Louis deRosset

There is a curious bifurcation in the literature on ground and its logic. On the one hand, there has been a great deal of work that presumes that logical complexity invariably yields grounding. So, for instance, it is widely presumed that any fact stated by a true conjunction is grounded in those stated by its conjuncts, that any fact stated by a true disjunction is grounded in that stated by any of its true disjuncts, and that any fact stated by a true double negation is grounded in that stated by the doubly-negated formula. This commitment is encapsulated in the system GG axiomatized and semantically characterized by [deRosset and Fine, 2023] (following [Fine, 2012]). On the other hand, there has been a great deal of important formal work on “flatter” theories of ground, yielding logics very different from GG [Correia, 2010] [Fine, 2016, 2017b]. For instance, these theories identify the fact stated by a self-conjunction $$(\phi \wedge \phi )$$ with that stated by its conjunct $$\phi $$. Since, in these systems, no fact grounds itself, the “flatter” theories are inconsistent with the principles of GG. This bifurcation raises the question of whether there is a single notion of ground suited to fulfill the philosophical ambitions of grounding enthusiasts. There is, at present, no unified semantic framework employing a single conception of ground for simultaneously characterizing both GG and the “flatter” approaches. This paper fills this gap by specifying such a framework and demonstrating its adequacy.

The scientific successes of the last 400 years strongly suggest a view on which things are organized into layers, with phenomena in higher layers dependent on and determined by what goes on below. Philosophers have recently explored the idea that we can make sense of this idea by appeal to a relation called grounding. This book develops the rudiments of a theory of grounding, and applies that theory to questions of independent interest. The theorizing consists in saying in more detail what grounding is and how it relates to explanations of the relevant sort, discussing objections to the deployment of a notion of grounding, and drawing points of contrast between a grounding-centered approach to relative fundamentality and other approaches in the literature. The book then turns to a demonstration of how this theorizing bears fruit in the investigation of other interesting questions. The applications are to central questions concerning (i) how to distinguish between truths that say how objective reality is in itself, quite independently of us, and truths that do not; (ii) the nature of truth; and (iii) the relation between fundamental physical facts and the rich panoply of other facts that depend on and are determined by them, including facts concerning our own doings. The aim is to advance our understanding of one of the deepest and thorniest questions which the stunning scientific achievements of the last 400 years pose: how higher-level phenomena, including ourselves, fit into an ultimately physical world.

The idea that some objects are metaphysically “cheap” has wide appeal. An influential version of the idea builds on abstractionist views in the philosophy of mathematics, on which numbers and other mathematical objects are abstracted from other phenomena. For example, Hume’s Principle states that two collections have the same number just in case they are equinumerous, in the sense that they can be correlated one-to-one: (HP) #xx=#yy iff xx≈yy. The principal aim of this article is to use the notion of grounding to develop this sort of abstractionism. The appeal to grounding enables a unified response to the two main challenges that confront abstractionism. First, we must explicate the metaphor of meta- physical “cheapness.” Second, we must rebut the “bad company” objection, which rejects abstraction principles like (HP) as tarnished by their similarity to inconsistent principles like Frege’s Basic Law V. By enforcing a simple requirement that all abstraction be properly grounded, we propose a unified solution to these two hard, and prima facie unrelated, problems. On our view, grounded abstraction simultaneously ensures “cheap” abstracta and permissible abstraction.

This paper establishes a sound and complete semantics for the impure logic of ground. Fine (Review of Symbolic Logic, 5(1), 1–25, 2012a) sets out a system for the pure logic of ground, one in which the formulas between which ground-theoretic claims hold have no internal logical complexity; and it provides a sound and complete semantics for the system. Fine (2012b) [§§6-8] sets out a system for an impure logic of ground, one that extends the rules of the original pure system with rules for the truth-functional connectives, the first-order quantifiers, and λ-abstraction. However, no semantics has yet been provided for this system. The present paper partly fills this lacuna by providing a sound and complete semantics for a system GG containing the truth-functional operators that is closely related to the truth-functional part of the system of Fine (2012b).

A raft of new philosophical problems concerning truth have recently been discovered by several theorists. These problems concern the question of how ascriptions of truth are to be grounded. Most previous commentators have taken the problems to shed light on the theory of ground. In this paper, I argue that they also shed light on the theory of truth. In particular, I argue that the notion of ground can be deployed to clearly articulate one strand of deflationary thinking about truth, according to which truth is “metaphysically lightweight.” I offer a ground-theoretic explication of the lightness of truth and show how it yields a novel solution to the problems concerning how truth is grounded. So, the theory of truth and the theory of ground interact fruitfully: we can apply the notion of ground to offer a clear explication of the deflationist claim that truth is “metaphysically lightweight” that both captures the motivations for that claim and solves the problems.

In Objects: Nothing Out of the Ordinary, Daniel Z. Korman defends a view he calls conservatism. Conservatives hold that there are ordinary objects, but no extraordinary objects. But Korman never explicitly characterizes what would qualify an object as ordinary in the relevant sense. We have some paradigm cases of ordinary objects, including tables, dogs, and trees; and we have some paradigm cases of extraordinary objects of sorts familiar from the philosophical literature. Here I attempt to fill this gap, surveying a number of attempts to characterize the commitments of conservatism. All fail. In particular, no specification of what it takes for an object to be ordinary is both plausible and consistent with the conservative verdicts on the paradigms. I argue that this is no coincidence, since it turns out to be implausible in light of the results of settled science to deny the existence of one of Korman's paradigms of an extraordinary object. The upshot is that plausibility requires being a little more liberal than conservatism seems to allow.

In (deRosset, 2015), I argued that there are counterexamples to the claim that the sentences analytically entailed by a claim φ require nothing more of the world for their truth than does φ. The counterexamples involve sentences which, I argued, are analytically entailed by certain truths, but which nevertheless require more of the world for their truth. John Horden has offered two interesting criticisms of this argument. First, he contends that its conclusion is inconsistent. Second, he contends that the argument faces a dilemma, depending on which of two hypotheses about the meanings of the sentences involved in the counterexamples turns out to be true. Here I reply to Horden’s criticisms and briefly indicate what I take their lesson to be.

In Objects: Nothing Out of the Ordinary, Daniel Z. Korman defends a view he calls conservatism. Conservatives hold that there are ordinary objects, but no extraordinary objects. But Korman never explicitly characterizes what would qualify an object as ordinary in the relevant sense. We have some paradigm cases of ordinary objects, including tables, dogs, and trees; and we have some paradigm cases of extraordinary objects of sorts familiar from the philosophical literature. Here I attempt to fill this gap, surveying a number of attempts to characterize the commitments of conservatism. All fail. In particular, no specification of what it takes for an object to be ordinary is both plausible and consistent with the conservative verdicts on the paradigms. I argue that this is no coincidence, since it turns out to be implausible in light of the results of settled science to deny the existence of one of Korman's paradigms of an extraordinary object. The upshot is that plausibility requires being a little more liberal than conservatism seems to allow.

In "Analyticity and Ontology," I argued that there are counterexamples to the claim that the sentences analytically entailed by a claim $\phi$ require nothing more of the world for their truth than does $\phi$. The counterexamples involve sentences which, I argued, are analytically entailed by certain truths, but which nevertheless require more of the world for their truth. John Horden has offered two interesting criticisms of this argument. First, he contends that its conclusion is inconsistent. Second, he contends that the argument faces a dilemma, depending on which of two hypotheses about the meanings of the sentences involved in the counterexamples turns out to be true. Here I reply to Horden's criticisms and briefly indicate what I take their lesson to be.

Saul Kripke has claimed that there are necessary connections between material things and their material origins. The usual defences of such necessity of origin theses appeal to either a sufficiency of origin principle or a branching-times model of necessity. In this paper we offer a different defence. Our argument proceeds from more modest ‘independence principles’, which govern the processes by which material objects are produced. Independence principles are motivated, in turn, by appeal to a plausible metaphysical principle governing such processes, their invulnerability to non-local prevention. We outline the new argument, and distinguish it from both of the usual defences.

A New Route to the Necessity of Origin’ (2004, henceforth ‘NR’), we offered an argument for the thesis that there are necessary connections between material things and their material origins. Much of the philosophical interest lay in our claim that the argument did not depend on so-called sufficiency principles for crossworld identity. It has been the verdict of much recent work on the necessity of origin that valid arguments for the thesis require some such sufficiency principle as a premise but that such principles are deeply problematic.1 Finding an argument free of such principles would advance both our understanding and the plausibility of that thesis. These claims are now the subject of a pair of insightful critiques by Teresa Robertson and Graeme Forbes (2006, henceforth ‘RF’) and by Ross Cameron and Sonia Roca (2006, henceforth ‘CR’), and we welcome the opportunity to clarify and improve our account of the matter.

A major source of latter-day skepticism about necessity is the work of David Hume. Hume is widely taken to have endorsed the Humean claim: there are no necessary connections between distinct existences. The Humean claim is defended on the grounds that necessary connections between wholly distinct things would be mysterious and inexplicable. Philosophers deploy this claim in the service of a wide variety of philosophical projects. But Saul Kripke has argued that it is false. According to Kripke, there are necessary connections between distinct existences; in particular, there are necessary connections between material objects and their material origins. In this paper I argue that the primary motivation for the Humean claim, Hume's datum, also motivates the key premise in an argument for the necessity of origins. The very considerations that the Humean takes to show that necessary connections between wholly distinct things would be mysterious and inexplicable indicate that there must be some such necessary connections. Thus, in the absence of alternative support, there is no reason to believe the Humean claim.

Among the most remarkable developments in metaphysics since the 1950’s is the explosion of philosophical interest in possible worlds. This paper proposes an explanation of what possible worlds are, and argues that this proposal, the interpreted models conception, should be attractive to anyone who thinks that modal facts are primitive, and so not to be explained in terms of some non-modal notion of “possible world.” I articulate three constraints on any acceptable primitivist explanation of the nature of possible worlds, and show that the interpreted models conception meets the three constraints.

A standard view of reference holds that a speaker's use of a name refers to a certain thing in virtue of the speaker's associating a condition with that use that singles the referent out. This view has been criticized by Saul Kripke as empirically inadequate. Recently, however, it has been argued that a version of the standard view, a /response-based theory of reference/, survives the charge of empirical inadequacy by allowing that associated conditions may be largely or even entirely implicit. This paper argues that response-based theories of reference are prey to a variant of the empirical inadequacy objection, because they are ill-suited to accommodate the successful use of proper names by pre-school children. Further, I argue that there is reason to believe that normal adults are, by and large, no different from children with respect to how the referents of their names are determined. I conclude that speakers typically refer /positionally/: the referent of a use of a proper name is typically determined by aspects of the speaker's position, rather than by associated conditions present, however implicitly, in her psychology.

A compelling idea holds that reality has a layered structure. We often disagree about what inhabits the bottom layer, but we agree that higher up we find chemical, biological, geological, psychological, sociological, economic, /etc./, entities: molecules, human beings, diamonds, mental states, cities, interest rates, and so on. How is this intuitive talk of a layered structure of entities to be understood? Traditionally, philosophers have proposed to understand layered structure in terms of either reduction or supervenience. But these traditional views face well-known problems. A plausible alternative is that layered structure is to be explicated by appeal to explanations of a certain sort, termed / grounding explanations/. Grounding explanations tell us what obtains in virtue of what. Unfortunately, the use of grounding explanations to articulate the layered conception faces a problem, which I call /the collapse/. The collapse turns on the question of how to ground the facts stated by the explanations themselves. In this paper I make a suggestion about how to ground explanations that avoids the collapse. Briefly, the suggestion is that the fact stated by a grounding explanation is grounded in its /explanans/

Though the study of grounding is still in the early stages, Kit Fine, in ”The Pure Logic of Ground”, has made a seminal attempt at formalization. Formalization of this sort is supposed to bring clarity and precision to our theorizing, as it has to the study of other metaphysically important phenomena, like modality and vagueness. Unfortunately, as I will argue, Fine ties the formal treatment of grounding to the obscure notion of a weak ground. The obscurity of weak ground, together with its centrality in Fine’s system, threatens to undermine the extent to which this formalization offers clarity and precision. In this paper, I show how to overcome this problem. I describe a system, the logic of strict ground (LSG) and demonstrate its adequacy; I specify a translation scheme for interpreting Fine’s weak grounding claims; I show that the interpretation verifies all of the principles of Fine’s system; and I show that derivability in Fine’s system can be exactly characterized in terms of derivability in LSG. I conclude that Fine’s system is reducible to LSG.

The scientific successes of the last 400 years strongly suggest a picture on which our scientific theories exhibit a layered structure of dependence and determination. Economics is dependent on and determined by psychology; psychology in its turn is, plausibly, dependent on and determined by biology; and so it goes. It is tempting to explain this layered structure of dependence and determination among our theories by appeal to a corresponding layered structure of dependence and determination among the entities putatively treated by those theories. In this paper, I argue that we can resist this temptation: we can explain the sense in which, e.g., the biological truths are dependent on and determined by chemical truths without appealing to properly biological or chemical entities. This opens the door to a view on which, though there are more truths than just the purely physical truths, there are no entities, states, or properties other than the purely physical entities, states, and properties. I argue that some familiar strategies to explicate the idea of a layered structure of theories by appeal to reduction, ground, and truthmaking encounter difficulties. I then show how these difficulties point the way to a more satisfactory treatment which appeals to something very close to the notion of ground. Finally, I show how this treatment provides a theoretical setting in which we might fruitfully frame debates about which entities there really are.

A philosophical standard in the debates concerning material constitution is the case of a statue and a lump of clay, Goliath and Lumpl, respectively. According to the story, Lumpl and Goliath are coincident throughout their respective careers. Monists hold that they are identical; pluralists that they are distinct. This paper is concerned with a particular objection to pluralism, the Grounding Problem. The objection is roughly that the pluralist faces a legitimate explanatory demand to explain various differences she alleges between Lumpl and Goliath, but that the pluralist’s theory lacks the resources to give any such explanation. In this paper, I explore the question of whether there really is any problem of this sort. I argue (i) that explanatory demands that are clearly legitimate are easy for the pluralist to meet; (ii) that even in cases of explanatory demands whose legitimacy is questionable the pluralist has some overlooked resources; and (iii) there is some reason for optimism about the pluralist’s prospects for meeting every legitimate explanatory demand. In short, no clearly adequate statement of a Grounding Problem is extant, and there is some reason to believe that the pluralist can overcome any Grounding Problem that we haven’t thought of yet.

Consider the kinds of macroscopic concrete objects that common sense and the sciences allege to exist: tables, raindrops, tectonic plates, galaxies, and the rest. Are there any such things? Opinions differ. Ontological liberals say they do; ontological radicals say they don't. Liberalism seems favored by its plausible acquiescence to the dictates of common sense abetted by science; radicalism by its ontological parsimony. Priority theorists claim we can have the virtues of both views. They hold that tables, raindrops, etc., exist, but they aren't fundamental. The ontological liberal's ontology provides the correct inventory of existent individuals. The ontological radical's more restricted ontology provides the correct inventory of fundamental individuals. The priority theorist claims that the derivative individuals are "no addition in being" to the fundamental ones, so we can have our cake and eat it too. It would be nice if priority theorists were right. In this paper I argue, with regret, that they are not. One upshot is that the sort of explanations which underwrite the priority theorist's distinction between fundamental and derivative individuals do not mitigate our ontological commitments. Another is that we still have to choose between the charms of liberalism and radicalism

It is difficult to wander far in contemporary metaphysics without bumping into talk of possible worlds. And, reference to possible worlds is not confined to metaphysics. It can be found in contemporary epistemology and ethics, and has even made its way into linguistics and decision theory. What are those possible worlds, the entities to which theorists in these disciplines all appeal? Some have hoped that a theory of possible worlds can be used to reduce modality to non-modal terms. This paper sets reductive theories aside, and articulates and applies a framework for evaluating non-reductive theories of possible worlds. I argue that, if we abjure reduction, we should aim for a theory of possible worlds that is user-friendly. I then outline four leading contemporary theories and consider objections to each. My conclusions are negative: every theory we discuss fails to be user-friendly in some significant respect.

Philosophers have spilled a lot of ink over the past few years exploring the nature and significance of grounding. Kit Fine has made several seminal contributions to this discussion, including an exact treatment of the formal features of grounding [Fine, 2012a]. He has specified a language in which grounding claims may be expressed, proposed a system of axioms which capture the relevant formal features, and offered a semantics which interprets the language. Unfortunately, the semantics Fine offers faces a number of problems. In this paper, I review the problems and offer an alternative that avoids them. I offer a semantics for the pure logic of ground that is motivated by ideas already present in the grounding literature, and for which a natural axiomatization capturing central formal features of grounding is sound and complete. I also show how the semantics I offer avoids the problems faced by Fine’s semantics.

Kit Fine, in "The Pure Logic of Ground", has made a seminal attempt at formalizing the notion of ground. Fine ties the formal treatment of grounding to the notion of a weak ground. Formalization of this sort is supposed to bring clarity and precision to our theorizing. Unfortunately, as I will argue, it's not clear what weak ground is. I review five alternative explanations of the idea, and argue that none of them are ultimately satisfactory. I close by outlining a more complicated explanation of the notion that turns out to be more satisfactory.

Necessitists hold that, necessarily, everything is such that, necessarily, something is identical to it. Timothy Williamson has posed a number of challenges to contingentism, the negation of necessitism. One such challenge is an argument that necessitists can more wholeheartedly embrace possible worlds semantics than can contingentists. If this charge is correct, then necessitists, but not contingentists, can unproblematically exploit the technical successes of possible worlds semantics. I will argue, however, that the charge is incorrect: contingentists can embrace possible worlds semantics as wholeheartedly as necessitists. Williamson offers a criterion for a class of models of quantified modal logic to be intended, and argues on its basis that contingentists must deny that there is an intended class of models. I argue that Williamson’s criterion is objectionable, supply an alternative that does not support Williamson’s argument, and adapt Williamson’s construction of an intended model structure to the needs of contingentist metaphysics.

/Analyticity theorists/, as I will call them, endorse the /doctrine of analyticity in ontology/: if some truth P analytically entails the existence of certain things, then a theory that contains P but does not claim that those things exist is no more ontologically parsimonious than a theory that also claims that they exist. Suppose, for instance, that the existence of a table in a certain location is analytically entailed by the existence and features of certain particles in that location. The doctrine implies that the table's existence requires nothing more of the world than that those particles exist and bear the features in question. Analyticity theorists have alleged that this idea may be used to defend controversial existence claims against a battery of objections. I argue that this style of defense fails, because the doctrine faces counter-examples. An existence claim may be analytically entailed by some truth and still report a substantial further fact.

It is difficult to wander far in contemporary metaphysics without bumping into talk of possible worlds. And reference to possible worlds is not confined to metaphysics. It can be found in contemporary epistemology and ethics, and has even made its way into linguistics and decision theory. What are those possible worlds, the entities to which theorists in these disciplines all appeal? This paper sets out and evaluates a leading contemporary theory of possible worlds, David Lewis's Modal Realism. I note two competing ambitions for a theory of possible worlds: that it be reductive and user-friendly. I then outline Modal Realism and consider objections to the effect that it cannot satisfy these ambitions. I conclude that there is some reason to believe that Modal Realism is not reductive and overwhelming reason to believe that it is not user-friendly.