This paper explores how the Bayesian program benefits from allowing for objective chance as well as subjective degree of belief. It applies David Lewis’s Principal Principle and David Christensen’s principle of informed preference to defend Howard Raiffa’s appeal to preferences between reference lotteries and scaling lotteries to represent degrees of belief. It goes on to outline the role of objective lotteries in an application of rationality axioms equivalent to the existence of a utility assignment to represent preferences in Savage’s famous (...) omelet example of a rational choice problem. An example motivating causal decision theory illustrates the need for representing subjunctive dependencies to do justice to intuitive examples where epistemic and causal independence come apart. We argue to extend Lewis’s account of chance as a guide to epistemic probability to include De Finetti’s convergence results. We explore Diachronic Dutch book arguments as illustrating commitments for treating transitions as learning experiences. Finally, we explore implications for Martingale convergence results for motivating commitment to objective chances. (shrink)

Two types of measures of probabilistic uncertainty are introduced and investigated. Dispersion measures report how diffused the agent’s second-order probability distribution is over the range of first-order probabilities. Robustness measures reflect the extent to which the agent’s assessment of the prior (objective) probability of an event is perturbed by information about whether or not the event actually took place. The properties of both types of measures are investigated. The most obvious type of robustness measure is shown to coincide with one (...) of the major candidates for a dispersion measure, the mean square deviation measure. (shrink)

Humean metaphysics is characterized by a rejection of necessary connections between distinct existences. Dispositionalists claim that there are basic causal powers. The existence of such properties is widely held to be incompatible with the Humean rejection of necessary connections. In this paper I present a novel theory of causal powers that vindicates the dispositionalist claim that causal powers are basic, without embracing brute necessary connections. The key assumptions of the theory are that there are natural types of causal processes, and (...) that manifestations of powers are identified with certain kinds of causal processes. From these assumptions, the modal features of powers are explained in terms of internal relations between powers themselves and the process-types in which powers are manifested. (shrink)

An acceptable empiricist account of laws of nature would havesignificant implications for a number of philosophical projects. For example, such an account may vitiate argumentsthat the fundamental constants of nature are divinelydesigned so that laws produce a life permittinguniverse. On an empiricist account, laws do not produce the universe but are designed by us to systematize theevents of a universe which does in fact contain life; so any ``fine tuning'' of natural law has a naturalistic explanation.But there are problems for (...) the empiricist project. This paper develops a ``perspectival'' version of the Humean bestsystem approach and argues that this version solves the standard problems faced by the empiricist project.Furthermore, the paper argues, this version is best able to answer the proponents of divine design while leaving scientificlaw a suitably objective matter.[I]t is possible tocondense the enormous mass of results to a large extent – that is to find laws which summarize...Richard Feynman It has become fashionable in some circles to argue thatscience is ultimately a sham, that we scientists read order into nature, not out of nature, and that the laws of physicsare our laws, not nature's. I believe this is arrant nonsense. You would be hard-pressed to convince a physicist thatNewton's inverse square law of gravitation is a purely cultural concoction. The laws of physics, I submit, reallyexist in the world out there, and the job of the scientist is to uncover them, not invent them. True, at any giventime, the laws you find in the textbooks are tentative and approximate, but they mirror, albeit imperfectly, a reallyexisting order in the physical world. Of course, many scientists do not recognize that in accepting the reality of anorder in nature-the existence of laws `out there' – they are adopting a theological world view. P. C. W. Davies. (shrink)

This paper discusses some serious difficulties for what we shall call the standard account of various kinds of relative necessity, according to which any given kind of relative necessity may be defined by a strict conditional - necessarily, if C then p - where C is a suitable constant proposition, such as a conjunction of physical laws. We argue, with the help of Humberstone, that the standard account has several unpalatable consequences. We argue that Humberstone’s alternative account has certain disadvantages, (...) and offer another - considerably simpler - solution. (shrink)

August 16, 1997 David Lewis2 has long defended an account of scientific law acceptable even to an empiricist with significant metaphysical scruples. On this account, the laws are defined to be the consequences of the best system for axiomitizing all occurrent fact. Here "best system" means the set of sentences which yields the best combination of strength of descriptive content 3 with simplicity of exposition. And occurrent facts, the facts to be systematized, are roughly the particular facts about a localized (...) space-time region that are non-modal, non-dispositional, and non-causal. Scientists providing or attempting to provide laws are plausibly seen as giving general principles that unify a body of data. Thus they organize or systematize the arrangement of occurrences. For this reason, Lewis's account has the important merits of providing contact with actual scientific practice while making sense of the standard philosophical conception that laws should be general but more than mere accidental generalizations. However, Lewis has long known about a potential problem with this account, a problem involving chance and credence.4 In a recent series of articles he, Michael Thau, and Ned Hall have developed a new formulation of the relationship between chance and credence which solves the problem. However, I will argue that these articles leave untouched and even exacerbate a closely related and more fundamental problem with the best system account, the problem of nomic necessity. Laws are supposed to be more than true; in some sense they must be true. Yet a principle's membership in the best systematization for one world seems to say nothing about its necessity, i.e., its truth at other worlds. I close by briefly describing how an alternative empiricist account may remove both problems. (shrink)

Rachel Briggs’ critique of “antirealist” accounts of scientific law— including my own perspectivalist best-system account—is part of a project meant to show that Humean conceptions of scientific law are more problematic than has been commonly realized. Indeed, her argument provides a new challenge to the Humean, a thoroughly epistemic version of David Lewis’ “big, bad bug” for Humeanism. Still, I will argue, the antirealist (perspectivalist and expressivist) accounts she criticizes have the resources to withstand the challenge and come out stronger (...) for it. Attention to epistemic possibilities, I argue, shows a number of advantages to a perspectivalist account of scientific law. (shrink)

Objective chance, or the “big bad bug” of David Lewis's account of Humean Supervenience forces, as is well known, is a modification of the Principal Principle. Here, I argue that standard assumptions regarding conditional probabilities entail several puzzling consequences for Lewis's New Principle, namely, an apparent requirement to account for the chance of a theory of chance. These problems, I argue, cannot be adequately answered within the received framework, and so I suggest that an interpretation of conditional probabilities in terms (...) of Alan Hájek's recent work might go some distance toward their resolution. (shrink)

We call attention to different formulations of how physical laws relate to what is physically possible in the philosophical literature, and argue that it may be the case that determinism fails under one formulation but reigns under the other. Whether this is so depends on our view on the nature of laws, and may also depend on the inter-theoretical relationships among our best physical theories, or so shall we argue.

Dorr et al. present a case that poses a challenge for a number of plausible principles about knowledge and objective chance. Implicit in their discussion is an interesting new argument against KK, the principle that anyone who knows p is in a position to know that they know p. We bring out this argument, and investigate possible responses for defenders of KK, establishing new connections between KK and various knowledge-chance principles.

Some propositions are true, and it is true that some propositions are true. Each of these facts looks like an impeccable ground of the other. But they cannot both ground each other, since grounding is asymmetric. This paper explores two new diagnoses of this much discussed puzzle. The tools of higher-order logic are used to show how both diagnoses can be fleshed out into strong and consistent theories of grounding. These theories of grounding in turn demand new theories of the (...) granularity of propositions, properties, and relations. Even those who are uninterested in grounding should take seriously these pictures of reality’s logical structure, which are in many ways reminiscent of Russell’s and Wittgenstein’s logical atomism. (shrink)

The intuitive distinction between natural and unnatural properties (e.g., green vs. grue) informs our theorizing not only in fundamental physics, but also in non-fundamental domains. This paper develops a reductive account of this broad notion of naturalness that covers non-fundamental properties: for a property to be natural, I propose, is for it to figure in a law of nature. After motivating the account, I defend it from a potential circularity charge. I argue that a suitably broad notion of lawhood can (...) be defined independently of naturalness, if we help ourselves to the notion of a fundamental physical property. I end by showing how the notions of naturalness and lawhood that my account delivers help illuminate a number of other important philosophical notions, like causation, reference/meaning, and rational induction. (shrink)

The central claim of this paper is that the Aristotelian metaphysics of objects is incompatible with physicalism. This includes the contemporary variant of Aristotelianism I call ‘sortalism’. The core reason is that an object’s identity as an instance of a (natural) kind, as well as its consequent persistence conditions, is neither physically fundamental nor determined by what is physically fundamental. The argument for the latter appeals to what is commonly known as ‘the grounding problem’; in particular I argue that the (...) physicalist has no solution, and this requires that the physicalist jettison the traditional concept of objects having kind-specific identity and persistence conditions. (shrink)

I argue that there are non-trivial objective chances (that is, objective chances other than 0 and 1) even in deterministic worlds. The argument is straightforward. I observe that there are probabilistic special scientific laws even in deterministic worlds. These laws project non-trivial probabilities for the events that they concern. And these probabilities play the chance role and so should be regarded as chances as opposed, for example, to epistemic probabilities or credences. The supposition of non-trivial deterministic chances might seem to (...) land us in contradiction. The fundamental laws of deterministic worlds project trivial probabilities for the very same events that are assigned non-trivial probabilities by the special scientific laws. I argue that any appearance of tension is dissolved by recognition of the level-relativity of chances. There is therefore no obstacle to accepting non-trivial chance-role-playing deterministic probabilities as genuine chances. (shrink)

Though almost forty years have elapsed since its first publication, it is a testament to the philosophical acumen of its author that 'The Matter of Chance' contains much that is of continued interest to the philosopher of science. Mellor advances a sophisticated propensity theory of chance, arguing that this theory makes better sense than its rivals (in particular subjectivist, frequentist, logical and classical theories) of ‘what professional usage shows to be thought true of chance’ (p. xi) – in particular ‘that (...) chance is objective, empirical and not relational, and that it applies to the single case’ (ibid.). The book is short and dense, with the serious philosophical content delivered thick and fast. There is little by way of road-mapping or summarising to assist the reader: the introduction is hardly expansive and the concluding paragraph positively perfunctory. The result is that the book is often difficult going, and the reader is made to work hard to ensure correct understanding of the views expressed. On the other hand, the author’s avoidance of unnecessary use of formalism and jargon ensures that the book is still reasonably accessible. In the following, I shall first summarise the key features of Mellor’s propensity theory, and then offer a few critical remarks. (shrink)

According to David Lewis’s Modal Realism, other possible worlds really exist as concrete, spatiotemporal systems, and every way that a world could be is a way that some world is. To establish this plenitude of concrete possible worlds, Lewis presents his ‘principle of recombination,’ which is meant to guarantee that there exists a possible world, or part of a possible world, for every possibility. Jessica Wilson has recently argued that Lewis’s principle of recombination fails to generate enough worlds to account (...) for the plenitude of possibilities. Namely, Wilson argues that the principle of recombination cannot account for the possibility of spatially overlapping but distinct fundamental entities, as well as certain macroscopic entities. In this paper, I will defend Lewis’s principle of recombination against these charges, arguing that Wilson’s objections overlook features of Lewisian metaphysics that can solve the problems at hand. (shrink)

What grounds facts of ground? Some metaphysicians invoke fundamental grounding laws to answer this question. These are general principles that link grounded facts to their grounds. The main business of this paper is to advance the debate about the metaphysics of grounding laws by exploring the prospects of a plausible yet underexplored minimalist account, one which is structurally analogous to a familiar Humean conception of natural laws. In the positive part of this paper, I articulate such a novel view and (...) argue for its merits. The minimalist account shuns essences and takes laws to be unmysterious elite regularities. Therefore, it is a promising alternative for theorists of ground who spurn the acceptance of essentialism about the grounding laws but think that these are needed in our theorizing. In the negative part, I argue that widely accepted principles of ground, coupled with the tenets of minimalism, jeopardize the fundamentality of the grounding laws. I discuss two immediately available and prima facie appealing strategies to evade this threat. However, I show that both have undesirable theoretical costs. I conclude by casting doubts on whether the benefits of a minimalist account of fundamental grounding laws outweigh such costs. (shrink)

Does the brain behave indeterministically? I argue that accounting for ion channels, key functional units in the brain, requires indeterministic models. These models are probabilistic, so the brain does behave indeterministically in a weak sense. I explore the implications of this point for a stronger sense of indeterminism. Ultimately I argue that it is not possible, either empirically or through philosophical argument, to show that the brain is indeterministic in that stronger sense.

I start by way of clarifying briefly the problem of special divine intervention. Once this is done, I argue that laws of nature are generalizations that derive from the dispositional behaviour of natural kinds. Based on this conception of laws of nature I provide a metaphysical model according to which God can realize acts of special divine providence by way of temporarily changing the dispositions of natural entities. I show that this model does not contradict scientific practice and is consistent (...) with the assumption that the physical realm is causally closed. I then argue that prima facie any putative candidate for an act of God could also be seen as a random event or as indicating that there is something wrong with our formulation of the corresponding law of nature. While there is no sufficient philosophical or scientific reason to prefer one of these models, I argue that there are sufficient and legitimate theological reasons to endorse a framework in which at least the obtaining of some anomic states of affairs is seen as the effect of special divine intervention. Doing so, theology has the hermeneutic resources to uncover a dimension of meaningful reality, which without faith could not be seen. (shrink)

A common type of argument against the existence of God is to argue that certain essential features associated with the existence of God are inconsistent with certain other features to be found in the actual world. for an analysis of the different ways to deploy the term “God” in philosophical and theological discourse and for an analysis of the logical form of arguments for and against the existence of God.) A recent example of this type of argument against the existence (...) of God is based on the assumption that there are random processes or chancy states of affairs in the actual world that contradict God being absolute sovereign over his creation: Chancy states of affairs are said to entail a denial of divine providence or omniscience. argues that “classical Big Bang cosmology is inconsistent with theism due to the unpredictable nature of the Big Bang singularity.”) More often than not, however, this apparent conflict is formulated only intuitively and lacks sufficient conceptual clarification of the crucial terms involved. As a consequence, it is seldom clear where the conflict really lies. In what follows, I first provide a brief analysis of chance and randomness before I turn to cosmological and evolutionary arguments against the existence of God that in some way or other are based on chance and randomness. I end by way of comparing three popular conceptions of God as regards their ability to deal with God’s relation to a world of chance and randomness. Neither classical theism, nor open theism, nor indeed process panentheism has difficulties in accounting for God’s relation to a world of chance and randomness. (shrink)

Epistemological accounts that make use of a safety condition on knowledge, historically, face serious problems regarding beliefs that are necessarily true. This is because necessary truths are true in all possible worlds, so such beliefs can be safe even when the bases for the beliefs are epistemically problematic. The existence of such problematically safe beliefs would undermine a major motivation for the condition itself: the ability to evaluate how well a belief tracks the truth. In this paper, we’ll argue that (...) incorporating impossible worlds into the evaluation of beliefs solves this problem, but only if the relevant account of impossible worlds entails that many impossible worlds are incredibly similar to the actual world. Further, we’ll argue that, as a result of including impossible worlds, some philosophical beliefs are unsafe, and many more are potentially unsafe. But, we argue, even if this is the case, we can still make philosophical progress. (shrink)

The externalist says that your evidence could fail to tell you what evidence you do or not do have. In that case, it could be rational for you to be uncertain about what your evidence is. This is a kind of uncertainty which orthodox Bayesian epistemology has difficulty modeling. For, if externalism is correct, then the orthodox Bayesian learning norms of conditionalization and reflection are inconsistent with each other. I recommend that an externalist Bayesian reject conditionalization. In its stead, I (...) provide a new theory of rational learning for the externalist. I defend this theory by arguing that its advice will be followed by anyone whose learning dispositions maximize expected accuracy. I then explore some of this theory’s consequences for the rationality of epistemic akrasia, peer disagreement, undercutting defeat, and uncertain evidence. (shrink)

Consider two epistemic experts—for concreteness, let them be two weather forecasters. Suppose that you aren’t certain that they will issue identical forecasts, and you would like to proportion your degrees of belief to theirs in the following way: first, conditional on either’s forecast of rain being x, you’d like your own degree of belief in rain to be x. Secondly, conditional on them issuing different forecasts of rain, you’d like your own degree of belief in rain to be some weighted (...) average of the forecast of each. Finally, you’d like your degrees of belief to be given by an orthodox probability measure. Moderate ambitions, all. But you can’t always get what you want. (shrink)

A norm of local expert deference says that your credence in an arbitrary proposition A, given that the expert's probability for A is n, should be n. A norm of global expert deference says that your credence in A, given that the expert's entire probability function is E, should be E(A). Gaifman (1988) taught us that these two norms are not equivalent. Stalnaker (2019) conjectures that Gaifman's example is "a loophole". Here, I substantiate Stalnaker's suspicions by providing characterisation theorems which (...) tell us precisely when the norms give different advice. They tell us that, in a good sense, Gaifman's example is the only case where the two norms differ. I suggest that the lesson of the theorems is that Bayesian epistemologists need not concern themselves with the differences between these two kinds of norms. While they are not strictly speaking equivalent, they are equivalent for all philosophical purposes. (shrink)

Principles of chance deference face two kinds of problems. In the first place, they face difficulties with a priori knowable contingencies. In the second place, they face difficulties in cases where you've lost track of the time. I provide a principle of chance deference which handles these problem cases. This principle has a surprising consequence for Adam Elga's Sleeping Beauty Puzzle.

I present an account of deterministic chance which builds upon the physico-mathematical approach to theorizing about deterministic chance known as 'the method of arbitrary functions'. This approach promisingly yields deterministic probabilities which align with what we take the chances to be---it tells us that there is approximately a 1/2 probability of a spun roulette wheel stopping on black, and approximately a 1/2 probability of a flipped coin landing heads up---but it requires some probabilistic materials to work with. I contend that (...) the right probabilistic materials are found in reasonable initial credence distributions. I note that, with some normative assumptions, the resulting account entails that deterministic chances obey a variant of Lewis's 'principal principle'. I additionally argue that deterministic chances, so understood, are capable of explaining long-run frequencies. (shrink)

There is an inconsistency between the access we have to our conscious lives and the Humean thesis of causal generalism. This was first drawn attention to by John Hawthorne, whose argument withstands a number of objections. Nevertheless, it has weaknessess. The first premise must be weakened if Humeans are to be compelled to accept it, and consequently, the second premise will have to be stronger to retain validity. I shore up the case against Humeanism by providing revised premises along with (...) new defences of them. I show why this also provides a lesson for non-Humeans about the epistemology of causal relations. (shrink)

Lewis’s original Best Systems Account of laws was not motivated much by pragmatics. But recent commentary on his general approach to laws has taken a ‘pragmatic turn’. This was initiated by Hall’s defence against the charge of ‘ratbag idealism’ which maintained that best systems accounts should be admired rather than criticised for the inherent pragmatism behind their choice of desiderata for what counts as ‘best’. Emboldened by Hall’s pragmatic turn, recent commentators have proposed the addition of pragmatically motivated desiderata to (...) complement or replace the canonical desiderata of strength and simplicity. This, they hope, will allow their revisionary BSAs to respond better to various counterexamples against the original account. While the pragmatic turn itself is well taken, here I problematise these revisionary approaches. First, there are reasonable responses to the counterexamples from within the canonical BSA. Second, while actual laws may satisfy the newly proposed desiderata, there are reasons to think these desiderata cannot be constitutive of laws. By comparison, the canonical desiderata appear to be relevant to explaining why and when the revisionary desiderata will reflect pragmatic features of the laws and better reflect the motives behind practitioners of fundamental physics. (shrink)

Classical statistical mechanics posits probabilities for various events to occur, and these probabilities seem to be objective chances. This does not seem to sit well with the fact that the theory’s time evolution is deterministic. We argue that the tension between the two is only apparent. We present a theory of Humean objective chance and show that chances thus understood are compatible with underlying determinism and provide an interpretation of the probabilities we find in Boltzmannian statistical mechanics.

There is widespread belief in a tension between quantum theory and special relativity, motivated by the idea that quantum theory violates J. S. Bell’s criterion of local causality, which is meant to implement the causal structure of relativistic space-time. This paper argues that if one takes the essential intuitive idea behind local causality to be that probabilities in a locally causal theory depend only on what occurs in the backward light cone and if one regards objective probability as what imposes (...) constraints on rational credence along the lines of David Lewis’ Principal Principle, then one arrives at the view that whether or not Bell’s criterion holds is irrelevant for whether or not local causality holds. The assumptions on which this argument rests are highlighted, and those that may seem controversial are motivated. (shrink)

GRW Theory postulates a stochastic mechanism assuring that every so often the wave function of a quantum system is `hit', which leaves it in a localised state. How are we to interpret the probabilities built into this mechanism? GRW theory is a firmly realist proposal and it is therefore clear that these probabilities are objective probabilities (i.e. chances). A discussion of the major theories of chance leads us to the conclusion that GRW probabilities can be understood only as either single (...) case propensities or Humean objective chances. Although single case propensities have some intuitive appeal in the context of GRW theory, on balance it seems that Humean objective chances are preferable on conceptual grounds because single case propensities suffer from various well know problems such as unlimited frequency tolerance and lack of a rationalisation of the principal principle. (shrink)

Can the desire for efficiently systematised theories in science be explained from within a powers metaphysics? It is plausible that the traditional ‘Powers Theory of Laws’, endorsed by many friends of powers, does not alone provide such an explanation. This has led a number of recent authors to argue that a ‘Powers Best System Account’ of laws would be a preferable alternative. This account borrows a method for determining laws from the Humean and applies it to a reality of powers. (...) Here I claim, to the contrary, that this account is both internally unworkable and, anyway, completely undermotivated when compared with the traditional view. Apart from some brief suggestions for alternative accounts, I’ll conclude that the powers theorist still has their work cut out to explain systematising in science. (shrink)

The paper discusses objections against non-hidden variable versions of the epistemic conception of quantum states—the view that quantum states do not describe the properties of quantum systems but reflect, in some way to be specified, the epistemic conditions of agents assigning them. In the first half of the paper, the main motivation for the epistemic conception of quantum states is sketched, and a version of it is outlined, which combines ideas from an earlier study of it with elements of Richard (...) Healey's recent pragmatist interpretation of quantum theory. In the second half, various objections against epistemic accounts of quantum states are discussed in detail, which are based on criticisms found in the literature. Possible answers by the version outlined here are compared with answers from the quantum Bayesian point of view, which is at present the most discussed version of the epistemic conception of quantum states. (shrink)

Consider a gas that is adiabatically isolated from its environment and confined to the left half of a container. Then remove the wall separating the two parts. The gas will immediately start spreading and soon be evenly distributed over the entire available space. The gas has approached equilibrium. Thermodynamics (TD) characterizes this process in terms of an increase of thermodynamic entropy, which attains its maximum value at equilibrium. The second law of thermodynamics captures the irreversibility of this process by positing (...) that in an isolated system such as the gas entropy cannot decrease. The aim of statistical mechanics (SM) is to explain the behavior of the gas and, in particular, its conformity with the second law in terms of the dynamical laws governing the individual molecules of which the gas is made up. In what follows these laws are assumed to be the ones of Hamiltonian classical mechanics. We should not, however, ask for an explanation of the second law literally construed. This law is a universal law and as such cannot be explained by a statistical theory. But this is not a problem because we.. (shrink)

Both realist and anti-realist accounts of natural kinds possess prima facie virtues: realists can straightforwardly make sense of the apparent objectivity of the natural kinds, and anti-realists, their knowability. This paper formulates a properly anti-realist account designed to capture both merits. In particular, it recommends understanding natural kinds as ‘categorical bottlenecks,’ those categories that not only best serve us, with our idiosyncratic aims and cognitive capacities, but also those of a wide range of alternative agents. By endorsing an ultimately subjective (...) categorical principle, this view sidesteps epistemological difficulties facing realist views. Yet, it nevertheless identifies natural kinds that are fairly, though not completely, stance-independent or objective. (shrink)

In this paper I offer an argument for the view that every body of evidence rationalizes exactly one doxastic attitude to each proposition. This is the uniqueness thesis. I do this by identifying a family of explanatory demands facing permissivists, those who deny the uniqueness thesis. Permissivists have traditionally motivated their view by attempting to identify counterexamples to the uniqueness thesis. But they have not developed a more general account of when permissive cases arise, and why. Permissivists cannot explain why (...) permissive cases are permissive, or how permissive they are. The paper contains three sections. First, I identify the explanatory demands facing the permissivist. Second, I survey a few existing proposals in the literature for how these explanatory demands might be answered, and argue that they fail. In the third section, I consider how permissivists might “soften” these explanatory demands, by holding that the permissible range of attitudes has vague borders, or that we do not know where its borders lie. I argue against both options. To do this, I present a general argument that there cannot be vague deontic facts, by appealing to a dominance principle and basic principles of deontic logic. If there are no deontic facts, then the permissible range of attitudes could not have vague borders, so the explanatory demands facing the permissivist remain unanswered. (shrink)

considers what I call free-floating chances—objective chances that obtain at a given time despite the fact that their values are not determined by the laws of nature together with the full history of non-chancy facts up to that time. I offer an intuitive example of this phenomenon, and use it to argue that free-floating chances are indeed possible. Their possibility violates three quite widely held principles about chances: the lawful magnitude principle, the principle that chances evolve by conditionalization and a (...) version of David Lewis' principal principle. I argue that we should reject common formulations of each of these principles, though I offer revised understandings of each which retain much of the intuitive attractiveness of the originals and are consistent with the possibility of free-floating chances. I conclude by arguing that, while considerations of free-floating chances are important, they will not sustain the extravagant conclusions Lange attempts to draw from them. Introduction First- and Higher-Order Chances Free-Floating Chances Support for the Intuitive Assessment Three Principles Violated What to do? COND as a Default Hypothesis A More Principled Principal Principle Conclusion. (shrink)

This paper is a response to Lewis’ ‘Humean Supervenience Debugged’ . Lewis was in the business of defending Humean Supervenience, and the project seemed successful until the case of chance. Lewis thus originally named chance the ‘big bad bug’ for Humean Supervenience until the aforementioned paper in which he claims victory. Here I argue that he was unsuccessful and that Humean Supervenience remains bugged by chance. I will show how this bug remains due to a misdiagnosis of where the problem (...) lies with regard to undermining. First, I define Humean Supervenience and chance, and state the bug in its original form, then secondly I describe Lewis’ attempt to remove the bug. Thirdly, I explain why the bug persists, despite Lewis’ efforts, and show the real source of the undermining problem to be due to the circularity of Humean Supervenient style accounts of chance. Finally I describe the situation this leaves chance in, and show how the incompatibility of chance and Humean Supervenience is evidence for the nonexistence of chance. I conclude that it is the circularity of the formation of Humean Supervenient laws of chance which continue to bug Humean Supervenience, leaving it untenable and resulting in little chance for chance. (shrink)

If the laws of nature are as the Humean believes, it is an unexplained cosmic coincidence that the actual Humean mosaic is as extremely regular as it is. This is a strong and well-known objection to the Humean account of laws. Yet, as reasonable as this objection may seem, it is nowadays sometimes dismissed. The reason: its unjustified implicit assignment of equiprobability to each possible Humean mosaic; that is, its assumption of the principle of indifference, which has been attacked on (...) many grounds ever since it was first proposed. In place of equiprobability, recent formal models represent the doxastic state of total ignorance as suspension of judgment. In this paper I revisit the cosmic coincidence objection to Humean laws by assessing which doxastic state we should endorse. By focusing on specific features of our scenario I conclude that suspending judgment results in an unnecessarily weak doxastic state. First, I point out that recent literature in epistemology has provided independent justifications of the principle of indifference. Second, given that the argument is framed within a Humean metaphysics, it turns out that we are warranted to appeal to these justifications and assign a uniform and additive credence distribution among Humean mosaics. This leads us to conclude that, contrary to widespread opinion, we should not dismiss the cosmic coincidence objection to the Humean account of laws. (shrink)

Special science generalizations admit of exceptions. Among the class of non-exceptionless special science generalizations, I distinguish minutis rectis generalizations from the more familiar category of ceteris paribus generalizations. I argue that the challenges involved in showing that mr generalizations can play the law role are underappreciated, and quite different from those involved in showing that cp generalizations can do so. I outline a strategy for meeting the challenges posed by mr generalizations.

This paper provides a prospectus for a new way of thinking about the wavefunction of the universe: a Ψ-epistemic quantum cosmology. We present a proposal that, if successfully implemented, would resolve the cosmological measurement problem and simultaneously allow us to think sensibly about probability and evolution in quantum cosmology. Our analysis draws upon recent work on the problem of time in quantum gravity and causally symmet- ric local hidden variable theories. Our conclusion weighs the strengths and weaknesses of the approach (...) and points towards paths for future development. (shrink)

The article sets out a primitive ontology of the natural world in terms of primitive stuff—that is, stuff that has as such no physical properties at all—but that is not a bare substratum either, being individuated by metrical relations. We focus on quantum physics and employ identity-based Bohmian mechanics to illustrate this view, but point out that it applies all over physics. Properties then enter into the picture exclusively through the role that they play for the dynamics of the primitive (...) stuff. We show that such properties can be local, as well as holistic, and discuss two metaphysical options to conceive them, namely, Humeanism and modal realism in the guise of dispositionalism. 1 Introduction2 Primitive Ontology: Primitive Stuff3 The Physics of Matter as Primitive Stuff4 The Humean Best System Analysis of the Dynamical Variables5 Modal Realism about the Dynamical Variables6 Conclusion. (shrink)

This paper seeks to answer the following question: What is a minimal set of entities that form an ontology of the natural world, given our well-established physical theories? The proposal is that the following two axioms are sufficient to obtain such a minimalist ontology: There are distance relations that individuate simple objects, namely matter points. The matter points are permanent, with the distances between them changing. I sketch out how one can obtain our well-established physical theories on the basis of (...) just these two axioms. The argument for minimalism in ontology then is that it yields all the explanations that one can reasonably demand in science and philosophy, while avoiding the drawbacks that come with a richer ontology. (shrink)

This paper seeks to answer the following question: What is a minimal set of entities that form an ontology of the natural world, given our well-established physical theories? The proposal is that the following two axioms are sufficient to obtain such a minimalist ontology: (1) There are distance relations that individuate simple objects, namely matter points. (2) The matter points are permanent, with the distances between them changing. I sketch out how one can obtain our well-established physical theories on the (...) basis of just these two axioms. The argument for minimalism in ontology then is that it yields all the explanations that one can reasonably demand in science and philosophy, while avoiding the drawbacks that come with a richer ontology. (shrink)

In this paper, we put forward an alternative interpretation of time-reversal symmetry in philosophy of physics: Humean time-reversal symmetry. According to it, time-reversal symmetry is understood as a heuristic, epistemic virtue of the best system, not as a property of the Humean mosaic. One of the consequences of this view is that one of the main arguments against a primitive direction of time is rendered harmless, which paves the way for primitivism about the direction of time.

I present an argument for the view that laws ground their instances. I then outline two important consequences that follow if we accept the conclusion of this argument. First, the claim that laws ground their instances threatens to undermine a prominent recent attempt to make sense of the explanatory power of Humean laws by distinguishing between metaphysical and scientific explanation. And second, the claim that laws ground their instances gives rise to a novel argument against the view that grounding relations (...) are metaphysically necessary. (shrink)

Two options are ‘incommensurate’ when neither is better than the other, but they are not equally good. Typically, we will say that one option is better in some ways, and the other in others, but neither is better ‘all things considered’. It is tempting to think that incommensurability is vagueness—that it is (perhaps) indeterminate which is better—but this ‘vagueness view’ of incommensurability has not proven popular. I set out the vagueness view and its implications in more detail, and argue that (...) it can explain most of the puzzling features of incommensurability. This argument proceeds without appeal to John Broome’s ‘collapsing principle’. (shrink)

Philosophical Perspectives, Volume 35, Issue 1, Page 170-188, December 2021.

According to David Lewis’s Principal Principle, our beliefs about the objective chances of outcomes determine our rational credences in those outcomes. Lewis influentially argues that any adequate metaphysics of objective chance must explain why the Principal Principle holds. Since no theory of chance is widely agreed to have met this burden, I suggest we change tack. On the view I develop, a central aspect of the Principal Principle holds not because of what objective chances are but rather because of the (...) explanatory role that objective chances play for the rational agents who believe in them. (shrink)