Sam Baron

It is plausible that the models of scientific theories correspond to possibilities. But how do we know which models of which scientific theories so correspond? This paper provides a novel proposal for guiding belief about possibilities via scientific theories. The proposal draws on the notion of an effective theory: a theory that applies very well to a particular, restricted domain. We argue that it is the models of effective theories that we should believe correspond, at least in part, to possibilities. It is thus effective theories that should guide modal reasoning in science.

Recent work in quantum gravity (QG) suggests that spacetime is not fundamental. Rather, spacetime emerges from an underlying non-spatiotemporal reality. Spacetime functionalism has been proposed as one way to make sense of the emergence of spacetime. However, spacetime functionalism faces a ‘collapse’ problem. The functionalist analysis seems to force spacetime into the (more) fundamental ontology of QG, thereby conflicting with—rather than elucidating—spacetime emergence. In this paper, I show how to resolve the collapse problem. The solution is to draw on an existing distinction between physical and metaphysical notions of (relative) fundamentality. Using this distinction, we can see that spacetime functionalism does not after all force spacetime into the (more) fundamental ontology of QG in any troubling sense. Along the way, I suggest how to extend this solution to similar collapse problems in other domains.

Recent work in quantum gravity (QG) suggests that spacetime is not fundamental. Rather, spacetime emerges from an underlying non-spatiotemporal reality. Spacetime functionalism has been proposed as one way to make sense of the emergence of spacetime. However, spacetime functionalism faces a ‘collapse’ problem. The functionalist analysis seems to force spacetime into the (more) fundamental ontology of QG, thereby conflicting with—rather than elucidating—spacetime emergence. In this paper, I show how to resolve the collapse problem. The solution is to draw on an existing distinction between physical and metaphysical notions of (relative) fundamentality. Using this distinction, we can see that spacetime functionalism does not after all force spacetime into the (more) fundamental ontology of QG in any troubling sense. Along the way, I suggest how to extend this solution to similar collapse problems in other domains.

Some philosophers argue that in order to accommodate a range of our practices we must suppose that causation is not an all or nothing matter: it comes in degrees. We argue for two key claims. First, we can accommodate these practices without positing degree theoretic causation, and we can do so by appealing to various things that clearly do admit of degrees. So, positing causation by degree is unnecessary. Second, not only is positing degree theoretic causation unnecessary, but in fact there is no single thing, causation by degree, that could play the role required of it if it is to accommodate these practices. Thus, we conclude, there is no motivation to posit degree theoretic causation that arises from consideration of these practices.

We provide a reply to the Argument from Intimacy on behalf of defenders of emergent spacetime in theories of quantum gravity. We argue that if one accepts that spacetime regions are nowhere in the sense that they are locations but do not have locations, then the Argument from Intimacy can be resolved. We go on to consider a problem with this response, namely that it is unavailable to super-substantivalists. We argue that this is right for identity but not priority super-substantivalists. We then suggest that there is no cost for our solution here, since identity versions of super-substantivalism face severe challenges in the context of spacetime emergence and so should be rejected anyway.

ABSTRACT Strong non-maximalism holds that some truths require no ontological ground of any sort. Strong non-maximalism allows one to accept that some propositions are true without being forced to endorse any corresponding ontological commitments. We show that there is a version of truthmaker theory available – anti-aboutness truthmaking – that enjoys the dialectical benefits of the strong non-maximalist’s position. According to anti-aboutness truthmaking, all truths require grounds, but a proposition need not be grounded in the very thing(s) that the proposition is about. We argue that if strong non-maximalism can be defended, then so can anti-aboutness truthmaking on the very same basis; one can enjoy the benefits of strong non-maximalism without giving up on the idea that truth is always grounded in being.

This article motivates and develops a new theory of time: priority presentism. Priority presentism is the view according to which (i) only present entities exist fundamentally and (ii) past and future entities exist, but they are grounded in the present. The articulation of priority presentism is an exercise in applied grounding: it draws on concepts from the recent literature on ontological dependence and applies those concepts in a new way, to the philosophy of time. The result, as I will argue, is an attractive position that can do much of the same work in satisfying our intuitions about time as presentism, but without the ontological cost.

According to conventionalist accounts of personal identity, persons are constituted in part by practices and attitudes of certain sorts of care. In this paper, we concentrate on the most well‐developed and defended version of conventionalism currently on offer (namely, that proposed by David Braddon‐Mitchell, Caroline West, and Kristie Miller) and discuss how the conventionalist appears forced either (1) to accept arbitrariness concerning from which perspective to judge one's survival or (2) to maintain egalitarianism at the cost of making “transfiguring” decisions such as Pascal's Wager rationally intractable. We consider three ways the egalitarian conventionalist could make these choices tractable and show that each one comes at significant cost to the view. We end the paper by considering whether accepting arbitrariness would be a better move for the conventionalist and conclude that, even here, she runs the risk of transfiguring choices being rationally intractable.

Causal Set Theory (CST) is a promising approach to fundamental physics that seems to treat causation as a basic posit. But in exactly what sense is CST causal? We argue that if the growth dynamics is interpreted as a physical process, then CST employs relations of actual causation between causal set elements, whereby elements bring one another into existence. This is important, as it provides a better sense of how CST works, highlights important differences from general relativity---where relations between spacetime points are typically seen as cases of mere causal connectibility rather than actual causation of the relevant type---and points toward a specific understanding of the emergence of spacetime within CST.

There has been a surge of interest in explainable artificial intelligence (XAI). It is commonly claimed that explainability is necessary for trust in AI, and that this is why we need it. In this paper, I argue that for some notions of trust it is plausible that explainability is indeed a necessary condition. But that these kinds of trust are not appropriate for AI. For notions of trust that are appropriate for AI, explainability is not a necessary condition. I thus conclude that explainability is not necessary for trust in AI that matters.

Recent work in quantum gravity (QG) suggests that spacetime is not fundamental. Rather, spacetime emerges from an underlying non-spatiotemporal reality. Spacetime functionalism has been proposed as one way to make sense of the emergence of spacetime. However, spacetime functionalism faces a ‘collapse’ problem. The functionalist analysis seems to force spacetime into the (more) fundamental ontology of QG, thereby conflicting with—rather than elucidating—spacetime emergence. In this paper, I show how to resolve the collapse problem. The solution is to differentiate between physical and metaphysical notions of (relative) fundamentality. With this distinction in hand, we can see that spacetime functionalism does not after all force spacetime into the (more) fundamental ontology of QG in any troubling sense. A side benefit of the paper is that it provides a sharpened characterisation of various notions of (relative) fundamentality.

There has been a recent surge of interest in the idea that spacetime is not fundamental. Much of this interest has focused on the implications for physics. There has been less work investigating the implications of spacetime emergence for existing theories in metaphysics. This paper aims to fill this gap by considering the impact of spacetime emergence on priority monism. We argue that one prominent version of priority monism is incompatible with spacetime emergence. We go on to present a solution to this problem, which involves rethinking the nature of concreteness. This leads to a new version of priority monism that is compatible with emergent spacetime.

The apparent downsides of opaque algorithms has led to a demand for explainable AI (XAI) methods by which a user might come to understand why an algorithm produced the particular output it did, given its inputs. Patients, for example, might find that the lack of explanation of the process underlying the algorithmic recommendations for diagnosis and treatment hinders their ability to provide informed consent. This paper examines the impact of two factors on user perceptions of explanations for AI systems in medical contexts. The factors considered were the stakes of the decision—high versus low—and the decision source—human versus AI. 484 participants were presented with vignettes in which medical diagnosis and treatment plan recommendations were made by humans or by AI. Separate vignettes were used for high stakes scenarios involving life-threatening diseases, and low stakes scenarios involving mild diseases. In each vignette, an explanation for the decision was given. Four explanation types were tested across separate vignettes: no explanation, counterfactual, causal and a novel ‘narrative-based’ explanation, not previously considered. This yielded a total of 16 conditions, of which each participant saw only one. Individuals were asked to evaluate the explanations they received based on helpfulness, understanding, consent, reliability, trust, interests and likelihood of undergoing treatment. We observed a main effect for stakes on all factors and a main effect for decision source on all factors except for helpfulness and likelihood to undergo treatment. While we observed effects for explanation on helpfulness, understanding, consent, reliability, trust and interests, we by and large did not see any differences between the effects of explanation types. This suggests that the effectiveness of explanations may not depend on type of explanation but instead, on the stakes and decision source.

Many philosophers have thought that our folk, or pre-reflective, view of persistence is one on which objects endure. This assumption not only plays a role in disputes about the nature of persistence itself, but is also put to use in several other areas of metaphysics, including debates about the nature of change and temporal passage. In this paper, we empirically test three broad claims. First, that most people (i.e. most non-philosophers) believe that, and it seems to them as though, objects persist by enduring rather than perduring. Second, that most people have a view of change on which enduring but not perduring objects count as changing. Third, that one reason why the folk represent time as dynamical is because it seems to them, and they believe that, they endure through time. We found no evidence to support these claims. While there are certainly plenty of ‘folk’ endurantists in the population we tested, there are also plenty of ‘folk’ perdurantists. We did not find robust evidence that a majority of people believed that, or it seemed to them as though, objects endure rather than perdure. We conclude that many arguments in favour of endurantism that appeal to folk beliefs about, or experiences of, persisting objects and change rest on views about those beliefs and experiences that are empirically unsupported. There is no evidence to suggest that endurantism is the folk friendly view of persistence, and so we should stop treating it as such without argument.

This paper addresses the extent to which both Julian Barbour‘s Machian formulation of general relativity and his interpretation of canonical quantum gravity can be called timeless. We differentiate two types of timelessness in Barbour‘s (1994a, 1994b and 1999c). We argue that Barbour‘s metaphysical contention that ours is a timeless world is crucially lacking an account of the essential features of time—an account of what features our world would need to have if it were to count as being one in which there is time. We attempt to provide such an account through considerations of both the representation of time in physical theory and in orthodox metaphysical analyses. We subsequently argue that Barbour‘s claim of timelessness is dubious with respect to his Machian formulation of general relativity but warranted with respect to his interpretation of canonical quantum gravity. We conclude by discussing the extent to which we should be concerned by the implications of Barbour‘s view.

Many prominent critiques of philosophical methods proceed by suggesting that some method is unreliable, especially in comparison to some alternative method. If one agrees with these critiques, it may seem natural to conclude that these (comparatively) unreliable methods should be abandoned. Drawing upon work on the division of cognitive labour in science, we argue that things are not so straightforward. Rather, whether an unreliable method should be abandoned depends heavily on the crucial question of how we should divide philosophers’ time and effort between different methods in order to maximize our prospects of achieving epistemic success. We show that, in a range of cases, even a (comparatively) unreliable method may deserve to be allocated some of these resources.

According to dialetheism, there are some true contradictions. According to the A-theory, the passage of time is a mind-independent feature of reality. On some A-theories, the passage of time involves the movement of the present. I show that by appealing to dialetheism one can explain why the present moves. I then argue that A-theorists should adopt this explanation. To do this, I defend two claims. First, that the dialetheic explanation is an improvement on the only other explanation available for why the present moves and, second, that adopting the explanation is better than leaving the motion of the present unexplained. Assuming that A- theorists should adopt the best available version of their view, it follows that they should adopt a dialetheic explanation of why time passes.

I introduce an argument for Platonism based on intra-mathematical explanation: the explanation of one mathematical fact by another. The argument is important for two reasons. First, if the argument succeeds then it provides a basis for Platonism that does not proceed via standard indispensability considerations. Second, if the argument fails, it can only do so for one of the three reasons: either because there are no intra-mathematical explanations, or because not all explanations are backed by dependence relations, or because some form of noneism—the view according to which non-existent entities possess properties and stand in relations—is true. The argument thus forces a choice between nominalism without noneism, intra-mathematical explanation, and a backing conception of explanation. You can have any two, but not all three.

In this paper, we explore locative grounding harmony, according to which the location of the grounds mirrors the location of the grounded. We proceed in three stages. First, we clarify the notion of locative harmony and describe different locative harmony principles. Second, we offer two arguments for the claim that grounding between physically located entities obeys principles of locative harmony. Third, we consider and respond to a range of cases that seem to show that grounding relations between physically located entities do not obey such principles. We conclude that grounding between such entities obeys locative harmony.

Many philosophers have thought that our folk, or pre-reflective, view of persistence is one on which objects endure. This assumption not only plays a role in disputes about the nature of persistence itself, but is also put to use in several other areas of metaphysics, including debates about the nature of change and temporal passage. In this paper, we empirically test three broad claims. First, that most people (i.e. most non-philosophers) believe that, and it seems to them as though, objects persist by enduring rather than perduring. Second, that most people have a view of change on which enduring but not perduring objects count as changing. Third, that one reason why the folk represent time as dynamical is because it seems to them, and they believe that, they endure through time. We found no evidence to support these claims. While there are certainly plenty of ‘folk’ endurantists in the population we tested, there are also plenty of ‘folk’ perdurantists. We did not find robust evidence that a majority of people believed that, or it seemed to them as though, objects endure rather than perdure. We conclude that many arguments in favour of endurantism that appeal to folk beliefs about, or experiences of, persisting objects and change rest on views about those beliefs and experiences that are empirically unsupported. There is no evidence to suggest that endurantism is the folk friendly view of persistence, and so we should stop treating it as such without argument.

Philosophical accounts denying that temporal passage is an objective feature of reality face an explanatory challenge with respect to why it appears to us as though time passes. Recently, two solutions have surfaced. Cognitive illusionism claims that people experience the passage of time due to their belief that time passes. Cognitive error theory claims that we do not experience the passage of time, but hold the belief that we do, which we have acquired through making an inference from the prior belief that time passes. These approaches suppose that belief and passage experience are explanatorily connected, and they depend on the claims that people who experience the passage of time or at least believe that they do also believe that time passes. To test these claims, we probed the beliefs of populations of individuals with depression and schizotypy, thus conditions that are strongly associated with alterations in temporal phenomenology. Depression was assessed with the Beck Depression Inventory (BDI) and schizotypy with the short Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE). While cognitive illusionism and inferentialist cognitive error theory would predict a strong association between BDI and O-LIFE scores and beliefs about time passage, our study found no such association. The experience of passage does not seem to be explanatorily connected to beliefs about the passage of time.

A number of approaches to quantum gravity (QG) seem to imply that spacetime does not exist. Philosophers are quick to point out, however, that the loss of spacetime should not be regarded as total. Rather, we should interpret these approaches as ones that threaten the fundamentality but not the existence of spacetime. In this paper, I argue for two claims. First, I argue that spacetime realism is not forced by QG; spacetime eliminativism remains an option. Second, I argue that eliminativism provides a useful framework for developing two existing approaches to the metaphysics of QG, involving functionalism and mereology respectively.

Recent discussion of the problem of negative existentials for truthmaker theory suggests a modest solution to the problem: fully general negative truths like do not require truthmakers, whereas partially general negative truths like do. This modest solution provides a third alternative to the two standard solutions to the problem of negative existentials: the endorsement of truthmaker gaps, and the appeal to contentious ontological posits. We argue that this modest, middle-ground position is inconsistent with certain plausible general principles for truthmaking. The only stable positions are to treat all negative truths as requiring truthmakers, or admit that no negative truths require truthmakers. Along the way, we explore some previously unaddressed questions for nonmaximalist truthmaker theory.