Ezra Rubenstein

How do conjunctions relate to their conjuncts? How, for example, does relate to the propositions and? This paper explores the unorthodox answer that conjunctions are identical to their conjuncts: throwing grammar to the wind, just 'is' the propositions and. I suggest two ways of motivating the view (§1), present my preferred formulation of it (§2), discuss some objections (§3), point out some connections to neighboring issues (§4), and finally, consider how it may be extended to a more comprehensive view of logical complexity (§5).

According to contemporary consensus, physical probabilities may be “non-uniform”: they need not correspond to a uniform measure over the space of physically possible worlds. Against consensus, I argue that only uniform probabilities connect robustly to long-run frequencies. Suppose, for example, that a uniform measure assigns a probability of x to a coin landing Heads on any given toss (independently of the outcomes on other tosses). Then, in almost all physically possible worlds containing many tosses, the frequency of Heads outcomes approximates x. Thus, if the physical probability of Heads is not x, the frequency deviates from this probability in almost all physically possible worlds. But this would undermine the robust connection between long-run frequencies and physical probabilities. Conclusion: the uniform measure assigns the correct physical probability to Heads outcomes! This paper makes the argument rigorous and general, and evaluates its significance.

It is well-known that naturalistic dualism faces the ‘T-shirt problem’: it seems to require that the connections between physical and phenomenal truths are somehow covered by compact physical-phenomenal laws. This paper is a detailed exploration of a parallel issue that arises for grounding physicalism –– the view that phenomenal truths are grounded in, but not reducible to, physical truths. It presents four possible responses on behalf of grounding physicalists, and argues that none is satisfactory.

Some theories are alleged to be implausible because they are committed to systematic ‘overdetermination’. In response, some authors defend ‘compatibilism’: the view that the putative overdetermination is benign, like other unproblematic cases of a single effect having many sufficient causes. The literature has tended to focus on the following question: which relations between sufficient causes of a single effect ensure that problematic overdetermination is avoided? This paper argues that several widely endorsed answers to this question are subject to counterexample. It then proposes a diagnosis of this failure: the standard answers neglect what really matters––how the causes are connected to their shared effect. In particular, overdetermination is avoided when there are no independent causal connections.

According to generalism, the world is fundamentally general –– ultimately, there are no individuals. I distinguish two versions of this view. ‘Permissive generalism’ holds that facts involving individuals are non-basic: they are generated by purely general basic facts. I argue that permissive generalists will struggle to provide suitably systematic and non-arbitrary explanations for facts involving individuals. These problems are avoided by switching to ‘strict generalism’: the view that truths about individuals are non-perspicuous, and reduce to purely general perspicuous truths. I illustrate this alternative approach by proposing a metaphysical semantics for individualist truths in general terms. This serves both as a recommendation to generalists and, more broadly, as a case study in two different approaches to metaphysical explanation: one centered on generation, the other on reduction.

Explanatory metaphysics aspires to explain the less fundamental in terms of the more fundamental. But we should recognize two importantly different approaches to this task. According to the generation approach, more basic features of reality generate (or give rise to) less basic features. According to the reduction approach, less perspicuous ways of representing reality reduce to (or collapse into) more perspicuous ways of representing reality. The main goals of this paper are to present the core differences between the two approaches (§2), to demonstrate the distinction's significance (§3), to provide some resources for adjudicating between the approaches (§4), and to argue that the project of explanatory metaphysics needs both (§5).

A much-discussed idea in the causation literature is that it is preferable to invoke causes which are proportional to—neither too general nor too specific for—the effect. This article presents various ways of understanding this idea. In what sense are such causal claims ‘preferable’? And what is it for one event to be ‘proportional’ to another? In a companion article, ‘Proportionality in Causation, Part II: Applications and Challenges’, I discuss the principal applications of the resulting theories of proportionality, and the challenges they face.

Proportionality—the idea that causes are neither too general nor too specific for their effects—seems to recommend implausibly disjunctive causes (McGrath, 1998 ; Shapiro & Sober, 2012 ; Franklin-Hall, 2016 ). I argue that this problem should be avoided by appeal to the notion of cohesion. I propose an account of cohesion in terms of the similarity structure of property-spaces, argue that it is not objectionably mysterious, and that alternative approaches—based on naturalness, interventionism, and contrastivism—are inadequate without appeal to it. In an appendix, I show how my proposal can be perspicuously formalized by adapting structural equation models.

According to a radical account of quantum metaphysics that I label ‘high-dimensionalism’, ordinary objects are the ‘shadows’ of high-dimensional fundamental ontology. Critics—especially Maudlin —allege that high-dimensionalism cannot provide a satisfactory explanation of the manifest image. In this paper, I examine the two main ideas behind these criticisms: that high-dimensionalist connections between fundamental and non-fundamental are 1) inscrutable, and 2) arbitrary. In response to the first, I argue that there is no metaphysically significant contrast regarding the scrutability of low- and high-dimensionalist connections. In response to the second, I argue that the arbitrariness of high-dimensionalist connections has been overstated, and what arbitrariness there is afflicts low-dimensionalist connections too. Thus, the debate should not be focused on whether high-dimensionalism can provide a satisfactory explanation of the manifest image—as it has been in recent literature—but rather on the broader question of whether there is good all-things-considered reason to prefer low-dimensionalist theories.

What grounds the facts about what is identical to/distinct from what? A natural answer is: the facts about what exists. Despite its prima facie appeal, this view has received surprisingly little attention in the literature. Moreover, those who have discussed it have been inclined to reject it because of the following important challenge: why should the existence of some individuals ground their identity in some cases and their distinctness in others? (Burgess 2012, Shumener 2020b). This paper offers a sustained defense of the view. The first half provides some positive motivations in terms of other natural principles involving ground. The second half considers various ways of distilling the challenge into a precise objection to the view, and argues that none of the resulting objections proves persuasive.