where the necessary conceptual component is the one-way speed of light, whose value doesn’t seem to be determined by matters of (non-nomic) facts.

Why Defend Humean Supervenience?

Humean Supervenience (HS) is a metaphysical model of the world according to which all truths hold in virtue of nothing but the total spatiotemporal distribution of perfectly natural, intrinsic properties. David Lewis and others have worked out many aspects of HS in great detail. A larger motivational question, however, remains unanswered: As Lewis admits, there is strong evidence from fundamental physics that HS is false. What then is the purpose of defending HS? In this paper, we argue that the philosophical merit of HS is largely independent of whether it correctly represents the world’s fundamental structure. In particular, we show that insofar as HS is an apt model of the world’s higher-level structure, it thereby provides a powerful argument for reductive physicalism and explains otherwise opaque inferential relations. Recent criticism of HS on the grounds that it misrepresents fundamental physical reality is, therefore, beside the point.

Structural problems for reductionism

Universal reductionism—the sort of project pursued by Carnap in the Aufbau, Lewis in his campaign on behalf of Humean supervenience, Jackson in From Metaphysics to Ethics, and Chalmers in Constructing the World—aims to reduce everything to some specified base, more or less austere as it may be. In this paper, I identify two constraints that a promising strategy to argue for universal reductionism needs to satisfy: the exhaustion constraint and the chaining constraint. As a case study, I then consider Chalmers’ Constructing the World, in which a priori implication, or “scrutability”, plays the role of reduction. Chalmers first divides up the total vocabulary of our language into different families, and then argues, for each family separately, that truths involving expressions in that family are scrutable from the putative base. He does not systematically address the question whether “cross-family sentences”—sentences involving expressions from more than one family—are scrutable. I shall argue that this lacuna cannot be filled, since scrutability does not allow for the exhaustion constraint and the chaining constraint to be jointly satisfied. I further suggest that Carnap’s account, in which definability plays the role of reduction, has better prospects of meeting these constraints.

What Laws? Which Past?: Meillassoux’s Hyper-Chaos and the Epistemological Limitations of Retro-Causation

Abstract The question of the metaphysical status of the laws of physics has received increased attention in recent years. Perhaps most well-known among this work are David Lewis’s Humean supervenience and Nancy Cartwright’s dispositionalism, both of which reject the classical conception of the laws of physics as necessary and real independent of the objects they govern, arguing instead that what we call laws are shorthand for the regularities of local states of affairs (on Lewis’s account) or the dispositions of objects (on Cartwright’s). The properties of necessity and reality are generally taken to go hand-in-hand when physical laws are concerned; however, this leaves aside the possibility that the laws of physics are independently real (i.e. not just a description of regularities of objects) yet contingent. This paper will explore this third option which is found in the work of Quentin Meillassoux. We will ask: if laws both exist independent of their objects and are contingent, what happens when laws change? Specifically, the possibility of metaphysical retro-causation becomes a live option. This raises both questions of the ontological status of the past as well as our epistemic access to the past after a change in physical laws. Meillassoux’s ontology of hyper-chaos weathers this challenge with its consistency intact; however, it is an open question of whether or not saving the reality of physical laws by sacrificing their necessity is worth the epistemic limits and metaphysical strangeness that it implies.

Radical Pluralism

AbstractHumean Supervenience is the view that (a) there are a plurality of fundamental beings, (b) there are no inexplicable constraints on modal space, and hence the fundamental nature of each such being is independent of those of all the rest and of the fundamental relations in which it stands to the rest, (c) the fundamental beings stand in no fundamental causal or nomic relations, and hence (d) the distribution of any causal or nomic relations in which they do stand globally supervenes on their fundamental natures and the non‐nomic, non‐causal fundamental relations in which they stand. If Humean Supervenience is true, then as A.J. Ayer put it, it's just one damn thing after another. Radical Pluralism is the view that Humean Supervenience is true, and, moreover, that none of the fundamental beings stands in any fundamental relations at all. If Radical Pluralism is true, then, as William James puts it, the world's pieces are held together by nothing more than conjunction: it's just one damn thing and another. I argue that Radical Pluralism is very likely true, conditional upon Humean Supervenience. Any philosopher pluralist enough to be Humean ought to be radically pluralistic.

Lewisian analysis of objective probability: An origin of the undermining futures

David Lewis? interpretation of objective probability has two essential parts: Humean supervenience and Best system of laws. According to his interpretation, probabilities, along with the other nomic phenomena, supervene on the actual facts. Lewis also famously formulated the Principal Principle, which should show the connection between objective and subjective probabilities. However, years later, Hall, Thau and Lewis himself came to conclusion that the principle and Lewis? interpretation of probability are not compatible. The main reason for that is the problem of so called undermining futures: Lewis named the problem ?Big Bad Bug?. A popular way to solve the problem was to change the principal principle. In this article, I will argue that the origin of the problem is not compatibility of the principle and Lewis?s interpretation of probability, but that the problem is in the interpretation itself. Changing the principle, I argue, will not conclusively solve the problem.

Chance, Resiliency, and Humean Supervenience

This paper shows how a particular resiliency-centered approach to chance lends support for two conditions characterizing chance. The first condition says that the present chance of some proposition A conditional on the proposition about some later chance of A should be set equal to that later chance of A. The second condition requires the present chance of some proposition A to be equal to the weighted average of possible later chances of A. I first introduce, motivate, and make precise a resiliency-centered approach to chance whose basic idea is that any chance distribution should be maximally invariant under variation of experimental factors. Second, I show that any present chance distribution that violates the two conditions can be replaced by another present chance distribution that satisfies them and is more resilient under variation of experimental factors. This shows that the two conditions are an essential feature of chances that maximize resiliency. Finally, I explore the relationship between the idea of resilient chances so understood and so-called Humean accounts of chance—one of the most promising recent philosophical accounts of chance.