The Humean argument concerning miracles says that one should always think it more likely that anyone who testifies to a miracle is lying or deluded than that the alleged miracle actually occurred, and so should always reject any single report of it. A longstanding and widely accepted objection is that even if this is right, the concurring and non-collusive testimony of many witnesses should make it rational to believe in whatever miracle they all report. I argue that on the contrary, (...) even multiple reports from non-collusive witnesses lack the sort of independence that could make trouble for Hume. (shrink)

The topic and methods of David Hume’s "Of Miracles" resemble his historiographical more than his philosophical works. Unfortunately, Hume and his critics and apologists have shared the prescientific, indeed ahistorical, limitations of Hume’s original historical investigations. I demonstrate the advantages of the critical methodological approach to testimonies, developed initially by German biblical critics in the late eighteenth century, to a priori discussions of miracles. Any future discussion of miracles and Hume must use the critical method to improve the quality and (...) relevance of the debate. (edited). (shrink)

This paper aims to clarify a debate on philosophical method, and to give a probabilistic argument vindicating armchair philosophy under a wide range of plausible assumptions. The use of intuitions by so-called armchair philosophers has been criticized on empirical grounds. The debate between armchair philosophers and their empirical critics would benefit from greater clarity and precision in our understanding of what it takes for intuition-based approaches to philosophy to make sense. This paper discusses a set of rigorous, probability-based tools for (...) determining what we can and cannot learn from intuitions in various conditions. These tools can tell us whether beliefs can be justified by armchair practices, and what empirical findings would have to show to undermine the use of intuitions in philosophy. Using these tools, the paper shows that armchair philosophy makes sense in a broad range of situations, and that it is quite plausible that we are in those situations at the moment. (shrink)

It is well known that probabilistic support is not transitive. But it can be shown that probabilistic support is transitive provided the intermediary proposition screens off the original evidence with respect to the hypothesis in question. This has the consequence that probabilistic support is transitive when the original evidence is testimonial, memorial or perceptual (i.e., to the effect that such and such was testified to, remembered, or perceived), and the intermediary proposition is its representational content (i.e., to the effect that (...) the such and such occurred). (shrink)

Probabilistic support is not transitive. There are cases in which x probabilistically supports y , i.e., Pr( y | x ) > Pr( y ), y , in turn, probabilistically supports z , and yet it is not the case that x probabilistically supports z . Tomoji Shogenji, though, establishes a condition for transitivity in probabilistic support, that is, a condition such that, for any x , y , and z , if Pr( y | x ) > Pr( y (...) ), Pr( z | y ) > Pr( z ), and the condition in question is satisfied, then Pr( z | x ) > Pr( z ). I argue for a second and weaker condition for transitivity in probabilistic support. This condition, or the principle involving it, makes it easier (than does the condition Shogenji provides) to establish claims of probabilistic support, and has the potential to play an important role in at least some areas of philosophy. (shrink)

Hume's essay on the credibility of miracle reports has always been controversial, with much debate over how it should be interpreted, let alone assessed. My aim here is to summarise what I take to be the most plausible views on these issues, both interpretative and philosophical, with references to facilitate deeper investigation if desired. The paper is divided into small sections, each headed by a question that provides a focus. Broadly speaking, §§1–3 and §20 are on Hume's general philosophical framework (...) within which the essay is situated, §§4–11 and §19 are on Part 1, §12–18 are on Part 2, and the final three sections §§18–20 sum up my assessment of his arguments. (shrink)

Testimonial evidence that is particularly helpful to confirmation combines agreement on some content with variation of detail. I examine the phenomenon of “undesigned coincidences” from a probabilistic point of view to explain how varied reports, including those that dovetail in detail, assist confirmation of an hypothesis. The formal analysis uses recent work in probability theory surrounding the concepts of dependence, independence, and varied evidence. I also discuss the connection between these types of report connections and an hypothesis about the reliability (...) of the sources involved. (shrink)

While it is natural to assume that contradiction between alleged witness testimonies to some event disconfirms the event, this generalization is subject to important qualifications. I consider a series of increasingly complex probabilistic cases that help us to understand the effect of contradictions more precisely. Due to the possibility of honest error on a difficult detail even on the part of highly reliable witnesses, agreement on such a detail can confirm H much more than contradiction disconfirms H. It is also (...) possible to model scenarios where we strongly suspect ahead of time that one source has copied another. In these cases, contradiction on a detail due to witness error can even confirm H by disconfirming collusion or copying. Finally, still more complex scenarios show that indirect confirmation, as opposed to exact agreement, provides the “best of both worlds,” simultaneously disconfirming suspected copying while permitting the statements of both sources to be true. (shrink)

A focus on the conjunction of the contents of witness reports and on the coherence of their contents has had negative effects on the epistemic clarity of the Bayesian coherence literature. Whether or not increased coherence of witness reports is correlated with higher confirmation for some H depends upon the hypothesis in question and upon factors concerning the confirmation and independence of the reports, not directly on the positive relevance of the contents to each other. I suggest that Bayesians should (...) shift focus to “coherence for” an hypothesis – that is, to the definition and analysis of cumulative case arguments in which a body of evidence supports some hypothesis that is not restricted to the conjunction of the contents of reports. Such a shift of focus will be valuable for approaching issues such as the problem of the external world which have interested Bayesian coherentists all along. (shrink)

In the debate over testimony to miracles, a common Humean move is to emphasize the prior improbability of miracles as the most important epistemic factor. Robert Fogelin uses the example of Henry, who tells multiple tall tales about meeting celebrities, to argue that low prior probabilities alone can render testimony unbelievable, with obvious implications for testimony to miracles. A detailed Bayesian analysis of Henry’s stories shows instead that the fact that Henry tells multiple stories about events that occurred independently if (...) they occurred at all is crucial to his loss of credibility. The epistemic structure is similar to that of a case of multiple lottery wins by the same person. Each of Henry’s stories can confirm only one event, but all the stories confirm the hypothesis that Henry is a liar. This structure does not apply to testimony to just one event, however antecedently improbable. Such examples therefore do nothing to undermine a standard Bayesian analysis involving both priors and likelihoods in evaluating testimony to an improbable event. (shrink)