One conception of the Principle of Sufficient Reason maintains that every fact is metaphysically explained. There are different ways to challenge this version of the PSR; one type of challenge involves pinpointing a specific set of facts that resist metaphysical explanation. Certain identity and distinctness facts seem to constitute such a set. For example, we can imagine a scenario in which we have two qualitatively identical spheres, Castor and Pollux. Castor is distinct from Pollux but it is unclear what could (...) metaphysically explain this distinctness fact. In this paper, I argue that we should not treat identity and distinctness facts as metaphysically fundamental. As such, identity and distinctness facts do not challenge the PSR. We can metaphysically explain them. (shrink)

As Descartes famously pointed out in the Second Meditation, the thought that someone is thinking is true anytime anyone thinks it. Furthermore, thinking it makes it true. Conversely, anytime anyone thinks that it is not the case that someone is thinking, this thought is false, and thinking it makes it false.l will argue that the propositions ‘There is at least one true normative proposition’ and ‘There are no true normative propositions’ have very similar properties. The proposition ‘There is at least (...) one true normative proposition,’ like the proposition ‘Someone is thinking,’ is true anytime anyone believes it, and, in an important sense, it is made true by someone's believing it. Conversely, anytime anyone believes that there are no true normative propositions, the proposition he believes is false and his believing it makes it false. (shrink)

This paper argues that the semantic facts about ‘because’ are best explained via a metaphorical treatment of metaphysical explanation that treats causal explanation as explanation par excellence. Along the way, it defends a commitment to a unified causal sense of ‘because’ and offers a proprietary explanation of grounding skepticism. With the causal metaphor account of metaphysical explanation on the table, an extended discussion of the relationship between conceptual structure and metaphysics ends with a suggestion that the semantic facts about ‘because’ (...) tell against grounding-causation unity. (shrink)

This paper presents evidence that ‘because’ is importantly ambiguous between two closely related senses covering what are usually called causal explanations, on the one hand, and grounding or metaphysical explanations, on the other hand. To this end, it introduces the lexical categories of monosemy, polysemy and homonymy; describes a test for polysemy; and discusses the results of the test when applied to ‘because’. It also shows how to understand so-called hybrid explanations in light of the semantic facts established by the (...) analysis. (shrink)

Classic inductive skepticism–the epistemological claim that we have no good reason to believe that the unobserved resembles the observed–is plausibly everyone’s lot, whether or not they embrace Hume’s metaphysical claim that distinct existents are “entirely loose and separate”. But contemporary advocates of a Humean metaphysic accept a metaphysical claim stronger than Hume’s own. I argue that their view plausibly gives rise to a radical inductive skepticism–according to which we are downright irrational in believing as we do about the unobserved–that we (...) don’t otherwise have reason to accept. The Metaphysical Neo-Humean is in an epistemological quagmire all her own. (shrink)

ABSTRACT In Making Things Up, Bennett defends the intriguing idea that causation should be included among the building relations. I critique Bennett’s arguments for inclusion, and claim that inclusion distorts her own treatments of causation, relative fundamentality, and absolute fundamentality. Instead, I argue for treating causation and grounding as separate species of generative, explanatory difference-making.

Feminist metaphysics is guided by the insight that gender is socially constructed, yet the metaphysics behind social construction remains obscure. Barnes and Mikkola charge that current metaphysical frameworks—including my grounding framework—are hostile to feminist metaphysics. I argue that not only is a grounding framework hospitable to feminist metaphysics, but also that a grounding framework can help shed light on the metaphysics behind social construction. By treating social construction claims as grounding claims, the feminist metaphysician and the social ontologist both gain (...) a way to integrate social construction claims into a general metaphysics, while accounting for the inferential connections between social construction and attendant notions such as dependence and explanation. So I conclude that a grounding framework can be helpful for feminist metaphysics and social ontology. (shrink)

In the second half of this essay, I discuss the robust conception of rationality that lies at the heart of the Kantian version of Rationalist Constructivism – offering some reasons to prefer this conception to the more minimal accounts of rationality associated with Humean views. I then go on to discuss some of the potential metaethical advantages of the resulting form of constructivism.

What does it mean that some proposition follows from others? The standard way of spelling out the notion proceeds in modal terms: x follows from y iff necessarily, if y is true, so is x. But although this yields a useful and manageable account of consequence, it fails to capture certain aspects of our pre-theoretical understanding of consequence. In this paper, an alternative notion of logical consequence, based on the idea of grounding, is developed.

The notion of grounding has gained increasing acceptance among metaphysicians in recent years. In this paper, I argue that this notion can be used to formulate a very attractive version of (property) nominalism, a view that I call ‘grounding nominalism’. Simplifying somewhat, this is the view that all properties are grounded in things. I argue that this view is coherent and has a decisive advantage over competing versions of nominalism: it allows us to accept properties as real, while fully accommodating (...) nominalist intuitions. Finally, I defend grounding nominalism against several seemingly troublesome objections. (shrink)

Grounding is often glossed as metaphysical causation, yet no current theory of grounding looks remotely like a plausible treatment of causation. I propose to take the analogy between grounding and causation seriously, by providing an account of grounding in the image of causation, on the template of structural equation models for causation.

The paper deals with the notions of grounding and of existential dependence. It is shown that cases of existential dependence seem to be systematically correlated to cases of grounding and hence the question is raised what sort of tie might hold the two notions together so as to account for the observed correlation. The paper focusses on three possible ties between grounding and existential dependence: identity, definition, and grounding. A case for the definitional tie is made.

Recently, philosophers have tried to develop a version of truthmaker theory which ties the truthmaking relation closely to the notion of fundamentality. In fact, some of these truthmaker-fundamentalists, as I call them, assume that the notion of fundamentality is intelligible in part by citing, as central examples of fundamentals, truthmakers, which they understand necessarily as constituents of fundamental reality. The aim of this paper is first to bring some order and clarity to this discussion, sketching how far TF is compatible (...) with orthodox truthmaking, and then critically to evaluate the limits of TF. It will be argued that truthmaker theory cannot directly help with articulating the nature of fundamental reality and that T-REL does not necessarily relate truths with anything more fundamental, unless what is fundamental is what the truthbearers in question are about. I shall argue that TF faces a rather thorny dilemma and some general problems. I shall present two exhaustive types of fundamentalism on which a version of TF can be based: deflationary and inflationary. It will be argued that each version of TF runs into significant troubles accounting for all truth, specifically ordinary truths and metaphysical truths about the relations between ordinary facts and fundamental facts. I shall not attempt to solve these problems, but rather, at the end, diagnose the issues with TF as lying in the difficulties with reconciling the manifest image with the scientific and metaphysical images of reality. (shrink)

In spite of its significance for everyday and philosophical discourse, the explanatory connective has not received much treatment in the philosophy of logic. The present paper develops a logic for based on systematic connections between and the truth-functional connectives.

Philosophy and Phenomenological Research, Volume 99, Issue 3, Page 749-767, November 2019.

The paper focusses on two claims about metaphysical structure: Atomism and Fundamentalism. The first of these claims says that there are mereological atoms, i.e. minimal elements in the mereological structure of reality. The second says that there are fundamental truths, i.e. minimal elements in the grounding structure of reality. A philosopher who defended both of these claims was Bernard Bolzano; the present paper is an exploration of his views on the matter.

I give shape to a neglected debate in metaphysics, the debate over the ontological priority between individuality and collectivity. I distinguish the debate from more familiar ones in the recent literature and articulate what I call ontological collectivism, the view that collectivity is prior to individuality. I defend the in-principle intelligibility of the view from forceful general objections and argue that not only is it coherent but also of significant interest to the literature: it allows for overlooked alternatives on a (...) variety of central discussions. (shrink)

Some revisionary ontologies are highly parsimonious: they posit far fewer entities than what we quantify over in ordinary discourse. The most radical examples are minimal ontologies, on which physical simples are the only things that exist. Highly parsimonious ontologies, and especially minimal ones, face the challenge of either accounting for the truth of our ordinary quantificational discourse, or paraphrasing such discourse away. Common strategies for addressing this challenge include classical reduction, paraphrase nihilism, and a distinction between ontological and existence commitments. (...) I argue, however, that these strategies are either implausible or fail to provide truth conditions consistent with minimal or parsimonious ontologies. I then discuss, defend, and suggest ways to strengthen an alternative framework for reduction, on which the sentences of reducing theories ground those of reducible theories. Relative to the other options for defending minimal ontology, a strengthened grounding-reductive approach can provide more defensible truth conditions for minimal ontology, better preserve scientific realist intuitions, set a more attainable standard for reduction, and allow our existence commitments to be more responsive to empirical evidence and scientific expertise. As a result, I argue that minimal ontology becomes more defensible—though not certain—on a grounding-reductive framework. But even if minimal ontology were wrong, the grounding-reductive framework makes other parsimonious but non-minimal ontologies more plausible. (shrink)

As I will use the term, an object is a mereological sum of some things just in case those things compose it simply in virtue of existing. In the first half of this paper, I argue that there are no sums. The key premise for this conclusion relies on a constraint on what, in certain cases, it takes for something to ground, or metaphysically explain, something else. In the second half, I argue that in light of my argument against sums, (...) Universalism, which is perhaps the most widely accepted answer to the Special Composition Question, is false. (shrink)

In this paper, I both propose and discuss a novel account of truthmaking. I begin by showing what truthmaking is not: it is not grounding and it is not correspondence. I then show what truthmaking is by offering an account that appeals both to grounding and what I call ‘deep correspondence’. After I present the account and show that it is an account that unifies, I put it to work by showing how it can overcome an objection to truthmaking, how (...) we can get truthmaking from correspondence, what it says about truthmaker necessitation, and how it can explain a connection between truthmaker maximalism and pluralism about truth. (shrink)

The statue and the lump of clay that constitutes it fail to share all of their kind and modal properties. Therefore, by Leibniz’s Law, the statue is not the lump. Question: What grounds the kind and modal differences between the statue and the lump? In virtue of what is it that the lump of clay, but not the statue, can survive being smashed? This is the grounding problem. Now a number of solutions to the grounding problem require that we substantially (...) revise our view of reality. In this paper, I provide a solution to this problem that does not require such a revision. I then show how my solution to the grounding problem can solve a related problem and answer a related question. The upshot is that the solution I offer is not only non-revisionary, but also fruitful. (shrink)

Recent metaphysics has seen a surge of interest in grounding—a relation of non-causal determination underlying a distinctive kind of explanation common in philosophy. In this article, I investigate the connection between grounding and another phenomenon of great interest to metaphysics: ontological dependence. There are interesting parallels between the two phenomena: for example, both are commonly invoked through the use of “dependence” terminology, and there is a great deal of overlap in the motivations typically appealed to when introducing them. I approach (...) the question of the relationship between grounding and ontological dependence through an investigation of their modal connections. I argue, firstly, that on the common assumption that grounding is factive, it can be shown that no known variety of rigid ontological dependence is either necessary or sufficient for grounding. I also offer some suggestions in support of the claim that this generalizes to every possible form of rigid ontological dependence. I then broaden the discussion by considering a non-factive conception of grounding, as well as by looking at forms of generic ontological dependence. I argue that there is at least one form of rigid ontological dependence that is sufficient for non-factive grounding, and that a form of generic dependence may be necessary both for factive and non-factive grounding. However, justifying even these fairly weak modal connections between grounding and ontological dependence turns out to require some quite specific and substantive assumptions about the two phenomena that have only rarely been discussed. (shrink)

This article explores the concept of metaphysically opaque grounding, a largely neglected form of metaphysical grounding that challenges the commonly held assumptions that grounding is an especially intimate and powerful connection between facts and that it is necessarily connected with the essences of things. I provide a definition of opaque grounding, identify some interesting philosophical views that are committed to it, and explore some consequences for the general theory of grounding. Finally, I briefly address some natural initial doubts about opaque (...) grounding and find them unwarranted. The upshot is that the notion deserves more attention than it has previously received. (shrink)

I argue that libertarian paternalism is in fact paternalism, or hard paternalism, rather than a form of soft paternalism. I do so on the basis of an analysis of the paternalist act according to which the paternalist act needn’t violate the will of the agent who is the target of that act and the paternalist actor need only suspect that her action may improve the welfare of that target. The paper considers and rejects interpretations of libertarian paternalism as soft paternalism. (...) I then provide an outline as to how libertarian paternalism may be reformed in light of the finding that current libertarian paternalism is hard paternalism. The proposal is to require that the enactment of libertarian paternalist policies be conditional on opinion polling indicating support for those policies from the agents they target. (shrink)

Suppose that all non-qualitative facts are grounded in qualitative facts. I argue that this view naturally comes with a picture in which trans-world identity is indeterminate. But this in turn leads to either pervasive indeterminacy in the non-qualitative, or else contingency in what facts about modality and possible worlds are determinate.

David Lewis holds that a single possible world can provide more than one way things could be. But what are possible worlds good for if they come apart from ways things could be? We can make sense of this if we go in for a metaphysical understanding of what the world is. The world does not include everything that is the case—only the genuine facts. Understood this way, Lewis's “cheap haecceitism” amounts to a kind of metaphysical anti-haecceitism: it says there (...) aren't any genuine facts about individuals over and above their qualitative roles. (shrink)

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. (shrink)

ABSTRACTThe paper explores Stephen Yablo's suggestion that ‘If-Thenism’ in the philosophy of mathematics is best formulated as the thesis that the real content of a mathematical claim C is the result of subtracting the potentially problematic metaphysical commitments of mathematics from C [Yablo 2017]. Yablo's proposal assumes that some propositions make others true. The present discussion assumes that propositions are coarse-grained sets of possible worlds and asks what Yablo's proposal looks like on that assumption. The conclusion is that the adequacy (...) of the proposal turns on hard-to-settle questions about the truthmakers for propositions expressed by material conditionals. (shrink)

Schaffer offers us in the last section of “On What Grounds What” (2009) an applied illustration of his allegedly Aristotelian metaontological position. According to this illustration, Schaffer’s metaontological position, supplemented with a few Aristotelian theses about substance and grounding, would converge in a view remarkably similar to his priority monism (Philosophical Studies, 145, 131–148, 2009b; Philosophical Review, 119, 31–76, 2010a), the view that there is one single fundamental substance. In this paper, I will argue against Schaffer’s suggestion that priority monism (...) represents a viable development of Aristotelian metaphysics. In particular, I will hold that the most plausible version of Schaffer’s priority monism by Aristotelian standards fails to satisfy basic Aristotelian tenets about dependence, composition, change, and persistence, and suggest that this is evidence that Aristotelians are more at home with a pluralism rather than a monism about substance. (shrink)

According to an increasingly popular view among philosophers of science, both causal and non-causal explanations can be accounted for by a single theory: the counterfactual theory of explanation. A kind of non-causal explanation that has gained much attention recently but that this theory seems unable to account for are grounding explanations. Reutlinger :239-256, 2017) has argued that, despite these appearances to the contrary, such explanations are covered by his version of the counterfactual theory. His idea is supported by recent work (...) on grounding by Schaffer and Wilson who claim there to be a tight connection between grounding and counterfactual dependence. The present paper evaluates the prospects of the idea. We show that there is only a weak sense in which grounding explanations convey information about counterfactual dependencies, and that this fact cannot plausibly be taken to reveal a distinctive feature that grounding explanations share with other kinds of explanations. (shrink)

Abstract This paper illustrates how Aristotle's topological theses about change in Physics 5-6 can help address metaphysical issues. Two distinctions from Physics 5. 1 are discussed: changing per se versus changing per aliud ; motion versus change. Change from white to black is motion and alteration, whereas change from white to not white is neither. But is not every change from white to black identical with a change from white to not white? Theses from Physics 6 refute the identity. Is (...) change from white to black at least accompanied by change from white to not white? Perhaps, but given further theses from Physics 6, this supposition yields unwelcome consequences. Most likely, when something changes from white to black it changes merely per aliud , not per se , from white to not white. Genuine change between white and not white is found elsewhere; its admission has bearing on Aristotle's theory of perception. (shrink)

ABSTRACT Bennett argues that the various building relations are all directed, necessitating and generative. This note provides interpretations of these conditions different from Bennett’s. According to Bennett, the full builders for an entity must necessitate its existence alone or in conjunction with other items that are not builders. I suggest that the full builders must necessitate the built item outright. According to Bennett, building is generative only in the sense that when the xx build y we are thereby “licensed” to (...) say that y exists/obtains because the xx exist/obtain. I suggest that the building relations are unified by the fact that when the xx build y, the xx together metaphysically ground y. This entails, contra Bennett, that causation is not a building relation. (shrink)

It is sometimes mentioned that Bernard Bolzano’s work on grounding anticipates many insights of the current debate on metaphysical grounding. The present paper discusses a certain part of Bolzano’s theory of grounding that has thus far not been discussed in the literature. This part does not so much anticipate what are nowadays common assumptions about grounding, but rather goes beyond them. Central to the discussion will be a thesis of Bolzano’s by which he tries to establish a connection between grounding (...) and unification. The paper spells out this thesis in detail and discusses the assumptions on which it rests. Next to this mainly historical aim, the paper also presents reasons why philosophers who are not interested in the historical Bolzano should find the thesis interesting by relating it to a certain view on unification and explanation that has been put forward by Kim. A final part of the paper provides a critical evaluation of the thesis against the background of current accounts of grounding. (shrink)

Some metaphysicians believe that metaphysical modality is explainable by the essences of objects. In §II, I spell out the definitional view of essence, and in §III, a working notion of metaphysical explanation. Then, in §IV, I consider and reject five natural ways to explain necessity by essence: in terms of the principle that essential properties can't change, in terms of the supposed obviousness of the necessity of essential truth, in terms of the logical necessity of definitions, in terms of Fine's (...) logic of essence, and in terms of the theory of real definitions. I will conclude that the present evidence favours rejecting the hypothesis that modality is explainable by essence. (shrink)

A generic grounding claim is a grounding claim that isn’t about any particular entity or fact. For example, consider the claim: an act is right in virtue of maximizing happiness. One natural idea is that generic grounding claims state mere regularities of ground. So if an act is right in virtue of maximizing happiness, then every possible right act is right in virtue of maximizing happiness. The generic claim generalizes over particular grounding relations. In this essay, I argue that this (...) simple story is wrong. Generic grounding claims are not merely quantificational; rather, they express real definitions, where real definitions are (in part) claims about essence. My view has two major upshots: ('i') it makes better sense of debates where generic grounding claims are at issue (like debates about moral laws); ('ii') it clarifies the distinction between reductive and non-reductive metaphysical theories. (shrink)

It is common to think that grounding is necessary in the sense that: if P grounds Q, then necessarily: if P, then Q. Though most accept this principle, some give counterexamples to it. Instead of straightforwardly arguing for, or against, necessity, I explain the sense in which grounding is necessary and contingent. I argue that there are two kinds of grounding: what-grounding and why-grounding, where the former kind is necessary while the latter is contingent.

Grounding pluralism is the view that there are multiple kinds of grounding. In this essay, I motivate and defend an explanation-theoretic view of grounding pluralism. Specifically, I argue that there are two kinds of grounding: why-grounding—which tells us why things are the case—and how-grounding—which tells us how things are the case.

In the recent philosophy of explanation, a growing attention to and discussion of non-causal explanations has emerged, as there seem to be compelling examples of non-causal explanations in the sciences, in pure mathematics, and in metaphysics. I defend the claim that the counterfactual theory of explanation (CTE) captures the explanatory character of both non-causal scientific and metaphysical explanations. According to the CTE, scientific and metaphysical explanations are explanatory by virtue of revealing counterfactual dependencies between the explanandum and the explanans. I (...) support this claim by illustrating that CTE is applicable to Euler’s explanation (an example of a non-causal scientific explanation) and Loewer’s explanation (an example of a non-causal metaphysical explanation). (shrink)

In the recent philosophy of explanation, a growing attention to and discussion of non-causal explanations has emerged, as there seem to be compelling examples of non-causal explanations in the sciences, in pure mathematics, and in metaphysics. I defend the claim that the counterfactual theory of explanation captures the explanatory character of both non-causal scientific and metaphysical explanations. According to the CTE, scientific and metaphysical explanations are explanatory by virtue of revealing counterfactual dependencies between the explanandum and the explanans. I support (...) this claim by illustrating that CTE is applicable to Euler’s explanation and Loewer’s explanation. (shrink)

In this paper, I offer a new theory of grounding. The theory has it that grounding is a job description that is realized by different properties in different contexts. Those properties play the grounding role contingently, and grounding is the property that plays the grounding role essentially. On this theory, grounding is monistic, but ‘grounding’ refers to different relations in different contexts. First, I argue against Kit Fine’s monist univocalism. Next, I argue against Jessica Wilson’s pluralist multivocalism. Finally, I introduce (...) monist multivocalism, explicate three versions of it (of which the above is one), and show its advantages. (shrink)

In the middle of the 20th century, it was a common Wittgenstein-inspired idea in philosophy that for a linguistic expression to have a meaning is for it to be governed by a rule of use. In other words, it was widely believed that meanings are to be identified with use-conditions. However, as things stand, this idea is widely taken to be vague and mysterious, inconsistent with “truth-conditional semantics”, and subject to the Frege-Geach problem. In this paper I reinvigorate the ideas (...) that meaningfulness is a matter of being governed by rules of use and that meanings are best thought of in terms of use-conditions. I will do this by sketching the Rule-Governance view of the nature of linguistic meaningfulness, showing that the view isn’t by itself subject to the two problems, and explain why the idea has had a lasting appeal to philosophers from Strawson to Kaplan and why we should find it continually attractive. (shrink)

This is a survey of the concept of continuity. Efforts to explicate continuity have produced a plurality of philosophical conceptions of continuity that have provably distinct expressions within contemporary mathematics. I claim that there is a divide between the conceptions that treat the whole continuum as prior to its parts, and those conceptions that treat the parts of the continuum as prior to the whole. Along this divide, a tension emerges between those conceptions that favor philosophical idealizations of continuity and (...) those that are more readily available for mathematico-scientific use. (shrink)

There has been much recent interest in a distinctively metaphysical kind of determinative explanation: ground. This paper concerns various skeptical challenges to ground’s relevance to metaphysics, such as that it is an empty posit, that the work it is supposed to do is appropriated by other notions, and that it is inapt for specific issues it should serve. I argue against these challenges. My strategy is both critical and constructive. Critical because I argue that versions of these challenges raised by (...) Elizabeth Barnes, Kathrin Koslicki, Mari Mikkola, and Jessica Wilson are not persuasive. Constructive because we may nevertheless learn from them new work for ground. (shrink)

I defend (metaphysical) ground against recent, unanswered objections aiming to dismiss it from serious philosophical inquiry. Interest in ground stems from its role in the venerable metaphysical project of identifying which facts hold in virtue of others. Recent work on ground focuses on regimenting it. But many reject ground itself, seeing regimentation as yet another misguided attempt to regiment a bad idea (like phlogiston or astrology). I defend ground directly against objections that it is confused, incoherent, or fruitless. This vindicates (...) the very attempt to regiment ground. It also refocuses our attention on the genuine open questions about ground and away from the distracting, unpersuasive reasons for dismissing them. (shrink)

A commonly held view is that a central aim of metaphysics is to give a fundamental account of reality which refers only to the fundamental entities. But a puzzle arises. It is at least a working hypothesis for those pursuing the aim that, first, there must be fundamental entities. But, second, it also seems possible that the world has no foundation, with each entity depending on others. These two claims are inconsistent with the widely held third claim that the fundamental (...) just is the foundational. It is tempting to resolve the puzzle by rejecting the first or second claim, perhaps because it is obscure how the third claim might plausibly be challenged. But I develop a new analysis of fundamentality which challenges the third claim by allowing for an entity to be fundamental without being foundational. The analysis, roughly, is that an entity is fundamental just in case not all facts about it are grounded in facts about other entities. The possibility of fundamentality without foundations not only provides for a novel resolution to the puzzle, but has applications to some live debates: for example, it undermines Jonathan Schaffer's modal argument for priority monism. (shrink)

This essay focuses on a recently prominent notion of ground which is distinctive for how it links metaphysics to explanation. Ground is supposed to serve both as the common factor in diverse in virtue of questions as well as the structuring relation in the project of explaining how some phenomena are “built” from more fundamental phenomena. My aim is to provide an opinionated synopsis of this notion of ground without engaging with others. Ground, so understood, generally resists illumination by appeal (...) to more familiar models of explanation. Nevertheless, its distinctive explanatory and metaphysical aspects guide us on characterizing its explanatory logic and its metaphysical features. Some issues concerning the meta-question of what grounds ground are explored, as well as some recent skeptical challenges to ground. (shrink)