In this paper, we argue that what is often discussed under the umbrella of `spacetime emergence' in the philosophy of quantum gravity in fact consists of a plethora of distinct and even highly different problems. We therefore advocate to cast such debates more specifically in terms of the emergent spatiotemporal aspects, as is already done in the physics literature. We first show how ambiguous the notion of spacetime is already in general relativity. We then argue against three ways to reject (...) our call for specificity: the many distinct philosophical problems relating to the emergence of the various spatiotemporal aspects do not suggest any singular, overarching, or exceptional problem of spacetime emergence. We also discuss how the objections are reflected by five conceptions of spacetime. Next, we observe that different spatiotemporal aspects are emergent in the different quantum gravity approaches, whereby investigating emergence in quantum gravity collectively is problematic. Finally, we illustrate how philosophical inquiries that employ notions of spacetime emergence are aided by conducting the investigation at the level of specific spatiotemporal aspects. (shrink)

The existence and fundamentality of spacetime has been questioned in quantum gravity where spacetime is frequently described as emerging from a more fundamental non-spatiotemporal ontology. This is supposed to lead to various philosophical issues such as the problem of empirical coherence. Yet those issues assume beforehand that we actually understand and agree on the nature of spacetime. Reviewing popular conceptions of spacetime, we find that there is substantial disagreement on this matter, and little hope of resolving it. However, we argue (...) that this should not trouble us as these issues, which seem to suggest the need for an account of spacetime in quantum gravity, can be addressed without one. (shrink)

This book defends a relational theory of the passage of time. The realist view of passage developed in this book differs from the robust, substantivalist position. According to relationism, passage is nothing over and above the succession of events, one thing coming after another. Causally related events are temporally arranged as they happen one after another along observers’ worldlines. There is no unique global passage but a multiplicity of local passages of time. After setting out this positive argument for relationism, (...) the author deals with five common objections to it: (a) triviality of deflationary passage, (b) a-directionality of passage, (c) the impossibility of experiencing passage, (d) fictionalism about passage, and (e) the incompatibility of passage with perduring objects. (shrink)

This book presents a novel metaphysics of concrete entities. The author uses the theory developed to address three major topics in the metaphysics of concreta: fundamentality, persistence over time, and phenomenal consciousness. The book provides a new theory of what "bundles" particular property instances, or tropes, into material property bearers. The theory is based on two new ideas. The first is that the primitive nature of one sui generis monadic property called markedness bears on the bundling of other properties' tropes. (...) The second idea is that the geometric and topological features of a given markedness trope help to determine which tropes it bundles. The author argues that this new markedness bundle theory determines all property co-instantiation at the levels of both type and token, positioning markedness tropes as the fundamental concreta. The theory also explains bundling across time, yielding an advantageous account of material persistence. Finally, markedness tropes operate as de facto panprotopsychist property instances: fundamental non-consciousness tropes that uniquely explain where and why consciousness properties are exemplified. The book solidifies the case for markedness through sustained critical analysis of competing theories of fundamentality and persistence, focusing in part on their inability to account for unending mereological and plural structures. Concrete Particulars will appeal to scholars and advanced students working in metaphysics and philosophy of mind. (shrink)

The metaphysics of quantum gravity explores metaphysical issues related to research programs in theoretical physics clustered under the term quantum gravity. These research programs aim at the formulation of a theory that reconciles the theory of general relativity with quantum theory. The goal is not necessarily to come up with a unified single theory but, more pragmatically, to describe phenomena with a dual nature, embodying both quantum and relativistic features—such as black holes and the early universe. -/- Approaches to quantum (...) gravity are not yet fully worked-out theories. Nevertheless, they already provide a certain partial understanding of physical reality in different ways. Remarkably, they do so with a striking similarity: they virtually all deny the existence of some features usually regarded as essential to the existence of spacetime (or space and/or time) such as its four-dimensionality, the existence of distances and durations between events, or even the very partial ordering of events. -/- This observation is particularly noteworthy, considering the pervasive influence of spatial and temporal organisation on the human mind across various facets of daily life and theoretical thinking, ranging from most ancient religions to contemporary scientific worldviews. The metaphysics of quantum gravity takes as its starting point the puzzling observation that physics could teach us that space and time are not fundamental. It draws on resources from traditional metaphysics to tackle a set of issues related to the possible non-fundamentality of spacetime, and it investigates its potential implications for venerable traditional issues in metaphysics. -/- The metaphysics of quantum gravity is a relatively small and new research field, and thus as of now, its focus has been on explaining how spacetime could emerge from a more fundamental and non-spatiotemporal ontology. Consequently, this article is equally focused on questions regarding the status of spacetime and the emergence of spacetime. Section 1 situates the field within metaphysics of science more broadly. Sections 2 and 3 investigate, respectively, the status of spacetime in different approaches to quantum gravity and a number of potential issues with its lack of fundamentality. The article then covers the nature of the emerging spatiotemporal ontology (Section 4) and the building relation that relates it to the underlying non-spatiotemporal ontology (Section 5). Section 6 surveys various potential applications of spacetime emergence to a number of debates in metaphysics. (shrink)

While there is considerable disagreement on the precise nature of material objecthood, it is standardly assumed that material objects must be spatial. In this paper, I provide two arguments against this assumption. The first argument is made from largely a priori considerations about modal plenitude. The possibility of non-spatial material objects follows from commitment to certain plausible principles governing material objecthood and plausible principles regarding modal plenitude. The second argument draws from current philosophical discussions regarding theories of quantum gravity and (...) the emergence of spacetime. When it is appreciated what possible worlds these current theories commit us to, the possibility of non-spatial material objects will follow. Thus, either route will lead us to the possibility of non-spatial material objects. The significance of this result is that we need to revise our accounts of material objecthood to both accommodate these possibilities and the theories that lead to them. (shrink)

Recent work in quantum gravity has prompted a re-evaluation of the fundamental nature of spacetime. Spacetime is potentially emergent from non-spatiotemporal entities posited by a theory of quantum gravity. Recent efforts have sought to interpret the relationship between spacetime and the fundamental entities through a mereological framework. These frameworks propose that spacetime can be conceived as either having non-spatiotemporal entities as its constituents or being a constituent part of a non-spatiotemporal structure. I present a roadmap for those interested in exploring (...) the role of composition in understanding the emergence of spacetime. I establish a taxonomy based on four crucial parameters that should be considered when constructing potential mereological models. Subsequently, I connect these models to a spectrum of perspectives found in current literature, with the aim of pinpointing areas that require further exploration. Finally, I identify three potential challenges facing mereological models of spacetime emergence, rooted in issues of mereological harmony, the distinction between continuous and discrete spacetime, and the implications of quantum superposition. (shrink)

The concept of location—of something being located at, or occupying, a region or a place—has been an important topic of philosophical investigation over the past fifteen years or so. Yet all the theories of location that have been put forward so far are unsatisfactory, because they fail to have the conceptual resources to describe certain basic locational phenomena. I introduce and partly develop a novel theory of location that does better in this respect than its predecessors. Its most distinctive feature (...) is the way in which it handles so-called cases of multilocation: according to the theory, objects capable of being multilocated occupy regions via proxies, and—in a slogan, and very roughly—to be multilocated is to have several proxies located at different regions. (shrink)

Eternalism is a metaphysical view regarding the nature of time. It posits the equal existence of all times: the past, the present, and the future. Every event, from the big bang to the heat death of the universe, including our births and deaths, is equally real. -/- Under standard eternalism, temporal locations are somewhat akin to spatial locations. No place is exclusively real. When someone says that they stand ‘here’, it is clear that the term ‘here’ refers to their position. (...) ‘Back’ and ‘front’ exist as well. Eternalists stress that ‘now’ is indexical in a similar way. It is equally real with ‘past’ and ‘future’. Events are classified as past, present, or future from some perspective. -/- Eternalism is contrasted with presentism, which maintains that only present things exist and with the growing block view (also known as possibilism or no-futurism), which holds that past and present things exist but not future ones. The moving spotlight view suggests that all times exist but that the present is the only actual time. This view can be termed eternalist, but it preserves a non-perspectival difference between past, present, and future by treating tense as absolute. Additionally, the moving spotlight view retains some characteristics of presentism by maintaining that the ‘now’ is unique and privileged. -/- Broadly speaking, presentism is a common-sensical view, and so aligns with our manifest image of time. This view is, however, at odds with the scientific image of time. The primary motivation for eternalism arises from orthodox interpretations of the theories of relativity. According to them, simultaneity is relative, not absolute. This implies that there is no universal ‘now’ stretched out across the entire universe. One observer’s present can be another’s past or future. Assuming the universe is four-dimensional spacetime, then all events exist unconditionally. -/- The classical argument for eternalism was devised in the 1960s by Rietdijk in 1966 and Putnam in 1967, with subsequent follow-ups by Maxwell in 1985, Penrose in 1989, and Peterson and Silberstein in 2010. This argument and its ramifications remain the subject of ongoing debate. They shall be further explored in this entry, including their relation to other issues in the metaphysics of time and the philosophy of physics. (shrink)

Recent work at the intersection of physics and philosophy of time suggests that time’s absence from theories of quantum gravity (QG) entails that reality is fundamentally atemporal and that time is emergent. I consider two potential ways that time might be emergent: in a robust, dualist sense and in a systemic, physical sense. I examine what each of these possibilities would entail for substantivalist and relationist views of time. I also examine what is meant by ‘fundamental’ when it is said (...) that time’s absence from QG makes reality ‘fundamentally’ atemporal. I argue that there are four senses of ‘fundamental’ at play and although time’s absence from QG precludes it from being fundamental in all four senses, time may still be fundamental in two important ways. A consequence of this clarification of senses of ‘emergence’ and ‘fundamentality’ is that time may be both emergent and fundamental (in some sense). In particular, I propose that time is part of an emergent structure that is foundational for things with macro-level existence. (shrink)