Bell’s Theorem from Physics 36:1–28 (1964) and the (Strong) Free Will Theorem of Conway and Kochen from Notices AMS 56:226–232 (2009) both exclude deterministic hidden variable theories (or, in modern parlance, ‘ontological models’) that are compatible with some small fragment of quantum mechanics, admit ‘free’ settings of the archetypal Alice and Bob experiment, and satisfy a locality condition akin to parameter independence. We clarify the relationship between these theorems by giving reformulations of both that exactly pinpoint their resemblance and their (...) differences. Our reformulation imposes determinism in what we see as the only consistent way, in which the ‘ontological state’ initially determines both the settings and the outcome of the experiment. The usual status of the settings as ‘free’ parameters is subsequently recovered from independence assumptions on the pertinent (random) variables. Our reformulation also clarifies the role of the settings in Bell’s later generalization of his theorem to stochastic hidden variable theories. (shrink)

Prefatory. The Logic of Theism .–Our world, the thing or complex of things, which is continuous and co-ordinate with our present perception, is self-transcendent. The proof is from observation, from our reactions, which are often more sensitive than our direct observations, from the testimony of philosophers, expert psychologists, and poets . To say that our world is self-transcendent is to say that it presents itself to our minds as indigent of some sort of supplement or complement having some sort of (...) ontological status which it implies in some capacity. The problem of the Logic of Theism is the problem of determining, assigning a definite value to, these “somes.” In other words, the proof of God is the proof that what “our world implies” when it is made determinate corresponds with the received conception of God in such a way as to justify the substitution of the name God for the indication “what our world implies.”. (shrink)

Inquiry, Volume 57, Issue 1, Page 55-96, February 2014.

Whole Brain Emulation has been championed as the most promising, well-defined route to achieving both human-level artificial intelligence and superintelligence. It has even been touted as a viable route to achieving immortality through brain uploading. WBE is not a fringe theory: the doctrine of Computationalism in philosophy of mind lends credence to the in-principle feasibility of the idea, and the standing of the Human Connectome Project makes it appear to be feasible in practice. Computationalism is a popular, independently plausible theory, (...) and Connectomics a well-funded empirical research program, so optimism about WBE is understandable. However, this optimism may be misplaced. This article argues that WBE is, at best, no more compelling than any of the other far-flung routes to achieving superintelligence. Similarly skeptical conclusions are found regarding immortality. The essay concludes with some positive considerations in favor of the Biological Theory of consciousness, as well as morals about the limits of Computationalism in both artificial intelligence and the philosophy of mind more generally. (shrink)

Even though Kant’s theory of cognition (Erkenntnis) is central to his Critique of Pure Reason, it has rarely been asked what exactly Kant means by the term “cognition”. Against the widespread assumption that cognition (in the most relevant sense of that term) can be identified with knowledge or if not, that knowledge is at least a species of cognition, we argue that the concepts of cognition and knowledge in Kant are not only distinct, but even disjunct. To show this, we (...) first (I) investigate Kant’s explicit characterizations of the nature of cognition. As it turns out, he introduces several different notions that must be carefully distinguished before identifying the one that is central to his project in the first Critique. We then (II) consider the basic features of Kant’s conception of knowledge, indicating both how it involves assent and objective justification and how it relates to our contemporary conception. Next (III), we compare and contrast Kant’s understanding of cognition and his conception of knowledge in a way that allows us to present their fundamental differences and connections. We argue that while cognition, in the most relevant sense, is a species of representation that differs from other representations in that it involves the conceptual determination of a sensibly given object, knowledge (for Kant) is a kind of assent to a judgment that requires consciousness of a sufficient epistemic ground. Finally (IV), by appreciating the differences between cognition and knowledge, we explain several of the implications this conception of cognition has for some of Kant’s main claims in the Critique of Pure Reason as a whole. Among other things, we show how Kant can deny cognition of specific things in themselves while allowing philosophical knowledge about things in themselves in general (e.g. that they exist, are not in space and time, etc.). (shrink)

The properties colored and red stand in a special relation. Namely, red is a determinate of colored, and colored is determinable relative to red. Many other properties are similarly related. The determination relation is an interesting topic of logical investigation in its own right, and the prominent philosophical inquiries into this relation have, accordingly, operated at a high level of abstraction.1 It is time to return to these investigations, not just as a logical amusement, but for the payoffs such investigation (...) can yield in solving some basic metaphysical problems. The goal in what follows is twofold. First, I argue for a novel understanding of the determination relation. Second, this understanding is applied to yield insights into property instance (e.g., trope) individuation, how different property types can share an instance, the relation between property types and property instances, as well as applications to causation (mental causation, in particular). (shrink)

From the time of Locke, discussions of personal identity have often ignored the question of our basic metaphysical nature: whether we human people are biological organisms, spatial or temporal parts of organisms, bundles of perceptions, or what have you. The result of this neglect has been centuries of wild proposals and clashing intuitions. What Are We? is the first general study of this important question. It beings by explaining what the question means and how it differs from others, such as (...) questions of personal identity and the mind-body problem. It then examines in some depth the main possible accounts of our metaphysical nature, detailing both their theoretical virtues and the often grave difficulties they face. The book does not endorse any particular account of what we are, but argues that the matter turns on more general issues in the ontology of material things. If composition is universal--if any material things whatever make up something bigger--then we are temporal parts of organisms. If things never compose anything bigger, so that there are only mereological simples, then we too are simples--perhaps the immaterial substances of Descartes--or else we do not exist at all (a view Olson takes very seriously). The intermediate view that some things compose bigger things and others do not leads almost inevitably to the conclusion that we are organisms. So we can discover what we are by working out when composition occurs. (shrink)

“What is the structure of thought?” is as central a question as any in cognitive science. A classic answer to this question has appealed to a Language of Thought (LoT). We point to emerging research from disparate branches of the field that supports the LoT hypothesis, but also uncovers diversity in LoTs across cognitive systems, stages of development, and species. Our letter formulates open research questions for cognitive science concerning the varieties of rules and representations that underwrite various LoT-based systems (...) and how these variations can help researchers taxonomize cognitive systems. (shrink)

Focusing on the breakthrough field of molecular engineering--a new technology enabling scientists to build tiny machines atom by atom--the author offers projections on how this technological revolution will affect the future of computer science, space travel, medicine, and manufacturing.

Beliefs serve at least two broad functions. First, they help us navigate the world. Second, they serve as signals to manipulate others. Philosophers and psychologists have focused on the first function while largely overlooking the second. This article advances a conception of signals and makes a prima facie case for a social signaling function for at least some beliefs. Truth and rational support are often irrelevant to the signaling function. If some beliefs evolved for a signaling function, then we should (...) expect various biases that aid in the manipulation of others. (shrink)

Is it impossible for a person to do something intentionally without knowing that she is doing it? The phenomenon of self-deceived agency might seem to show otherwise. Here the agent is not lying, yet disavows a correct description of her intentional action. This disavowal might seem expressive of ignorance. However, I show that the self-deceived agent does know what she's doing. I argue that we should understand the factors that explain self-deception as masking rather than negating the practical knowledge characteristic (...) of intentional action. This masking takes roughly the following form: when we are deceiving ourselves about what we are intentionally doing, we don't think about our action because it's painful to do so. (shrink)

I develop an account of counterfactual conditionals using “causal models”, and argue that this account is preferable to the currently standard account in terms of “similarity of possible worlds” due to David Lewis and Robert Stalnaker. I diagnose the attraction of counterfactual theories of causation, and argue that it is illusory.

According to one interpretation of Aristotle’s famous thesis, to say that action is the conclusion of practical reasoning is to say that action is itself a judgment about what to do. A central motivation for the thesis is that it suggests a path for understanding the non-observational character of practical knowledge. If actions are judgments, then whatever explains an agent’s knowledge of the relevant judgment can explain her knowledge of the action. I call the approach to action that accepts Aristotle’s (...) thesis so understood Normativism. There are many reasons to doubt Normativism. My aim in this paper is to defend Normativism from a pair of arguments that purport to show that a normative judgment could not constitute an event in material reality and also the knowledge of such a happening. Both highlight a putative mismatch between the natures of, on the one hand, an agent’s knowledge of her normative judgment and, on the other, her knowledge of her own action. According to these objections, knowledge of action includes (a) perceptual knowledge and (b) knowledge of what one has already done. But knowledge of a normative judgment includes neither. Hence knowledge of action cannot simply be knowledge of a normative judgment. (shrink)

We present several quantitative analyses of the prevalence and visibility of women in moral, political, and social philosophy, compared to other areas of philosophy, and how the situation has changed over time. Measures include faculty lists from the Philosophical Gourmet Report, PhD job placement data from the Academic Placement Data and Analysis project, the National Science Foundation's Survey of Earned Doctorates, conference programs of the American Philosophical Association, authorship in elite philosophy journals, citation in the Stanford Encyclopedia of Philosophy, and (...) extended discussion in abstracts from the Philosopher's Index. Our data strongly support three conclusions: (1) Gender disparity remains large in mainstream Anglophone philosophy; (2) ethics, construed broadly to include social and political philosophy, is closer to gender parity than are other fields in philosophy; and (3) women's involvement in philosophy has increased since the 1970s. However, by most measures, women's involvement and visibility in mainstream Anglophone philosophy has increased only slowly; and by some measures there has been virtually no gain since the 1990s. We find mixed evidence on the question of whether gender disparity is even more pronounced at the highest level of visibility or prestige than at more moderate levels of visibility or prestige. -/- . (shrink)

Unconscious logical inference seems to rely on the syntactic structures of mental representations (Quilty-Dunn & Mandelbaum 2018). Other transitions, such as transitions using iconic representations and associative transitions, are harder to assimilate to syntax-based theories. Here we tackle these difficulties head on in the interest of a fuller taxonomy of mental transitions. Along the way we discuss how icons can be compositional without having constituent structure, and expand and defend the “symmetry condition” on Associationism (the idea that associative links and (...) transitions are perfectly symmetric). In the end, we show how a BIT (“bare inferential transition”) theory can cohabitate with these other non-inferential mental transitions. (shrink)

Standard microbial evolutionary ontology is organized according to a nested hierarchy of entities at various levels of biological organization. It typically detects and defines these entities in relation to the most stable aspects of evolutionary processes, by identifying lineages evolving by a process of vertical inheritance from an ancestral entity. However, recent advances in microbiology indicate that such an ontology has important limitations. The various dynamics detected within microbiological systems reveal that a focus on the most stable entities (or features (...) of entities) over time inevitably underestimates the extent and nature of microbial diversity. These dynamics are not the outcome of the process of vertical descent alone. Other processes, often involving causal interactions between entities from distinct levels of biological organisation, or operating at different time scales, are responsible not only for the destabilisation of pre-existing entities, but also for the emergence and stabilisation of novel entities in the microbial world. In this article we consider microbial entities as more or less stabilised functional wholes, and sketch a network-based ontology that can represent a diverse set of processes including, for example, as well as phylogenetic relations, interactions that stabilise or destabilise the interacting entities, spatial relations, ecological connections, and genetic exchanges. We use this pluralistic framework for evaluating (i) the existing ontological assumptions in evolution (e.g. whether currently recognized entities are adequate for understanding the causes of change and stabilisation in the microbial world), and (ii) for identifying hidden ontological kinds, essentially invisible from within a more limited perspective. We propose to recognize additional classes of entities that provide new insights into the structure of the microbial world, namely “processually equivalent” entities, “processually versatile” entities, and “stabilized” entities. (shrink)

De-extinction raises anew ontological and epistemological problems that have engaged environmental philosophers for decades. This essay re-examines these issues to provide a fuller understanding—and a critique—of de-extinction. One of my claims is that de-extinction as a philosophical problem merely recycles old issues and debates in the field (hence, “zombie” arguments). De-extinction is a project that arises out of the assertion of human domination of the natural world. Thus the acceptance of de-extinction as an environmental policy is an expression of a (...) human-nature relationship that disvalues the natural world and subjugates nature completely to the interests of humanity. (shrink)

Aristotle's treatment of the choice between the political and contemplative lives (in EN I 5 and X 7-8) can seem awkward. To offer one explanation of this, I argue that when he invokes self-sufficience (autarkeia) as a criterion for this choice, he appeals to two different and incompatible specifications of "lacking nothing." On one specification, suitable to a human being living as a political animal and thus seeking to realize his end as an engaged citizen of a polis, a person (...) lacks nothing by possessing a wide range of goods that directly require other people. On the other, more suitable to a god or a beast, a person lacks nothing by having no need of goods that directly require other people. The ambiguity of this criterion renders the choice between the political and contemplative lives difficult. (shrink)

There are a variety of topics in the philosophy of science that need to be rethought, in varying degrees, after one pays careful attention to the ways in which computer simulations are used in the sciences. There are a number of conceptual issues internal to the practice of computer simulation that can benefit from the attention of philosophers. This essay surveys some of the recent literature on simulation from the perspective of the philosophy of science and argues that philosophers have (...) a lot to learn by paying closer attention to the practice of simulation. (shrink)

Resource rationality may explain suboptimal patterns of reasoning; but what of “anti-Bayesian” effects where the mind updates in a direction opposite the one it should? We present two phenomena — belief polarization and the size-weight illusion — that are not obviously explained by performance- or resource-based constraints, nor by the authors’ brief discussion of reference repulsion. Can resource rationality accommodate them?

According to a view attractive to both metaphysicians and ethicists, every period in a person’s life is the life of a being just like that person except that it exists only during that period. These “subpeople” appear to have moral status, and their interests seem to clash with ours: though it may be in some person’s interests to sacrifice for tomorrow, it is not in the interests of a subperson coinciding with him only today, who will never benefit from it. (...) Or perhaps there is no clash, and a subperson’s interests derive from those of the person it coincides with. But this makes it likely that our own interests derive from those of other beings coinciding with us. (shrink)

The idea that there is a “Number Sense” (Dehaene, 1997) or “Core Knowledge” of number ensconced in a modular processing system (Carey, 2009) has gained popularity as the study of numerical cognition has matured. However, these claims are generally made with little, if any, detailed examination of which modular properties are instantiated in numerical processing. In this article, I aim to rectify this situation by detailing the modular properties on display in numerical cognitive processing. In the process, I review literature (...) from across the cognitive sciences and describe how the evidence reported in these works supports the hypothesis that numerical cognitive processing is modular. I outline the properties that would suffice for deeming a certain processing system a modular processing system. Subsequently, I use behavioral, neuropsychological, philosophical, and anthropological evidence to show that the number module is domain specific, informationally encapsulated, neurally localizable, subject to specific pathological breakdowns, mandatory, fast, and inaccessible at the person level; in other words, I use the evidence to demonstrate that some of our numerical capacity is housed in modular casing. (shrink)

Nancy Cartwright offers an account of causal powers, and argues that it explains some important general features of scientific method. Patricia Cheng argues that this theory is superior as a psychological theory of learning to standard models of conditioning. I extend and develop the theory, and argue that it provides the best explanation of a number of problem cases for philosophical theories of causation, including preemption, overdetermination and puzzles about transitivity. Hitchcock and Halpern & Pearl on ‘actual causes’ Problems and (...) morals 2.1 Puzzles about prevention 2.2 Counterfactuals Causal powers 3.1 Generative causal power 3.2 Preventative causal power Net and component powers ‘Actual’ or ‘successful’ causes Solutions to puzzle cases Conclusion. (shrink)

How homogenous are the sources of human motivation? Textbook Humeans hold that every human action is motivated by desire, thus any heterogeneity derives from differing objects of desire. Textbook Kantians hold that although some human actions are motivated by desire, others are motivated by reason. One question in this vicinity concerns whether there are states such that to be in one is at once take the world to be a certain way and to be motivated to act: the state-question. My (...) question here is different: whether passion and reason constitute distinct sources of human motivation: the source question. In this essay, I defend an affirmative answer to the source-question while remaining neutral on the state-question. I distinguish between what I call orectic desires, which are associated with the appetites, and anorectic desires, which are associated with judgments of the good. I argue that the two sorts of desires constitute distinct sources of motivation initially on the basis of their differing epistemological profiles. Specifically, self-attributions of anorectic desires are governed by the transparency condition, self-attributions of orectic desires are not. It emerges from this discussion that the motivation for performing an action arises in very different ways from each sort of desire. This difference, in turn, is explained by their differing relations to the will. Roughly, an orectic desire influences the will, but an anorectic desire is the will. The motivation to perform some of our actions derives simply from the determination that they are to-be-done—from reason. (shrink)

It is often hard to articulate a thought. Why should this be, if not that to have a thought is one thing, and to know it something else? In fact the gap between thought and its articulation is not epistemic. While it’s true that we come to know our thoughts better through articulation, it's not because a thought is already perfectly determinate despite my ignorance of it. Rather, we make the thought determinate through articulation. This connection between the determinacy of (...) the thinker’s knowledge of their thought and the determinacy of the thought itself is a mark of thought’s fundamentally first-personal character: what’s beyond the reach of my current powers of articulation cannot be an object of any attitude of mine. (shrink)

Some collective irrationalities, like epistemically and pragmatically reckless Covid skepticism, are especially dangerous. While we normally have incentives to avoid dangerous beliefs, there are cases in which the danger of a belief is valuable. This is not captured by most accounts of motivated reasoning. I argue that Covid skepticism can function as a costly signal (handicap) so as to more effectively communicate social identity and commitment.

By considering carefully Socrates' invocations of 'compulsion' in Plato's Republic, I seek to explain how both justice and compulsion are crucial to the philosophers' decision to rule in Kallipolis, so that this decision does not contradict Socrates' central thesis that it is always in one's interests to act justly. On my account, the compulsion is provided by a law, made by the city's lawgivers, that requires people raised to be philosophers take turns ruling. Justice by itself does not require the (...) philosophers to rule, but it does require them to obey just laws. I also consider the implications of this view for Plato's politics. (shrink)

This paper argues that, despite appearances to the contrary, Kant and contemporary analytic metaphysicians are interested in the same kind of metaphysical dependence relation that finds application in a range of contexts and that is today commonly referred to as grounding. It also argues that comparing and contrasting Kant’s and contemporary metaphysicians’ accounts of this relation proves useful for both Kant scholarship and for contemporary metaphysics. The analyses provided by contemporary metaphysicians can be used to shed light on Kant’s understanding (...) of what a real conditioning relation is, while Kant’s perspective on the practice and goals of metaphysics sheds light on several claims and issues at home in the contemporary debate. (shrink)

We propose that doping be legalized under medical supervision. First, we discuss two motivations for allowing medically supervised doping. We reject the ‘compromised choice/harm minimization’ motivation as unlikely to win the support of athletes. We agree that it could lead to an arms race. Instead, we favor full acceptance of doping under medical supervision and answer Reid’s spirit of sport objection to medical manipulation. After presenting a set of guiding principles, we use them to answer the arms race objection and (...) rebut one of the most prominent objections in the literature about the safety of medically supervised doping, the game-theoretic objection. (shrink)

Theories of number concepts often suppose that the natural numbers are acquired as children learn to count and as they draw an induction based on their interpretation of the first few count words. In a bold critique of this general approach, Rips, Asmuth, Bloomfield [Rips, L., Asmuth, J. & Bloomfield, A.. Giving the boot to the bootstrap: How not to learn the natural numbers. Cognition, 101, B51–B60.] argue that such an inductive inference is consistent with a representational system that clearly (...) does not express the natural numbers and that possession of the natural numbers requires further principles that make the inductive inference superfluous. We argue that their critique is unsuccessful. Provided that children have access to a suitable initial system of representation, the sort of inductive inference that Rips et al. call into question can in fact facilitate the acquisition of larger integer concepts without the addition of any further principles. (shrink)

In _On Empirically Equivalent Systems of the World_ from 1975, Quine formulated a thesis of underdetermination roughly to the effect that every scientific theory has an empirically equivalent but logically incompatible rival, one that cannot be discarded merely as a terminological variant of the former. For Quine, the truth of this thesis was an open question. If true, some would argue that it undermines any belief in scientific theories that is based purely on their empirical success. But despite its potential (...) significance, surprisingly little has been done by way of establishing or refuting it. My aim is to establish the thesis for as large a class of theories as possible. Under various precisifications of the concepts involved, I show that it holds for all consistent and recursively axiomatizable theories that postulate infinitely many theoretical entities. (shrink)

Perhaps the most widely touted of GPT-4’s at-launch, zero-shot capabilities has been its reported 90th-percentile performance on the Uniform Bar Exam. This paper begins by investigating the methodological challenges in documenting and verifying the 90th-percentile claim, presenting four sets of findings that indicate that OpenAI’s estimates of GPT-4’s UBE percentile are overinflated. First, although GPT-4’s UBE score nears the 90th percentile when examining approximate conversions from February administrations of the Illinois Bar Exam, these estimates are heavily skewed towards repeat test-takers (...) who failed the July administration and score significantly lower than the general test-taking population. Second, data from a recent July administration of the same exam suggests GPT-4’s overall UBE percentile was below the 69th percentile, and $$\sim$$ ∼ 48th percentile on essays. Third, examining official NCBE data and using several conservative statistical assumptions, GPT-4’s performance against first-time test takers is estimated to be $$\sim$$ ∼ 62nd percentile, including $$\sim$$ ∼ 42nd percentile on essays. Fourth, when examining only those who passed the exam (i.e. licensed or license-pending attorneys), GPT-4’s performance is estimated to drop to $$\sim$$ ∼ 48th percentile overall, and $$\sim$$ ∼ 15th percentile on essays. In addition to investigating the validity of the percentile claim, the paper also investigates the validity of GPT-4’s reported scaled UBE score of 298. The paper successfully replicates the MBE score, but highlights several methodological issues in the grading of the MPT + MEE components of the exam, which call into question the validity of the reported essay score. Finally, the paper investigates the effect of different hyperparameter combinations on GPT-4’s MBE performance, finding no significant effect of adjusting temperature settings, and a significant effect of few-shot chain-of-thought prompting over basic zero-shot prompting. Taken together, these findings carry timely insights for the desirability and feasibility of outsourcing legally relevant tasks to AI models, as well as for the importance for AI developers to implement rigorous and transparent capabilities evaluations to help secure safe and trustworthy AI. (shrink)

This collection of 16 original articles by prominent theorists from a variety of disciplines provides an excellent insight into current thinking about artifacts. The four sections address issues concerning the metaphysics of artifacts, the nature and cognitive development of artifact concepts, and the place of artifacts in evolutionary history. The most overtly philosophical contributions are in the first two sections. Metaphysical issues addressed include the ‘mind-dependence’ of artifacts and the bearing of this on their ‘real’ existence, and the distinction between (...) natural and artifact kinds, and its implications for issues in epistemology and semantics – for example, whether there is ‘maker's knowledge’ of artifacts, and whether ‘direct’ theories of reference apply to artifact-kind terms. The papers concerned with the nature of artifact concepts – the ways in which we represent artifacts to ourselves – address how judgements of artifact identity track judgements about manifest appearance, function, and maker's intentions, and the neuroscientific basis for artifact categorization. Papers …. (shrink)

This two-part article offers a defense of a libertarian doctrine that centers on two propositions. The first is the self-ownership thesis according to which each individual possesses original moral rights over her own body, faculties, talents, and energies. The second is the anti-egalitarian conclusion that, through the exercise of these rights of self-ownership, individuals may readily become entitled to substantially unequal extra-personal holdings. The self-ownership thesis remains in the background during Part I of this essay, while the anti-egalitarian conclusion is (...) supported in two ways. First, I offer a reconstruction of Robert Nozick's well-known `How Liberty Upsets Patterns' argument against all end-state and pattern theories of distributive justice; and I defend this reconstructed stance against what might (otherwise) seem to be telling criticisms. Second, I defend the two key principles of Nozickian historical entitlement theory (the principle of just transfer and the principle of just initial acquisition) against criticisms offered by G.A. Cohen. Part II will center on Cohen's contention that the crucial basis for the anti-egalitarian conclusion is the self-ownership thesis. There I argue that Cohen is correct to hold that he must reject the self-ownership thesis if he is to avoid the anti-egalitarian conclusion; but he is wrong to think that he has an adequate basis for rejecting this thesis. Thus, both elements in the libertarianism under consideration are vindicated. And, the self-ownership thesis plays a surprisingly direct role in vindicating the anti-egalitarian conclusion. (shrink)

We show in this paper that some expressions indicating source of evidence are part of propositional content and are best analyzed as special kind of epistemic modal. Our evidence comes from the Japanese evidential system. We consider six evidentials in Japanese, showing that they can be embedded in conditionals and under modals and that their properties with respect to modal subordination are similar to those of ordinary modals. We show that these facts are difficult for existing theories of evidentials, which (...) assign evidentials necessarily widest scope, to explain. We then provide an analysis using a logical system designed to account for evidential reasoning; this logic is the first developed system of probabilistic dynamic predicate logic. This analysis is shown to account for the data we provide that is problematic for other theories. (shrink)

The cognitive science of belief is a burgeoning field, with insights ranging from detailing the fundamental structure of the mind, to explaining the spread of fake news. Here we highlight how new insights into belief acquisition, storage, and change can transform our understanding of psychiatric disorders. Although we focus on monothematic delusions, the conclusions apply more broadly. -/- .