•  14
    A new reading in Diogenes of Oinoanda fr. 69
    Classical Quarterly 49 (02): 639-. 1999.
    In fr. 69 Smith, the Epicurean Diogenes of Oinoanda, like Lucretius 4.353–63, explains why a square tower viewed from the distance appears to be round. The explanation is that εἲδωλα, filmy atomic images, emanating from the tower, are forced out of shape by the air through which they pass on their way to our eyes. Diogenes’ account is fragmentarily preserved on a stone which I discovered in 1970. The stone bears the right half of one fourteen-line column and the left half of a second one. I firs…Read more
  •  62
    Underdetermination and closure: Thoughts on two sceptical arguments
    In Matthew Jope & Duncan Pritchard (eds.), New Perspectives on Epistemic Closure, Routledge. forthcoming.
    In this paper, I offer reasons for thinking that two prominent sceptical arguments in the literature – the underdetermination-based sceptical argument and the closure-based sceptical argument – are less philosophically interesting than is commonly supposed. The underdetermination-based argument begs the question against a non-sceptic and can be dismissed with little fanfare. The closure-based argument, though perhaps not question-begging per se, does rest upon contentious assumptions that a no…Read more
  •  55
    Civil liability and the 50%+ standard of proof
    International Journal of Evidence and Proof 25 (3): 183-199. 2021.
    The standard of proof applied in civil trials is the preponderance of evidence, often said to be met when a proposition is shown to be more than 50% likely to be true. A number of theorists have argued that this 50%+ standard is too weak – there are circumstances in which a court should find that the defendant is not liable, even though the evidence presented makes it more than 50% likely that the plaintiff’s claim is true. In this paper, I will recapitulate the familiar arguments for this the…Read more
  •  160
    In this paper I respond to Marcello Di Bello’s criticisms of the ‘normic account’ of the criminal standard of proof. In so doing, I further elaborate on what the normic account predicts about certain significant legal categories of evidence, including DNA and fingerprint evidence and eyewitness identifications.
  •  306
    The Hardest Paradox for Closure
    Erkenntnis 1-26. forthcoming.
    According to the principle of Conjunction Closure, if one has justification for believing each of a set of propositions, one has justification for believing their conjunction. The lottery and preface paradoxes can both be seen as posing challenges for Closure, but leave open familiar strategies for preserving the principle. While this is all relatively well-trodden ground, a new Closure-challenging paradox has recently emerged, in two somewhat different forms, due to Marvin Backes (2019a) and …Read more
  •  882
    A Generalised Lottery Paradox for Infinite Probability Spaces
    British Journal for the Philosophy of Science 61 (4): 821-831. 2010.
    Many epistemologists have responded to the lottery paradox by proposing formal rules according to which high probability defeasibly warrants acceptance. Douven and Williamson present an ingenious argument purporting to show that such rules invariably trivialise, in that they reduce to the claim that a probability of 1 warrants acceptance. Douven and Williamson’s argument does, however, rest upon significant assumptions – amongst them a relatively strong structural assumption to the effect that t…Read more
  •  567
    Against legal probabilism
    In Jon Robson & Zachary Hoskins (eds.), The Social Epistemology of Legal Trials, Routledge. 2021.
    Is it right to convict a person of a crime on the basis of purely statistical evidence? Many who have considered this question agree that it is not, posing a direct challenge to legal probabilism – the claim that the criminal standard of proof should be understood in terms of a high probability threshold. Some defenders of legal probabilism have, however, held their ground: Schoeman (1987) argues that there are no clear epistemic or moral problems with convictions based on purely statistical e…Read more
  •  69
    Epistemic logic without closure
    Synthese 198 (5): 4751-4774. 2019.
    All standard epistemic logics legitimate something akin to the principle of closure, according to which knowledge is closed under competent deductive inference. And yet the principle of closure, particularly in its multiple premise guise, has a somewhat ambivalent status within epistemology. One might think that serious concerns about closure point us away from epistemic logic altogether—away from the very idea that the knowledge relation could be fruitfully treated as a kind of modal operator. …Read more
  •  1605
    What Else Justification Could Be1
    Noûs 44 (1): 10-31. 2010.
    According to a captivating picture, epistemic justification is essentially a matter of epistemic or evidential likelihood. While certain problems for this view are well known, it is motivated by a very natural thought—if justification can fall short of epistemic certainty, then what else could it possibly be? In this paper I shall develop an alternative way of thinking about epistemic justification. On this conception, the difference between justification and likelihood turns out to be akin to t…Read more
  •  1860
    Ceteris Paribus Conditionals and Comparative Normalcy
    Journal of Philosophical Logic 36 (1): 97-121. 2007.
    Our understanding of subjunctive conditionals has been greatly enhanced through the use of possible world semantics and, more precisely, by the idea that they involve variably strict quantification over possible worlds. I propose to extend this treatment to ceteris paribus conditionals – that is, conditionals that incorporate a ceteris paribus or ‘other things being equal’ clause. Although such conditionals are commonly invoked in scientific theorising, they traditionally arouse suspicion and ap…Read more
  •  218
    Varieties of Risk
    with Philip A. Ebert and Ian Durbach
    Philosophy and Phenomenological Research 101 (2): 432-455. 2020.
    The notion of risk plays a central role in economics, finance, health, psychology, law and elsewhere, and is prevalent in managing challenges and resources in day-to-day life. In recent work, Duncan Pritchard (2015, 2016) has argued against the orthodox probabilistic conception of risk on which the risk of a hypothetical scenario is determined by how probable it is, and in favour of a modal conception on which the risk of a hypothetical scenario is determined by how modally close it is. In this …Read more
  •  281
    A ‘lottery belief’ is a belief that a particular ticket has lost a large, fair lottery, based on nothing more than the odds against it winning. The lottery paradox brings out a tension between the idea that lottery beliefs are justified and the idea that that one can always justifiably believe the deductive consequences of things that one justifiably believes – what is sometimes called the principle of closure. Many philosophers have treated the lottery paradox as an argument against the secon…Read more
  •  85
    Lottery judgments: A philosophical and experimental study
    with Philip A. Ebert and Ian Durbach
    Philosophical Psychology 31 (1): 110-138. 2018.
    In this paper, we present the results of two surveys that investigate subjects’ judgments about what can be known or justifiably believed about lottery outcomes on the basis of statistical evidence, testimonial evidence, and “mixed” evidence, while considering possible anchoring and priming effects. We discuss these results in light of seven distinct hypotheses that capture various claims made by philosophers about lay people’s lottery judgments. We conclude by summarizing the main findings, poi…Read more
  •  45
    Coin trials
    Canadian Journal of Philosophy 48 (5): 726-741. 2018.
    According to the JUSTIFIED FAIR COINS principle, if I know that a coin is fair, and I lack justification for believing that it won’t be flipped, then I lack justification for believing that it won’t land tails. What this principle says, in effect, is that the only way to have justification for believing that a fair coin won’t land tails, is by having justification for believing that it won’t be flipped at all. Although this seems a plausible and innocuous principle, in a recent paper Dorr, Goodm…Read more
  •  1578
    When Does Evidence Suffice for Conviction?
    Mind 127 (508): 1193-1218. 2018.
    There is something puzzling about statistical evidence. One place this manifests is in the law, where courts are reluctant to base affirmative verdicts on evidence that is purely statistical, in spite of the fact that it is perfectly capable of meeting the standards of proof enshrined in legal doctrine. After surveying some proposed explanations for this, I shall outline a new approach – one that makes use of a notion of normalcy that is distinct from the idea of statistical frequency. The pu…Read more
  •  359
    The logic of epistemic justification
    Synthese 195 (9): 3857-3875. 2018.
    Theories of epistemic justification are commonly assessed by exploring their predictions about particular hypothetical cases – predictions as to whether justification is present or absent in this or that case. With a few exceptions, it is much less common for theories of epistemic justification to be assessed by exploring their predictions about logical principles. The exceptions are a handful of ‘closure’ principles, which have received a lot of attention, and which certain theories of justif…Read more
  •  1728
    The Epistemology of Religion
    Analysis 74 (1): 135-147. 2014.
    The epistemology of religion is the branch of epistemology concerned with the rationality, the justificatory status and the knowledge status of religious beliefs – most often the belief in the existence of an omnipotent, omniscient and loving God as conceived by the major monotheistic religions. While other sorts of religious beliefs – such as belief in an afterlife or in disembodied spirits or in the occurrence of miracles – have also been the focus of considerable attention from epistemologis…Read more
  •  2412
    This book explores a question central to philosophy--namely, what does it take for a belief to be justified or rational? According to a widespread view, whether one has justification for believing a proposition is determined by how probable that proposition is, given one's evidence. In this book this view is rejected and replaced with another: in order for one to have justification for believing a proposition, one's evidence must normically support it--roughly, one's evidence must make the falsi…Read more
  •  1589
    God and the external world
    Ratio 24 (1): 65-77. 2011.
    There are a number of apparent parallels between belief in God and belief in the existence of an external world beyond our experiences. Both beliefs would seem to condition one's overall view of reality and one's place within it – and yet it is difficult to see how either can be defended. Neither belief is likely to receive a purely a priori defence and any empirical evidence that one cites either in favour of the existence of God or the existence of the external world would seem to blatantly be…Read more
  •  481
    Scepticism by a Thousand Cuts
    International Journal for the Study of Skepticism 6 (1): 44-52. 2016.
    _ Source: _Page Count 9 Global sceptical arguments seek to undermine vast swathes of our putative knowledge by deploying hypotheses that posit massive deception or error. Local sceptical arguments seek to undermine just a small region of putative knowledge, using hypotheses that posit deception or error of a more mundane kind. Those epistemologists who have devised anti-sceptical strategies have tended to have global sceptical arguments firmly in their sights. I argue here that local sceptical a…Read more
  •  276
    Review of Quitting Certainties by Michael G. Titelbaum (review)
    Notre Dame Philosophical Reviews. 2013.
  •  134
    Why throwing 92 heads in a row is not surprising
    Philosophers' Imprint 17. 2017.
    Tom Stoppard’s “Rosencrantz and Guildenstern Are Dead” opens with a puzzling scene in which the title characters are betting on coin throws and observe a seemingly astonishing run of 92 heads in a row. Guildenstern grows uneasy and proposes a number of unsettling explanations for what is occurring. Then, in a sudden change of heart, he appears to suggest that there is nothing surprising about what they are witnessing, and nothing that needs any explanation. He says ‘…each individual coin spun …Read more
  •  118
    Two Notions of Epistemic Risk
    Erkenntnis 78 (5): 1069-1079. 2013.
    In ‘Single premise deduction and risk’ (2008) Maria Lasonen-Aarnio argues that there is a kind of epistemically threatening risk that can accumulate over the course of drawing single premise deductive inferences. As a result, we have a new reason for denying that knowledge is closed under single premise deduction—one that mirrors a familiar reason for denying that knowledge is closed under multiple premise deduction. This sentiment has more recently been echoed by others (see Schechter 2011). In…Read more
  •  545
    Entitlement and Evidence
    Australasian Journal of Philosophy 91 (4): 735-753. 2013.
    Entitlement is conceived as a kind of positive epistemic status, attaching to certain propositions, that involves no cognitive or intellectual accomplishment on the part of the beneficiary — a status that is in place by default. In this paper I will argue that the notion of entitlement — or something very like it — falls out of an idea that may at first blush seem rather disparate: that the evidential support relation can be understood as a kind of variably strict conditional (in the sense of Le…Read more
  •  880
    Given a few assumptions, the probability of a conjunction is raised, and the probability of its negation is lowered, by conditionalising upon one of the conjuncts. This simple result appears to bring Bayesian confirmation theory into tension with the prominent dogmatist view of perceptual justification – a tension often portrayed as a kind of ‘Bayesian objection’ to dogmatism. In a recent paper, David Jehle and Brian Weatherson observe that, while this crucial result holds within classical pro…Read more
  •  663
    Some Thoughts on the JK-Rule1
    Noûs 46 (4): 791-802. 2012.
    In ‘The normative role of knowledge’ (2012), Declan Smithies defends a ‘JK-rule’ for belief: One has justification to believe that P iff one has justification to believe that one is in a position to know that P. Similar claims have been defended by others (Huemer, 2007, Reynolds, forthcoming). In this paper, I shall argue that the JK-rule is false. The standard and familiar way of arguing against putative rules for belief or assertion is, of course, to describe putative counterexamples. My a…Read more
  •  1374
    The Cost of Treating Knowledge as a Mental State
    In A. Carter, E. Gordon & B. Jarvis (eds.), Knowledge First, Approaches to Epistemology and Mind, Oxford University Press. pp. 95-112. 2017.
    My concern in this paper is with the claim that knowledge is a mental state – a claim that Williamson places front and centre in Knowledge and Its Limits. While I am not by any means convinced that the claim is false, I do think it carries certain costs that have not been widely appreciated. One source of resistance to this claim derives from internalism about the mental – the view, roughly speaking, that one’s mental states are determined by one’s internal physical state. In order to know that …Read more
  •  488
    The _Principle of Indifference_ was once regarded as a linchpin of probabilistic reasoning, but has now fallen into disrepute as a result of the so-called _problem of multiple of partitions_. In ‘Evidential symmetry and mushy credence’ Roger White suggests that we have been too quick to jettison this principle and argues that the problem of multiple partitions rests on a mistake. In this paper I will criticise White’s attempt to revive POI. In so doing, I will argue that what underlies the probl…Read more