ALT ABSTRACT. There is a widely held view on measurement inferences that defends the prohibition that we should not make inferences from averages taken with ordinal scales (versus quantitative scales; interval or ratio). This prohibition is general—applying to all ordinal scales—and is sometimes endorsed without qualification. Adhering to it dramatically limits research in the social and biomedical sciences. I provide a Bayesian analysis of this problem, determining when measurements from ordinal scales can be used to confirm hypotheses about relative group averages. I illustrate with the alleged paradigm ordinal scale—the Mohs scale of mineral hardness—arguing that it has been mischaracterized in the literature. The prohibition, I conclude, cannot be upheld, even in a qualified sense. The beliefs needed to make average comparisons are less demanding than those appropriate for quantitative scales.

ALT ABSTRACT. When they agree on which data streams are algorithmically random, two Bayesian agents beginning the learning process with different priors may be seen as having compatible beliefs about the global uniformity of nature. This is because the algorithmically random data streams are of necessity globally regular: they are precisely the sequences that satisfy certain important statistical laws. By virtue of agreeing on which data streams are algorithmically random, two Bayesian agents can thus be taken to concur on which global regularities they expect to see in the data. I show that this type of compatibility between priors suffices to ensure that two computable Bayesian agents will reach inter-subjective agreement with increasing information. Thus, when shared by computable Bayesian learners with different subjective priors, the beliefs about uniformity captured by algorithmic randomness provably lead to merging of opinions.

ALT ABSTRACT. There are two important traditions in the philosophy of induction. According to one, inductive arguments are warranted by rules. Bayesianism is the most popular view within this tradition. According to the other, inductive arguments are not warranted by rules but by matters of fact. Norton’s material theory of induction is one such influential view within this tradition. Despite their limitations, both approaches illuminate important aspects inductive support. Here I present a hybrid theory of induction, in which I acknowledge and articulate the role of both rules and matters of fact in our understanding. Rules of induction accurately describe relations of inductive support when they are warranted, and a rule of induction is warranted if the right facts about the matter of the induction obtain. This provides a functional and accurate account of inductive support that can make sense of how different rules of induction coexist and tackle problems in epistemology.

ALT ABSTRACT. There are two kinds of quantum fluctuations relevant to cosmology that we focus on here: those that form the seeds for structure formation in the early universe and those giving rise to Boltzmann brains in the late universe. Boltzmann brains are random agglomerates of particles that, by extreme coincidence, form functioning brains. Unlikely as these coincidences are, they seem to be predicted to occur in a quantum universe as vacuum fluctuations if the universe continues to exist for an infinite (or just very long) time. Indeed, they are predicted to occur over and over, forming the majority of all brains in the history of the universe. We provide an introduction to the Bohmian version of quantum theory and explain why in this version, the undesirable kind of fluctuation leading to Boltzmann brains does not occur (or at least not often), while the desirable kind of fluctuation responsible for structure formation in the early universe does.

ALT ABSTRACT. Biochemists commonly ascribe functions to biomolecules and classify them accordingly, as has been noted in the recent literature on biochemical kinds. But while a lot has been written on biological and psychological functions, less has been said about biochemical functions. I consider whether a biological or a chemical understanding of function can be applied to biochemical functions, illustrating the issue with the example of vitamin B12. I argue that an adequate characterization of biochemical function cannot be provided by either a biological or a chemical understanding alone. Instead, I argue that if we accept functional attribution to biochemical molecules, then biochemical function is constituted by chemical dispositional properties that causally contribute to selected biological processes.

ALT ABSTRACT. Weyl famously argued that if space were discrete, then Euclidean geometry could not hold even approximately. Since then, many philosophers have responded to this argument by advancing alternative accounts of discrete geometry that recover approximately Euclidean space. However, they have missed an importantly flawed assumption in Weyl’s argument: physical geometry is determined by fundamental spacetime structures independently from dynamical laws. In this article, I aim to show its falsity through two rigorous examples: random walks in statistical physics and quantum mechanics.

ALT ABSTRACT. Episodic and semantic memory are often taken to be distinct mental systems, and philosophers often treat episodic memory in isolation from semantic memory. I challenge this assumption, putting pressure on approaches that take episodic memory as a stand-alone topic. I present and systematize psychological and neuroscientific theories of semanticization, namely, that memory content tends to drift from episodic to semantic structure over time and through exposure to an environment. Semanticization, I argue, is a long-term interconnection between episodic and semantic systems that requires approaching both the content and function of these two systems as a whole. Thus we have a reason to reject projects that aim to carve out a uniquely episodic memory content or to pair episodic memory to its own unique function. Instead, seeing declarative memory as a single system with two facets or even a continuum of features allows for deeper insight into both content and function.

ALT Table of Contents Semanticization Challenges the Episodic–Semantic Distinction By Sara Aronowitz Why the Weyl Tile Argument Is Wrong By Lu Chen Biochemical Functions By Francesca Bellazzi The Bohmian Approach to the Problems of Cosmological Quantum Fluctuations By Sheldon Goldstein, Ward Struyve and Roderich Tumulka Hybrid Theory of Induction By Adrià Segarra Bayesian Merging of Opinions and Algorithmic Randomness By Francesca Zaffora Blando Against Prohibition (or When Using Ordinal Scales to Compare Groups Is OK) By Cristian Larroulet Philippi Are We in a Sixth Mass Extinction? The Challenges of Answering and Value of Asking By Federica Bocchi, Alisa Bokulich, Leticia Castillo Brache, Gloria Grand-Pierre and Aja Watkins A Falsificationist Account of Artificial Neural Networks By Oliver Buchholz and Eric Raidl General-Purpose Institutional Decision-Making Heuristics: The Case of Decision-Making under Deep Uncertainty By David Thorstad The Typical Principle By Isaac Wilhelm

ALT ABSTRACT. This article redefines background independence through a gauge-theoretic lens, arguing that it is not exclusive to general relativity but inherent to any gravitational theory whose spacetime geometry emerges dynamically from gauging symmetry groups' algebras. Applying this framework, we demonstrate that (torsional) Newton–Cartan and Carrollian gravities—obtained via gauging the Bargmann and Carroll algebras, respectively—satisfy background independence. This shows that background independence is decoupled from relativistic structures (for example, Lorentzian metrics, light cones) and instead is a hallmark of gauging: spacetime geometry arises as an interacting dynamical gauge field. We also suggest that this new way of thinking about background independence might have relevant implications for quantum gravity theory building.

ALT ABSTRACT. Citizen science involves collaboration between citizens and researchers. Just as is the case with scientific inquiry among trained researchers alone, both epistemic and non-epistemic values can conflict with one another within citizen science. When this happens, philosophers of science have sought to manage the various values of researchers and other stakeholders. I consider two approaches for addressing these conflicts: the transparency model and the unanimous consent model. While proponents of the former suggest that difficulties implementing this approach will be faced by both citizens and researchers, I argue that they are likely amplified in the case of citizen science: citizens face greater difficulties than researchers in making explicit other interpretations of data and clarifying major assumptions that were made, two steps of the transparency approach. Instead, I propose that the unanimous consent model be adopted to manage values in citizen science.

ALT ABSTRACT. In the Hamiltonian formalism, a gauge transformation is typically defined as a transformation generated by an arbitrary combination of first-class constraints. But gauge transformations are also understood as marking physical equivalence: they relate states or solutions that represent the same physical situation. Whether these two characterizations coincide has been a matter of debate. Pitts, for example, contends that first-class constraints can generate a 'bad physical change'. This article defends the standard view, arguing that it correctly identifies both states and solutions that are equivalent from the perspective of the geometric structure of the Hamiltonian formalism. In doing so, it clarifies the relationship between mathematical and interpretational perspectives on gauge transformations.

ALT ABSTRACT. Modified Newtonian dynamics (MOND) is a framework of theories that adjust Newton's laws of gravity to explain effects such as galactic rotation anomalies, offering an alternative to dark matter. We examine the justification of MOND by assessing its relationship to established theories, in particular its connection to Newtonian gravitation. We argue that MOND fails a key condition for a theory's justification—'reduction-wise justification'—as it does not adequately reduce to Newtonian gravity in a fully non-arbitrary way. This case study provides crucial results for the debate on inter-theoretic reduction: MOND's failure as a case of reduction highlights limits to standard accounts of limiting reduction. We respond with a refined framework that introduces two additional criteria to better distinguish successful from pathological reductions, showing how analysing reduction-wise justification allows us to evaluate the validity of novel theories not yet empirically established.

ALT ABSTRACT. I argue that the singular structure of spacetime is best conceptualized as an extrinsic, non-local, but localizable, property of spacetime regions (of any size), and that there is no unique, best definition of a singular region of spacetime. There is, however, a schema that any adequate definition instantiates. Moreover, the question of what kind of incomplete curves witness singular structure is intimately connected to the question of what kind of curves represent possible trajectories of observers in physically reasonable motion.