Simple idealized models seem to provide more understanding than opaque, complex, and hyper-realistic models. However, an increasing number of scientists are going in the opposite direction by utilizing opaque machine learning models to make predictions and draw inferences, suggesting that scientists are opting for models that have less potential for understanding. Are scientists trading understanding for some other epistemic or pragmatic good when they choose a machine learning model? Or are the assumptions behind why minimal models provide understanding misguided? In (...) this paper, using the case of deep neural networks, I argue that it is not the complexity or black box nature of a model that limits how much understanding the model provides. Instead, it is a lack of scientific and empirical evidence supporting the link that connects a model to the target phenomenon that primarily prohibits understanding. (shrink)

Belief polarization occurs when subjects who disagree about some matter of fact are exposed to a mixed body of evidence that bears on that dispute. While we might expect mutual exposure to common evidence to mitigate disagreement, since the evidence available to subjects comes to consist increasingly of items they have in common, this is not what happens. The subjects’ initial disagreement becomes more pronounced because each person increases confidence in her antecedent belief. Kelly aims to identify the mechanisms that (...) underlie this phenomenon and assess whether these processes undermine the justification of polarized beliefs. He concludes that given evidentialism, justification is not undermined by the polarizing mechanisms. I take on board Kelly’s description of the polarizing mechanisms, but challenge his conclusion. I argue that on plausible versions of evidentialism, the beliefs that result from these routes to polarization are not justified. (shrink)

There is considerable agreement among epistemologists that certain abilities are constitutive of understanding-why. These abilities include: constructing explanations, drawing conclusions, and answering questions. This agreement has led epistemologists to conclude that understanding is a kind of know-how. However, in this paper, I argue that the abilities constitutive of understanding are the same kind of cognitive abilities that we find in ordinary cases of knowledge-that and not the kind of practical abilities associated with know-how. I argue for this by disambiguating between (...) different senses of abilities that are too often lumped together. As a consequence, non-reductionists about understanding—those that claim that understanding-why is not reducible to knowledge-that—need to find another way to motivate the view. In the end, the fact that abilities are constitutive of understanding-why does not give us reason to conclude that understanding is a kind of know-how. (shrink)

The laws of nature have come a long way since the time of Newton: quantum mechanics and relativity have given us good reasons to take seriously the possibility of laws which may be non-local, atemporal, ‘all-at-once,’ retrocausal, or in some other way not well-suited to the standard dynamical time evolution paradigm. Laws of this kind can be accommodated within a Humean approach to lawhood, but many extant non-Humean approaches face significant challenges when we try to apply them to laws outside (...) the time evolution picture. Thus for proponents of non-Humean approaches to lawhood there is a clear need for a novel non-Humean account which is capable of accommodating these sorts of laws. In this paper we propose such an account, characterizing lawhood in terms of constraints, which are understood as a form of modal structure. We demonstrate that our proposed realist account can indeed accommodate a large variety of laws outside the time evolution paradigm, and describe some possible applications to important philosophical problems. (shrink)

Previous research reported that college students' symbolic addition and subtraction fluency improved after training with non-symbolic, approximate addition and subtraction. These findings were widely interpreted as strong support for the hypothesis that the Approximate Number System (ANS) plays a causal role in symbolic mathematics, and that this relation holds into adulthood. Here we report four experiments that fail to find evidence for this causal relation. Experiment 1 examined whether the approximate arithmetic training effect exists within a shorter training period than (...) originally reported (2 vs 6 days of training). Experiment 2 attempted to replicate and compare the approximate arithmetic training effect to a control training condition matched in working memory load. Experiments 3 and 4 replicated the original approximate arithmetic training experiments with a larger sample size. Across all four experiments (N = 318) approximate arithmetic training was no more effective at improving the arithmetic fluency of adults than training with control tasks. Results call into question any causal relationship between approximate, non-symbolic arithmetic and precise symbolic arithmetic. (shrink)

Relational quantum mechanics (RQM) is an interpretation of quantum mechanics based on the idea that quantum states do not describe an absolute property of a system but rather a relationship between systems. There have recently been some criticisms of RQM pertaining to issues around intersubjectivity. In this article, we show how RQM can address these criticisms by adding a new postulate which requires that all of the information possessed by a certain observer is stored in physical variables of that observer (...) and thus is accessible by measurement to other observers. This makes it possible for observers to reach intersubjective agreement about quantum events that have occurred in the past. We suggest a possible ontology for a version of RQM employing this postulate; this ontology upholds the principle that quantum states are always relational, but it also postulates a set of quantum events that are not strictly relational. We show that the new postulate helps address the preferred basis problem in RQM. (shrink)

Dementia patients in the moderate-late stage of the disease can, and often do, express different preferences than they did at the onset of their condition. The received view in the philosophical literature argues that advance directives which prioritize the patient’s preferences at onset ought to be given decisive moral weight in medical decision-making. Clinical practice, on the other hand, favors giving moral weight to the preferences expressed by dementia patients after onset. The purpose of this article is to show that (...) the received view in the philosophical literature is inadequate and is out of touch with real clinical practice. I argue that having dementia is a cognitive transformative experience and that preference changes which result from this are legitimate and ought to be given moral weight in medical decision-making. This argument ought to encourage us to reduce our confidence in the moral weight of advance directives for dementia patients. (shrink)

Many states offer generous provision of fertility treatment, but this article asks whether and how such state funding can be justified. I argue that, at most, there is limited justification for state funding of fertility treatment as one good among many that could enable citizens to pursue valuable life projects, but not one that should have the privileged access to funding it is currently given. I then consider and reject reasons one might think that fertility treatment has a special claim (...) to funding, over the other goods that might enable life projects. First, I deny that fertility treatment has a special claim to funding on the grounds that infertility is a disease or disability. Second, I argue that individuals do not have a right to assistance with the project of having a child of their own. Third, I deny that providing fertility treatment is a special case on the grounds that having children is good for society. However, there may be one exception: states have a reason to fund fertility treatment for same sex couples that does not apply to heterosexual couples. (shrink)

This essay explores how the distinctively anthropological concept of culture provides uniquely valuable insights into the workings of science in its cultural context. Recent efforts by anthropologists to dislodge the traditional notion of culture as a homogenous, stable whole have opened up a variety of ways of imagining culture that place power differentials, flux, and contradiction at its center. Including attention to a wide variety of social domains outside the laboratory, attending to the ways nonscientists actively engage with scientific knowledge, (...) and focusing on the complex interactions that flow both into and out of research laboratories are ways the activities of both scientists and nonscientists can be situated in the heterogeneous matrtx of culture. Three images—the citadel, the rhizome, and the string figure—allow us to picture the discontinuous ways science both permeates and is permeated by cultural life. (shrink)

Under what conditions does machine learning (ML) model opacity inhibit the possibility of explaining and understanding phenomena? In this article, I argue that nonepistemic values give shape to the ML opacity problem even if we keep researcher interests fixed. Treating ML models as an instance of doing model-based science to explain and understand phenomena reveals that there is (i) an external opacity problem, where the presence of inductive risk imposes higher standards on externally validating models, and (ii) an internal opacity (...) problem, where greater inductive risk demands a higher level of transparency regarding the inferences the model makes. (shrink)

I argue that ML models used in science function as highly idealized toy models. If we treat ML models as a type of highly idealized toy model, then we can deploy standard representational and epistemic strategies from the toy model literature to explain why ML models can still provide epistemic success despite their lack of similarity to their targets.

This article contributes to a growing conversation about the role of numbers in promoting gendered agendas in potentially contradictory ways. Drawing from interviews with gender advisors—the professionals tasked with mainstreaming gender in development projects—in an East African country, I begin from the paradox that gender advisors articulate a strong preference for qualitative data to best capture the lives of the women they aim to assist while voicing a need for quantitative metrics. I demonstrate that gender advisors come to imagine metrics (...) as expeditious bureaucratic tools able to inspire cooperation from otherwise reluctant coworkers. I argue that development organizations are gendered in ways—acutely seen in how advisors struggle, are sidelined, and attempt to advance their goals with numbers—that lead to the utility of valuing quantitative metrics over qualitative ones. I establish two theoretical contributions: Gendered organizations theory is essential to understanding the adoption and globalization of performance metrics, and in an age of evidence-based decision making, the utility of quantified data to garner resources is heightened, rewarding those who adopt quantified knowledge production. I coin the term “the paradox of quantified utility” to describe how these material advantages encourage even skeptics to value quantitative metrics. (shrink)

Medical ethics assumes a clear boundary between clinical research and clinical medicine: one produces knowledge for the benefit of future patients, while the other provides optimal care to individuals right now. It also assumes that the two cannot be integrated without sacrificing the needs of the current patient to those of future patients. But integration could allow us to provide better care to everyone, now and in the future.

Ontological separation plays a key role in Aristotle’s metaphysical project: substances alone are ontologically χωριστόν. The standard view identifies Aristotelian ontological separation with ontological independence, so that ontological separation is a non-symmetric relation. I argue that there is strong textual evidence that Aristotle employs an asymmetric notion of separation in the Metaphysics—one that involves the dependence of other entities on the independent entity. I argue that this notion allows Aristotle to prevent the proliferation of substance-kinds and thus to secure the (...) unity of his metaphysical system. (shrink)

The last decade has witnessed renewed attempts to regulate the conduct of transnational corporations. One way to do this is via global ethics codes. This paper examines seven such codes (the Sullivan Principles, UN Center for Transnational Corporations’ Draft Code, OECD Guidelines, ILO's Tripartite Declaration, the Caux Round Table Principles for Business, Global Compact, and the United Nations Norms) to determine their coverage of human rights and concludes that if these initiatives succeed, particularly the more recent codes, transnational corporations may (...) emerge as a major force in promoting human rights globally. (shrink)

In this article I criticize some traditional impartiality practices in Western philosophical ethics and argue in favor of Marilyn Friedman’s dialogical practice of eliminating bias. But, I argue, the dialogical approach depends on a more fundamental practice of equanimity. Drawing on the works of Tibetan Buddhist thinkers Patrul Rinpoche and Khenpo Ngawang Pelzang, I develop a Buddhist-feminist concept of equanimity and argue that, despite some differences with the Western impartiality practices, equanimity is an impartiality practice that is not only psychologically (...) feasible but also central to loving relationships. I conclude by suggesting ways that feminist dialogical practices for eliminating bias and meditative practices are mutually supportive. (shrink)

Any successful interpretation of quantum mechanics must explain how our empirical evidence allows us to come to know about quantum mechanics. In this article, we argue that this vital criterion is not met by the class of ‘orthodox interpretations,’ which includes QBism, neo-Copenhagen interpretations, and some versions of relational quantum mechanics. We demonstrate that intersubjectivity fails in radical ways in these approaches, and we explain why intersubjectivity matters for empirical confirmation. We take a detailed look at the way in which (...) belief-updating might work in the kind of universe postulated by an orthodox interpretation, and argue that observers in such a universe are unable to escape their own perspective in order to learn about the structure of the set of perspectives that is supposed to make up reality according to these interpretations. We also argue that in some versions of these interpretations it is not even possible to use one’s own relative frequencies for empirical confirmation. Ultimately we conclude that it cannot be rational to believe these sorts of interpretations unless they are supplemented with some observer-independent structure which underwrites intersubjective agreement in at least certain sorts of cases. (shrink)

It is widely conceded by liberals that institutions alone are insufficient to ensure that citizens behave in the ways required for a liberal state to flourish, be stable, or function at all. A popular solution proposes cultivating virtues in order to secure the desired behaviours of citizens, where institutions alone would not suffice. A range of virtues are proposed to fill a variety of purported gaps in the liberal political order. Some appeal to virtues in order to secure state stability; (...) Rawls, for instance, claims that ‘citizens must have a sense of justice and the political virtues that support political and social institutions’ in order to ensure an ‘enduring society’. For Galston, citizens must possess a range of virtues in order for the state to function, including the virtues of courage, independence, tolerance, willingness to engage in public discourse, and law-abidingness. (shrink)

There is little agreement about Aristotle’s philosophy of geometry, partly due to the textual evidence and partly part to disagreement over what constitutes a plausible view. I keep separate the questions ‘What is Aristotle’s philosophy of geometry?’ and ‘Is Aristotle right?’, and consider the textual evidence in the context of Greek geometrical practice, and show that, for Aristotle, plane geometry is about properties of certain sensible objects—specifically, dimensional continuity—and certain properties possessed by actual and potential compass-and-straightedge drawings qua quantitative and (...) continuous. For their part, the objects of stereometry are potential sensible three-dimensional figures qua quantitative and continuous. (shrink)

Disturbances to one's sense of self, the feeling that one has ‘lost a part of oneself’ or that one ‘no longer feels like oneself,’ are frequently recounted throughout the bereavement literature. Engaging Allan Køster's important contribution to this issue, this article reinforces his suggestion that, by rupturing the existential texture of self-familiarity, bereavement can result in experiences of estrangement that can be meaningfully understood according to the concept of self-alienation. Nevertheless, I suggest that whilst Køster's relational interpretation of alienation as (...) the withdrawal of heteronomy can be applied to the experience of world-collapse in bereavement, what sets bereavement apart from other limit situations is the fact that it involves an intersubjective relation between the living and the dead. In contrast to Køster, therefore, I suggest that the experience of self-alienation that is distinctive to bereavement results from the fact that the bereaved is exposed to, and co-opted by, the absolute alterity of death itself. (shrink)

In the Buddhist ethical traditions, equanimity along with love, compassion, and sympathetic joy form what are called the four boundless qualities, which are affective states one cultivates for moral and spiritual development. But there is a sense in which equanimity seems very unlike the three others: love, compassion, and sympathetic joy all imply an emotional investment in others, whereas equanimity seems to imply an absence of such investment. This observation has provoked debate as to how to properly understand the relationship (...) between equanimity and the other three qualities. In this paper, I propose that equanimity - like love, compassion, and sympathetic joy - is itself a virtue of good intimate relationships and not in conflict with such virtues. (shrink)

Deception sometimes results in nonconsensual sex. A recent body of literature diagnoses such violations as invalidating consent: the agreement is not morally transformative, which is why the sexual contact is a rights violation. We pursue a different explanation for the wrongs in question: there is valid consent, but it is not consent to the sex act that happened. Semantic conventions play a key role in distinguishing deceptions that result in nonconsensual sex (like stealth condom removal) from those that don’t (like (...) white lies). Our framework is also applicable to more controversial cases, like those implicated in so-called “gender fraud” complaints. (shrink)

Genetic testing can be used to determine if unexplained fractures in children could have resulted from a predisposition to bone fractures, e.g., osteogenesis imperfecta. However, uncertainty is introduced if a variant of unknown significance is identified. Proper interpretation of VUS in these situations is critical because of its influence on clinical care and in court rulings. This study sought to understand how VUS are interpreted and used by practitioners when there is a differential diagnosis including both osteogenesis imperfecta and non-accidental (...) injury.A 15-question survey was emailed to physicians who requested analysis of two genes, COL1A1 and COL1A2, from the University of Washington from 2005-2013 for patient cases involving suspicion of child abuse.Among the 89 participants, responses differed about when genetic testing should be ordered for osteogenesis imperfecta, who should be consulted about utilization of VUS test results, follow-up procedures, and who should receive the VUS results.There are no clear guidelines for how to interpret and follow up on VUS. In the legal setting, misinterpreted VUS could lead to unintended consequences and deleterious ramifications for family members. The need for better practice guidelines to help promote more equitable handling of these sensitive legal cases is clear. (shrink)

When a loved one dies, it is common for the bereaved to feel profoundly lonely, disconnected from the world with the sense that they no longer belong. In philosophy, this experience of ‘loss and loneliness’ has been interpreted according to both a loss of possibilities and a loss of the past. But it is unclear how these interpretations apply to the distinctive way in which loss and loneliness manifest in old age. Drawing on the phenomenological analyses of old age given (...) by de Beauvoir and Améry, I consider how the diminishment of the capacity for projection and recollection complicate recent interpretations of loss and loneliness, whilst nevertheless reinforcing the conclusion that in old age subjectivity is necessarily impoverished. Developing a critical stance on de Beauvoir and Améry’s underlying conception of subjectivity, I turn to Levinas in considering whether or not there is a way to reimagine subjectivity such that the estrangement and alienation of older adults might be ameliorated rather than exacerbated. Grounded in the passive body-in-itself rather than the self-transcending capacity of the body-for-itself, I suggest it becomes possible to reconceptualise the experience of loss and loneliness in old age; both in terms of what is lost and what needs to be restored if older adults are to be helped to find themselves at home in the world in the midst of, and indeed because of, manifold loss. (shrink)

Boredom is an affective experience that can involve pervasive feelings of meaninglessness, emptiness, restlessness, frustration, weariness and indifference, as well as the slowing down of time. An increasing focus of research in many disciplines, interest in boredom has been intensified by the recent Covid-19 pandemic, where social distancing measures have induced both a widespread loss of meaning and a significant disturbance of temporal experience. This article explores the philosophical significance of this aversive experience of ‘pandemic boredom.’ Using Heidegger’s work as (...) a unique vantage point, this article draws on survey data collected by researchers in an ongoing project titled ‘Experiences of Social Distancing During the Covid-19 Pandemic’ to give an original phenomenological interpretation of the meaninglessness and monotony of pandemic boredom. On a Heideggerian interpretation, pandemic boredom involves either a situative confrontation with relative meaninglessness that upholds our absorption in the everyday world, or an existential confrontation with absolute meaninglessness that forces us to take up the question of our existence. Arguing that boredom during the pandemic makes this distinction difficult to sustain, I consider some of the ways in which pandemic boredom might be seen to expose and then exceed the distinctive methodological limitations of Heidegger’s philosophical interpretation of boredom. (shrink)

Recently, many have argued that there are certain kinds of abstract mathematical explanations that are noncausal. In particular, the irrelevancy approach suggests that abstracting away irrelevant causal details can leave us with a noncausal explanation. In this paper, I argue that the common example of Renormalization Group explanations of universality used to motivate the irrelevancy approach deserves more critical attention. I argue that the reasons given by those who hold up RG as noncausal do not stand up to critical scrutiny. (...) As a result, the irrelevancy approach and the line between casual and noncausal explanation deserves more scrutiny. (shrink)

We agree with McCullough, Coverdale and Chervenak1 that ‘medical educators and academic leaders are in a pivotal and powerful position to role model’ to counter ‘incivility’ in medicine, which can include ‘dismissing’ or ‘demeaning others’. They note that ‘women may be at greater risk for experiencing incivility compared with men’, as may other individuals who experience ‘patterns of disrespect based on minority status’. The authors promote ‘professionalism’ and ‘etiquette’ to foster civility within medicine. Yet theory and experience suggest that medical (...) educators and academic leaders are also in powerful positions to mobilise these concepts to perpetuate exclusions from, and biases within, medicine, upholding racist, sexist and ableist norms. Feminist methodology reveals how ethical theorising historically excluded views and experiences of marginalised individuals and groups and provides frameworks for interrogating supposedly universal norms. Presuming dominant values and experiences reflect universal ones can further marginalise already oppressed groups and individuals. A feminist analysis reveals how ‘professionalism’ or ‘etiquette’ are historically shaped by white or male identity and experience, including norms of attire, hair, accessories, speech or behaviour. Part of the hidden curriculum of medicine becomes intuiting how leaders implicitly or explicitly define ‘professionalism’. McCullough et al define ‘professionalism’ in medicine as ‘sustained commitments to scientific and clinical excellence… making the protection and promotion of health-related interest the physician’s primary concern …. (shrink)

In this article we set out to understand the significance of the process matrix formalism and the quantum causal modelling programme for ongoing disputes about the role of causation in fundamental physics. We argue that the process matrix programme has correctly identified a notion of ‘causal order’ which plays an important role in fundamental physics, but this notion is weaker than the common-sense conception of causation because it does not involve asymmetry. We argue that causal order plays an important role (...) in grounding more familiar causal phenomena. Then we apply these conclusions to the causal modelling programme within quantum foundations, arguing that since no-signalling quantum correlations cannot exhibit causal order, they should not be analysed using classical causal models. This resolves an open question about how to interpret fine-tuning in classical causal models of no-signalling correlations. Finally we observe that a quantum generalization of causal modelling can play a similar functional role to standard causal reasoning, but we emphasize that this functional characterisation does not entail that quantum causal models offer novel explanations of quantum processes. (shrink)

In Buddhist contexts, avidyā refers not only to a lack of knowledge but also (and primarily) to an active misapprehension of reality, a warped projection onto reality that reinforces our own dysfunction and vice. Ignorance is rarely innocent; it is not an isolated phenomenon of just-not-happening-to-know-something. It is maintained and reinforced through personal and social habits, including practices of personal and collective false projection, strategic ignoring, and convenient “forgetting.” This view of avidyā has striking similarities to philosophical analyses of white (...) ignorance, such as Charles Mills’, which understand white ignorance not in terms of a passive lack of knowledge but as an active refusal by whites to confront basic facts about our social world (Mills 2007, 16). I argue that Buddhist analyses of avidyā may help us understand the mechanisms of white ignorance and the practices for deconstructing it. (shrink)

By clarifying the psychoanalytic notion of sexual difference, I argue that the symbolic dimension of psychical life cannot be discarded in developing political accounts of identity formation and the status of women in the public sphere. I discuss various bridges between social reality and symbolic structure, bridges such as body, language, law, and family. I conclude that feminist attention must be redirected to the unconscious since the political cannot be localized in, or segregated to, the sphere of social reality; sexual (...) difference is an indispensable concept for a feminist politics. (shrink)

Over the last several decades there has been an increase in the amount of research conducted concerning academically dishonest behaviors at the undergraduate level. However, this research and subsequent interventions are based on the assumptions that there exists a clear understanding of what constitutes academic dishonesty. In an attempt to address this gap in the current literature, a concept synthesis of students’ perceptions of academic behavior was completed. The end result was 18 categories of potentially dishonest academic behaviors. Definitions and (...) examples are explored. Inter-rater reliability was completed and Kappa values are reported as well as implications for teaching and future research. (shrink)

Given a rich environment, how do we decide on what information to use? A view of a single entity (e.g., a group of birds) affords many distinct interpretations, including their number, average size, and spatial extent. An enduring challenge for cognition, therefore, is to focus resources on the most relevant evidence for any particular decision. In the present study, subjects completed three tasks—number discrimination, surface area discrimination, and convex hull discrimination—with the same stimulus set, where these three features were orthogonalized. (...) Therefore, only the relevant feature provided consistent evidence for decisions in each task. This allowed us to determine how well humans discriminate each feature dimension and what evidence they relied on to do so. We introduce a novel computational approach that fits both feature precision and feature use. We found that the most relevant feature for each decision is extracted and relied on, with minor contributions from competing features. These results suggest that multiple feature dimensions are separately represented for each attended ensemble of many items and that cognition is efficient at selecting the appropriate evidence for a decision. (shrink)

This article examines the regulation of Latina youth sexualities in the context of sexual and reproductive health care provision. In-depth interviews with health care providers working in two Latino-serving community health centers are analyzed for how they interpret and respond to the sexual and reproductive practices of their low-income Latina teen patients. The author finds that providers emphasize teenage pregnancy as a social problem among this population to the exclusion of other dimensions of youth sexualities and encourage Latina girls’ adherence (...) to a life course trajectory that conforms to middle-class, heteronormative ideals as a solution to this problem. By relying on such understandings, providers construct meanings of sexual citizenship that require participation in bourgeois heteronormativity. These findings suggest that Latino-serving community health centers, their providers, and their teen patients could benefit from questioning the assumptions that inform providers’ appraisals of Latina youth and developing a more inclusive approach to Latina youth sexualities beyond a discourse of pregnancy prevention. Such efforts could allow community health centers to actively participate in disrupting the structural inequalities that shape their young patients’ lives. (shrink)

I argue that the Oxford school Everett interpretation is internally incoherent, because we cannot claim that in an Everettian universe the kinds of reasoning we have used to arrive at our beliefs about quantum mechanics would lead us to form true beliefs. I show that in an Everettian context, the experimental evidence that we have available could not provide empirical confirmation for quantum mechanics, and moreover that we would not even be able to establish reference to the theoretical entities of (...) quantum mechanics. I then consider a range of existing Everettian approaches to the probability problem and show that they do not succeed in overcoming this incoherence. (shrink)

A vibrant history of acoustical technology and aural culture in early-twentieth-century America.

In this paper, we explain and showcase the promising methodology of testimonial network analysis and visualization for experimental epistemology, arguing that it can be used to gain insights and answer philosophical questions in social epistemology. Our use case is the epistemic community that discusses vaccine safety primarily in English on Twitter. In two studies, we show, using both statistical analysis and exploratory data visualization, that there is almost no neutral or ambivalent discussion of vaccine safety on Twitter. Roughly half the (...) accounts engaging with this topic are pro-vaccine, while the other half are con-vaccine. We also show that these two camps rarely engage with one another, and that the con-vaccine camp has greater epistemic reach and receptivity than the pro-vaccine camp. In light of these findings, we question whether testimonial networks as they are currently constituted on popular fora such as Twitter are living up to their promise of delivering the wisdom of crowds. We conclude by pointing to directions for further research in digital social epistemology. (shrink)