Jonathan Schaffer

Quantum mechanics seems to portray nature as nonseparable, in the sense that it allows spatiotemporally separated entities to have states that cannot be fully specified without reference to each other. This is often said to implicate some form of “holism.” We aim to clarify what this means, and why this seems plausible. Our core idea is that the best explanation for nonseparability is a “common ground” explanation, which casts nonseparable entities in a holistic light, as scattered reflections of a more unified underlying reality.

Knowledge ascriptions seem context sensitive. Yet it is widely thought that epistemic contextualism does not have a plausible semantic implementation. We aim to overcome this concern by articulating and defending an explicit contextualist semantics for ‘know,’ which integrates a fairly orthodox contextualist conception of knowledge as the elimination of the relevant alternatives, with a fairly orthodox “Amherst” semantics for A-quantification over a contextually variable domain of situations. Whatever problems epistemic contextualism might face, lack of an orthodox semantic implementation is not among them.

In _A Companion to David Lewis_, Barry Loewer and Jonathan Schaffer bring together top philosophers to explain, discuss, and critically extend Lewis's seminal work in original ways. Students and scholars will discover the underlying themes and complex interconnections woven through the diverse range of his work in metaphysics, philosophy of language, logic, epistemology, philosophy of science, philosophy of mind, ethics, and aesthetics. The first and only comprehensive study of the work of David Lewis, one of the most systematic and influential philosophers of the latter half of the 20th century Contributions shed light on the underlying themes and complex interconnections woven through Lewis's work across his enormous range of influence, including metaphysics, language, logic, epistemology, science, mind, ethics, and aesthetics Outstanding Lewis scholars and leading philosophers working in the fields Lewis influenced explain, discuss, and critically extend Lewis's work in original ways An essential resource for students and researchers across analytic philosophy that covers the major themes of Lewis's work

According to a line of thought tracing from Descartes, Leibniz, and Locke through to Kripke, Levine, and Chalmers, there is a special explanatory gap arising between the physical and the phenomenal. I argue that the physical-phenomenal gap is not special but rather that such gaps are pervasive, lurking in the transition from the physical to the chemical and in every concrete transition from more to less fundamental. Correlatively, I argue that such gaps are unproblematic, so long as they are bridged by substantive principles of metaphysical grounding. So I articulate a form of physicalism — “ground physicalism” — on which the physical grounds the chemical, the biological, and the psychological, and explain how ground physicalism resolves explanatory gap worries.

You drop the glass. It shatters. Here there are two distinct events, related by causation. What is this relation? ;I argue that the causal relation is best understood as the relation of being a probability-raiser of a process. I take the causal relata to be property instances at spatiotemporal regions, analyze the notion of a process in terms of sequences of events related by nomic subsumption , and understand probability-raising as counterfactual chance dependence in the style of David Lewis. Thus causes are understood as property instances on which the sequence of property instances constituting the lawful production of the effect depends. ;The understanding of causation offered here synthesizes the leading extant analyses of causation, which divide into probability-raising and process-linkage . I argue that the synthesis offered improves on its predecessors by developing a series of four problem cases: preemption, which shows causation without probability-raising, overlapping, which shows probability-raising without causation, double prevention, which shows causation without process-linkage, and mere traces, which shows process-linkage without causation. These objections interlock: the preempting cause and trace noncause are both process-linked to, but not probability-raising of, their alleged effects, while the double preventing cause and overlapping noncause are both probability-raising of, but not process-linked to, their alleged effects. Understanding causes as probability-raisers of processes resolves this problematic. A continuity requirement is then added which preserves these solutions, renders the relation continuous and transitive, and resolves a further problem case combining preemption and double-prevention involving causation without probability-raising or process-linkage

Are the sparse properties drawn from all the levels of nature, or only the fundamental level? I discuss the notion of sparse property found in Armstrong and Lewis, show that there are tensions in the roles they have assigned the sparse properties, and argue that the sparse properties should be drawn from all the levels of nature. The issue has direct bearing on reductionism. If the sparse properties are drawn from all the levels of nature, then macro‐scientific properties are just as primary as micro‐scientific properties, and do not need to be reduced to them.

What conception of causation is at work in the law? I argue that the law implicitly relies on a contrastive conception. In a liability case where the defendant's breach of duty must be shown to have caused the plaintiff's damages, it is not enough to consider what would have happened if the cause had not occurredthe law requires us to look to a specific replacement for the effect, which in this case is the hypothetical outcome in which the plaintiff came off better. In place of I suggest the more explicit An explicitly contrastive approach can thus potentially help the lawyer phrase her causal question in a more explicit way, while shedding light on our conception of causation

Metaphysical semantics is supposed to connect the nonfundamental to the fundamental in a distinctively “linguistic” way, explaining how nonfundamental truths can be grounded in fundamental facts , and so inducing a radically eliminative vision of the nonfundamental as mere talk. I wonder how the story goes when a single nonfundamental truth can be grounded in many different fundamental facts. For instance, the truth that Moore has hands can presumably be grounded in many different distributions of fields, arrangements of particles, vibrations of strings, or whatnot. I am asking how metaphysical semantics can accommodate this sort of multiple realizability

What knowledge is imperilled by sceptical doubt? That is, what range of beliefs may be called into doubt by sceptical nightmares like the Cartesian demon hypothesis? It is generally thought that demons have limited powers, perhaps only threatening a posteriori knowledge of the external world, but at any rate not threatening principles like the cogito. I will argue that there is a demon – the debasing demon – with unlimited powers, which threatens universal doubt. Rather than deceiving us with falsities, the debasing demon would allow us true beliefs, but only as guesses.

The physical and/or intrinsic connection approach to causation has become prominent in the recent literature, with Salmon, Dowe, Menzies, and Armstrong among its leading proponents. I show that there is a type of causation, causation by disconnection, with no physical or intrinsic connection between cause and effect. Only Hume-style conditions approaches and hybrid conditions-connections approaches appear to be able to handle causation by disconnection. Some Hume-style, extrinsic, absence-relating, necessary and/or sufficient condition component of the causal relation proves to be needed.

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.