The past 15 years occasioned an extraordinary blossoming of research into the cognitive and affective mechanisms that support moral judgment and behavior. This growth in our understanding of moral mechanisms overshadowed a crucial and complementary question, however: How are they learned? As this special issue of the journal Cognition attests, a new crop of research into moral learning has now firmly taken root. This new literature draws on recent advances in formal methods developed in other domains, such as Bayesian inference, (...) reinforcement learning and other machine learning techniques. Meanwhile, it also demonstrates how learning and deciding in a social domain—and especially in the moral domain—sometimes involves specialized cognitive systems. We review the contributions to this special issue and situate them within the broader contemporary literature. Our review focuses on how we learn moral values and moral rules, how we learn about personal moral character and relationships, and the philosophical implications of these emerging models. (shrink)

Social change is slow and difficult. Social change for animals is formidably slow and difficult. Advocates and scholars alike have long tried to change attitudes and convince the public that eating animals is wrong. The topic of norms and social change for animals has been neglected, which explains in part the relative failure of the animal protection movement to secure robust support reflected in social and legal norms. Moreover, animal ethics has suffered from a disproportionate focus on individual attitudes and (...) behavior at the expense of collective behavior, social change, and empirical psychology. If what we want to change is behavior on a large scale, norms are important tools. This article reviews an account of social norms that provides insights into the possibility and limitations of social change for animals, approaching animal protection as a problem of reverse social engineering. It highlights avenues for future work from this neglected perspective. (shrink)

Consider how we evaluate how normal an object is. On the dual-nature hypothesis, a normality evaluation depends on the object’s goodness and frequency. On the single-nature hypothesis, the evaluation depends solely on either frequency or goodness. To assess these hypotheses, I ran four experiments. Study 1 shows that normality evaluations vary with both the goodness and the frequency assessment of the object. Study 2 shows that manipulating the goodness and the frequency dimension changes the normality evaluation. Yet, neither experiment rules (...) out that some people evaluate normality solely based on frequency, and the rest evaluate normality solely based on goodness. Whence two more experiments. Study 3 reveals that when scenarios are contrasted—presented one after another—only frequency matters. But, as study 4 shows, when scenarios are evaluated alone, both frequency and goodness influence normality evaluations in a single person, although the more a person is sensitive to one dimension, the less she’s sensitive to the other. The dual-nature hypothesis seems thus true of uncontrasted applications of the concept of normality, whereas the single-nature hypothesis seems true of contrasted applications. (shrink)

Incorporating normality ascriptions into counterfactual theories of causation was supposed to handle isomorphs. It doesn’t—conjoining isomorphs can produce cases that such ascriptions cannot resolve.

It has recently been argued that normative considerations play an important role in causal cognition. For instance, when an agent violates a moral rule and thereby produces a negative outcome, she will be judged to be much more of a cause of the outcome, compared to someone who performed the same action but did not violate a norm. While there is a substantial amount of evidence reporting these effects, it is still a matter of debate how this evidence is to (...) be interpreted. In this paper, we engage with the three most influential classes of explanations, namely, (a) the Norm‐Sensitive Cognitive Process View, (b) the Normative Concept View, and (c) the Pragmatics View. We will outline how these theories explain the empirical results and in what ways they differ. We conclude with a reflection on how well these strategies do overall and what questions they still leave unanswered. (shrink)

Acts that are considered undesirable standardly violate our expectations. In contrast, acts that count as morally desirable can either meet our expectations or exceed them. The zone in which an act can be morally desirable yet not exceed our expectations is what we call the zone of moral indifference, and it has so far been neglected. In this paper, we show that people can use positive terms in a deflated manner to refer to actions in the zone of moral indifference, (...) whereas negative terms cannot be so interpreted. (shrink)

We present an investigation of the ways in which speakers' subjective perspectives are likely to affect the meaning of gradable adjectives like tall or heavy. We present the results of a study showing that people tend to use themselves as a yardstick when ascribing these adjectives to human figures of varied measurements: subjects' height and weight requirements for applying tall and heavy are found to be positively correlated with their personal measurements. We draw more general lessons regarding the definition of (...) subjectivity and the ways in which a standard of comparison and a significant deviation from that standard are specified. (shrink)

How do people perceive the minds of organizations? Existing work on organizational mind perception highlights two key debates: whether organizational groups are ascribed more agency than experience, and whether people are really perceiving minds in organizational groups at all. Our current paper and its data weigh in on these debates and suggest that organizations can indeed be ascribed experiential minds. We present a “member and goals” framework for systematically understanding the mind perception of organization. This framework suggests that people can (...) perceive the organizational mind through its elemental building blocks: members (people who form the organization) and goals (its aims). Four studies reveal that people ascribe agency and experience to organizations based on whether the members of organizations and the goals of the organization are characterized by agency or experience. Study 1 finds that past work on mind perception often examines for‐profit corporations, which consist of agentic members (corporate professionals) and agentic goals (market competition). Studies 2 and 3 reveal that when an organization with members and goals high (vs. low) in experience, people imbue its mind with perceived experience—equal to that of a person—and that even emotions low in warmth (i.e., anger) can imbue an organization with such perceptions. Study 4 shows the moral consequences of emphasizing experience: after organizational wrongdoing, experiential organizations are seen to deliver more sincere apologies and are more forgiven. (shrink)

The term “normal” is culturally ubiquitous and conceptually vague. Interestingly, it appears to be a descriptive-normative-hybrid which, unnoticedly, bridges the gap between the descriptive and the normative. People’s beliefs about normality are descriptive and prescriptive and depend on both an average and an ideal. Besides, the term has generally garnered popularity in medicine. However, if medicine heavily relies on the normal, then it should point out how it relates to the concept of health or to statistics, and what, after all, (...) normal means. Most importantly, the normativity of the normal needs to be addressed. Since the apparently neutral label “normal” can exclude, stigmatize, and marginalize people who are defined in contrast to it as abnormal, health professionals should think twice before using the term with patients. The present critical perspective advocates against using the term “normal,” as long as no understanding of a person’s individual normality has been attained. It advocates for the right to autonomously determine one’s own normality. For health professionals I do not see worthwhile benefits of subscribing to the concept of “normality” and imposing it on their patients. But I do see many risks. (shrink)

Cognitive scientists have been debating how the folk concept of intentional action works. We suggest a simple account: people consider that an agent did X intentionally to the extent that X was causally dependent on how much the agent wanted X to happen (or not to happen). Combined with recent models of human causal cognition, this definition provides a good account of the way people use the concept of intentional action, and offers natural explanations for puzzling phenomena such as the (...) side-effect effect. We provide empirical support for our theory, in studies where we show that people’s causation and intentionality judgments track each other closely, in everyday situations as well as in scenarios with unusual causal structures. Study 5 additionally shows that the effect of norm violations on intentionality judgments depends on the causal structure of the situation, in a way uniquely predicted by our theory. Taken together, these results suggest that the folk concept of intentional action has been difficult to define because it is made of cognitive building blocks, such as our intuitive concept of causation, whose logic cognitive scientists are just starting to understand. (shrink)

How do scientific explanations for beliefs affect people's confidence that those beliefs are true? For example, do people think neuroscience-based explanations for belief in God support or challenge God's existence? In five experiments, we find that people tend to think explanations for beliefs corroborate those beliefs if the explanations invoke normally-functioning mechanisms, but not if they invoke abnormal functioning (where “normality” is a matter of proper functioning). This emerges across a variety of kinds of scientific explanations and beliefs (religious, moral, (...) and scientific). We also find evidence that these effects can interact with people's prior beliefs to produce motivated judgments. (shrink)

The application of artificial intelligence (AI) in hospitals yields many advantages but also confronts healthcare with ethical questions and challenges. While various disciplines have conducted specific research on the ethical considerations of AI in hospitals, the literature still requires a holistic overview. By conducting a systematic discourse approach highlighted by expert interviews with healthcare specialists, we identified the status quo of interdisciplinary research in academia on ethical considerations and dimensions of AI in hospitals. We found 15 fundamental manuscripts by constructing (...) a citation network for the ethical discourse, and we extracted actionable principles and their relationships. We provide an agenda to guide academia, framed under the principles of biomedical ethics. We provide an understanding of the current ethical discourse of AI in clinical environments, identify where further research is pressingly needed, and discuss additional research questions that should be addressed. We also guide practitioners to acknowledge AI-related benefits in hospitals and to understand the related ethical concerns. (shrink)

There is little debate regarding the acceptability of providing medical care to restore physical or mental health that has deteriorated below what is considered typical due to disease or disorder (i.e., providing “treatment”—for example, administering psychostimulant medication to sustain attention in the case of attention deficit disorder). When asked whether a healthy individual may undergo the same intervention for the purpose of enhancing their capacities (i.e., “enhancement”—for example, use of a psychostimulant as a “study drug”), people often express greater hesitation. (...) Building on prior research in moral philosophy and cognitive science, in this work, we ask why people draw a moral distinction between treatment and enhancement. In two experiments, we provide evidence that the accessibility of health-related interventions determines their perceived descriptive or statistical normality (Experiment 1), and that gains in descriptive normality for such interventions weaken the moral distinction between treatment and enhancement (Experiment 2). In short, our findings suggest that the tendency to draw a moral distinction between treatment and enhancement is driven, in part, by assumptions about descriptive abnormality; and raise the possibility that normalizing novel biomedical interventions by promoting access could undermine people’s selective opposition toward enhancement, rendering it morally comparable to treatment. (shrink)

A variety of recent work in epistemology employs a notion of normality to provide novel theories of knowledge or justification. While such theories are commonly advertised as affording particularly strong epistemic logics, they often make substantive assumptions about the background notion of normality and its logic. This article takes recent normality-based defences of the KK principle as a case study to submit such assumptions to scrutiny. After clarifying issues regarding the natural language use of normality claims, the article isolates a (...) number of choice points regarding the role of contingency, context-sensitivity and similarity in our theorizing with normality. It turns out that both weaker and stronger logics of normality can be motivated depending on how such choices are resolved. And yet securing logics of normality strong enough for normality to play its envisaged role in epistemology may have unwelcome downstream consequences for the resultant theories of knowledge or justification. (shrink)

This paper reports the first study in the literature that adopts a bibliometric approach to systematically explore the scholarship in the young and fast‐growing research field of experimental philosophy. Based on a corpus of 1,248 publications in experimental philosophy from the past two decades retrieved from the PhilPapers website, the study examined the publication trend, the influential experimental philosophers, the impactful works, the popular publication venues, and the major research themes in this subarea of philosophy. It found, first, an overall (...) growing trend in publications in experimental philosophy, encompassing four developmental stages. Second, it found that significant changes in topics of interest have taken place, with some gaining increasing attention, others seemingly going out of fashion, and still others remaining popular constantly. Third, the study identified lists of leading philosophers, frequently cited publications, and popular journals helpful for researchers and newcomers to get a quick start in learning about the field. (shrink)

Norm theory (Kahneman & Miller, 1986) described a tendency for people to associate stronger regret with a negative outcome when it is a result of an exception (abnormal behavior) compared to when it is a result of routine (normal behavior). In two pre-registered studies, we conducted a replication and extension of three classic experiments on past behavior exception/routine contrasts (N = 684). We successfully replicated Kahneman and Miller’s (1986) experiments with the classic hitchhiker-scenario (Part 1) and car accident-scenario (Part 2). (...) In both cases, participants examined negative outcomes and tended to indicate a protagonist who deviated from own past behavior as more regretful than another who followed routine. Pre-registered extensions also showed effects for ratings of social norms, negative affect, and perceived luck. We did not find support for the Miller and McFarland (1986) experiment robbery scenario (Part 3) using a compensation measure, in that compensation to a victim of a robbery was not significantly different comparing exceptional and routine circumstances. However, a pre-registered extension showed that robbery under exceptional circumstances was regretted more than robbery under routine circumstances. We discuss implications for current and future research. (shrink)

Moralization is a social-psychological process through which morally neutral issues take on moral significance. Often linked to health and disease, moralization may sometimes lead to good outcomes; yet moralization is often detrimental to individuals and to society as a whole. It is therefore important to be able to identify when moralization is inappropriate. In this paper, we offer a systematic normative approach to the evaluation of moralization. We introduce and develop the concept of ‘mismoralization’, which is when moralization is metaethically (...) unjustified. In order to identify mismoralization, we argue that one must engage in metaethical analysis of moralization processes while paying close attention to the relevant facts. We briefly discuss one historical example and two contemporary cases related to COVID-19 that we contend to have been mismoralized in public health. We propose a remedy of de-moralization that begins by identifying mismoralization and that proceeds by neutralizing inapt moral content. De-moralization calls for epistemic and moral humility. It should lead us to pull away from our tendency to moralize—as individuals and as social groups—whenever and wherever moralization is unjustified. (shrink)

Midwest Studies In Philosophy, EarlyView.

People often think of objects teleologically. For instance, we might understand a hammer in terms of its purpose of driving in nails. But how should we understand teleological thinking in the first place? This paper separates mere teleology (simply ascribing a telos) and teleological explanation (thinking something is explained by its telos) by examining cases where an object was designed for one purpose but is now widely used for a different purpose. Across four experiments, we show that teleology judgments and (...) teleological explanation judgments are dissociable, and identify three factors that influenced teleology judgments (and one that did not). (shrink)

Existing research suggests that people's judgments of actual causation can be influenced by the degree to which they regard certain events as normal. We develop an explanation for this phenomenon that draws on standard tools from the literature on graphical causal models and, in particular, on the idea of probabilistic sampling. Using these tools, we propose a new measure of actual causal strength. This measure accurately captures three effects of normality on causal judgment that have been observed in existing studies. (...) More importantly, the measure predicts a new effect ("abnormal deflation"). Two studies show that people's judgments do, in fact, show this new effect. Taken together, the patterns of people's causal judgments thereby provide support for the proposed explanation. (shrink)

In this paper, we propose a general constraint on theories of knowledge that we call ‘normalism’. Normalism is a view about the epistemic threshold that separates knowledge from mere true belief; its basic claim is that one knows only if one has at least a normal amount of epistemic support for one’s belief. We argue that something like normalism is required to do full justice to the normative role of knowledge in many key everyday practices, such as assertion, inquiry, and (...) testimony. The view of normality we employ to flesh out this claim is inspired by experimental work on the folk notion of normality, which suggests that folk judgments of what is ‘normal’ are based upon both statistical averages as well as normative ideals within the relevant target domain. Adopting this notion of normality to set the threshold for knowledge results in a view upon which knowledge is routinely available on an everyday basis without being a merely trivial achievement. We explore several interesting consequences of this view, including the implication that the threshold for knowing may change as, e.g., the ease of availability of information in an epistemic community changes over time. The result is a ‘shifty’ view of knowledge which nonetheless retains more stability than standard contextualist or pragmatic encroachment approaches. (shrink)

People more frequently select norm-violating factors, relative to norm- conforming ones, as the cause of some outcome. Until recently, this abnormal-selection effect has been studied using retrospective vignette-based paradigms. We use a novel set of video stimuli to investigate this effect for prospective causal judgments—i.e., judgments about the cause of some future outcome. Four experiments show that people more frequently select norm- violating factors, relative to norm-conforming ones, as the cause of some future outcome. We show that the abnormal-selection effects (...) are not primarily explained by the perception of agency (Experiment 4). We discuss these results in relation to recent efforts to model causal judgment. (shrink)

This paper explores the idea that vague predicates like “tall”, “loud” or “expensive” are applied based on a process of analog magnitude representation, whereby magnitudes are represented with noise. I present a probabilistic account of vague judgment, inspired by early remarks from E. Borel on vagueness, and use it to model judgments about borderline cases. The model involves two main components: probabilistic magnitude representation on the one hand, and a notion of subjective criterion. The framework is used to represent judgments (...) of the form “x is clearly tall” versus “x is tall”, as involving a shift of one’s criterion, and then to derive observed patterns of acceptance for borderline contradictions, namely sentences of the form “x is tall and not tall”, relative to the acceptance of their conjuncts. (shrink)

Existing research has shown that norm violations influence causal judgments, and a number of different models have been developed to explain these effects. One such model, the necessity/sufficiency model, predicts an interac- tion pattern in people’s judgments. Specifically, it predicts that when people are judging the degree to which a particular factor is a cause, there should be an interaction between (a) the degree to which that factor violates a norm and (b) the degree to which another factor in the (...) situation violates norms. A study of moral norms (N = 1000) and norms of proper functioning (N = 3000) revealed robust evidence for the predicted interaction effect. The implications of these patterns for existing theories of causal judgments is discussed. (shrink)

Over the past several decades, psychological essentialism has been an important topic of study, incorporating research from multiple areas of psychology, philosophy and linguistics. At its most basic level, essentialism is the tendency to represent certain concepts in terms of a deeper, unobservable property that is responsible for category membership. Originally, this concept was used to understand people’s reasoning about natural kind concepts, such as TIGER and WATER, but more recently, researchers have identified the emergence of essentialist-like intuitions in a (...) number of other contexts, including people’s representation of concepts like SCIENTIST or CHRISTIAN. This paper develops an account that aims to capture how essentialism may operate across these varied cases. In short, we argue that while there is diversity in the forms essentialism can take, these varied cases reflect the same underlying cognitive structure. (shrink)

BackgroundNormality is both a descriptive and a normative concept. Undoubtedly, the normal often operates normatively as an exclusionary tool of cultural authority. While it has prominently found its way into the field of medicine, it remains rather unclear in what sense it is used. Thus, our study sought to elucidate people’s understanding of normality in medicine and to identify concepts that are linked to it.MethodsUsing convenient sampling, we carried out a cross-sectional survey. Since the survey was advertised through social media, (...) we employed an online survey. We performed descriptive and inferential analyses. Predictors were chosen in a theory-driven manner.ResultsIn total, 323 persons from 21 countries completed the survey. Analysis revealed that the overall acceptance of normality in medicine was associated with notions of injustice, authority, discrimination, and with having a medical profession. More precisely, for the field of mental health, injustice insensitivity, genderism and transphobia, and authority were positively associated with a person’s acceptance of normality; and, for the field of physical health, injustice insensitivity and having a medical profession were positively associated with a person’s acceptance of normality. Finally, participants’ acceptance of the use of normality in the area of mental health was lower than in the area of physical health.ConclusionsWhat is considered normal has implications for clinical practice, both at an individual and at a policy-level. Acknowledging its normalistic condition, the discipline of medicine has to confront itself with its own contribution to the augmentation of social inequalities through the excessive reliance on the concept of normality. Research that centers the lived experiences of those who are being systematically marginalized because they are deemed abnormal is needed. By empirically elucidating the conceptual relationships between normality in medicine and other variables, we provide points of leverage to deprive normality of its normative power. For medicine, this is needed to first do no harm. (shrink)

People frequently entertain counterfactual thoughts, or mental simulations about alternative ways the world could have been. But the perceived plausibility of those counterfactual thoughts varies widely. The current article interfaces research in the philosophy and semantics of counterfactual statements with the psychology of mental simulations, and it explores the role of perceived similarity in judgments of counterfactual plausibility. We report results from seven studies (N = 6405) jointly supporting three interconnected claims. First, the perceived plausibility of a counterfactual event is (...) predicted by the perceived similarity between the possible world in which the imagined situation is thought to occur and the actual world. Second, when people attend to differences between imagined possible worlds and the actual world, they think of the imagined possible worlds as less similar to the actual world and tend to judge counterfactuals in such worlds as less plausible. Lastly, when people attend to what is identical between imagined possible worlds and the actual world, they think of the imagined possible worlds as more similar to the actual world and tend to judge counterfactuals in such worlds as more plausible. We discuss these results in light of philosophical, semantic, and psychological theories of counterfactual thinking. (shrink)

There is a widespread and largely unchallenged assumption within philosophy that the word ‘normal’ is ambiguous: i.e., that it can mean different things in different contexts. This assumption appears in work within topics as varied as the philosophy of biology, medicine, justification, causation, and more. In this paper I argue that we currently lack any independent reason for adopting such an assumption. The reason that would most likely be offered in its favour requires us to ignore an alternative and equally (...) plausible explanation for the seeming variety of different meanings that ‘normal’ is taken to have. Meanwhile, the well-known conjunction reduction test for ambiguity provides no evidence for the ambiguity of ‘normal’, and in fact suggests that maintaining this ambiguity claim is more difficult than has been initially supposed. Therefore, with the way things stand at present, it should not be assumed without argument that ‘normal’ is an ambiguous term. (shrink)

When solving problems, like making predictions or choices, people often “sample” possibilities into mind. Here, we consider whether there is structure to the kinds of thoughts people sample by default—that is, without an explicit goal. Across three experiments we found that what comes to mind by default are samples from a probability distribution that combines what people think is likely and what they think is good. Experiment 1 found that the first quantities that come to mind for everyday behaviors and (...) events are quantities that combine what is average and ideal. Experiment 2 found, in a manipulated context, that the distribution of numbers that come to mind resemble the mathematical product of the presented statistical distribution and a (softmax-transformed) prescriptive distribution. Experiment 3 replicated these findings in a visual domain. These results provide insight into the process generating people’s conscious thoughts and invite new questions about the value of thinking about things that are both likely and good. (shrink)

The past eighteen years witnessed the rapid development of experimental philosophy of language. Adopting a bibliometric approach, this study examines the research trends and status quo of this burgeoning field based on a corpus of 237 publications retrieved from PhilPapers. It is observed that experimental philosophy of language has undergone three stages, the initiation stage, the development stage, and the extension stage, across which there is a clear upward trend in the annual number of publications. Michael Devitt, Edouard Machery, John (...) Turri, Nat Hansen, et al., are found to be the most productive philosophers, testifying their leading positions in this field. Journals, instead of books, are the major homes of works in this area. The analysis also yields a list of influential works, including the seminal work “Semantics, Cross-cultural Style” and other significant publications on the semantics of various types of expressions. Relatedly, the major research themes are found to include not only intuitions about the reference of proper names, but also a wide array of philosophically and linguistically interesting issues like the meaning of color adjectives, epistemic modals, and predicates of personal taste, the norms of assertions and the essence of lies, etc. These findings showcase that experimental philosophy of language has broadened the research territory and offered deep insights into central issues of philosophy of language that are beyond the reach of the conventional armchair methodology. (shrink)

The reasonable person standard is key to both Criminal Law and Torts. What does and does not count as reasonable behavior and decision-making is frequently deter- mined by lay jurors. Hence, laypeople’s understanding of the term must be considered, especially whether they use it predominately in an evaluative fashion. In this corpus study based on supervised machine learning models, we investigate whether laypeople use the expression ‘reasonable’ mainly as a descriptive, an evaluative, or merely a value-associated term. We find that (...) ‘reasonable’ is predicted to be an evaluative term in the majority of cases. This supports prescriptive accounts, and challenges descriptive and hybrid accounts of the term—at least given the way we operationalize the latter. Interestingly, other expressions often used interchangeably in jury instructions (e.g. ‘careful,’ ‘ordinary,’ ‘prudent,’ etc), however, are predicted to be descriptive. This indicates a discrepancy between the intended use of the term ‘reasonable’ and the understanding lay jurors might bring into the court room. (shrink)

Coordinating competing interests can be difficult. Because law regulates human behavior, it is a candidate mechanism for creating coordination in the face of societal disagreement. We argue that findings from moral psy- chology are necessary to understand why law can effectively resolve co- occurring conflicts related to punishment and group membership. First, we discuss heterogeneity in punitive thought, focusing on punishment within the United States legal system. Though the law exerts a weak influence on punitive ideologies before punishment occurs, we (...) argue that it effectively coordinates perceptions of individuals who have already been punished. Next, we discuss intergroup conflict, which often co-occurs with disagree- ments related to punishment and represents a related domain where coor- dination can be difficult to achieve. Here, we underscore how insights from moral psychology can promote equality via the law. These examples demonstrate how contributions from moral psychology are necessary to understand the connection between social cognition and law. (shrink)

In this dissertation I develop a pluralist theory of actual causation. I argue that we need to distinguish between total, path-changing, and contributing actual causation. The pluralist theory accounts for a set of example cases that have raised problems for extant unified theories and it is supported by considerations about the various functions of causal concepts. The dissertation also analyses the context-sensitivity of actual causation. I show that principled accounts of causal reasoning in legal inquiry face limitations and I argue (...) that the context-sensitivity of actual causation is best represented by a distinction between default and deviant states in causal models. (shrink)

Within contemporary science, it is common practice to compare data points to the _average_, i.e., to the statistical mean. Because this practice is so familiar, it might at first appear not to be the sort of thing that requires explanation. But recent research in cognitive science gives us reason to adopt the opposite perspective. Research on the cognitive processes involved in people’s ordinary efforts to make sense of the world suggests that, instead of using a purely statistical notion of the (...) average, people tend to use a value-laden notion of the _normal_. This finding about ordinary cognition gives us reason to rethink certain familiar facts about scientific practice. In particular, it suggests that the fact that scientists so often make use of the statistical average should be seen as a highly surprising fact, the sort of thing that calls out for explanation. To understand it, we turn to work in the history of science, and especially to work on the ways in which the practice of science changed over the course of the 19th century. (shrink)