The recently offered, Purported counter-Examples to justified, True belief analyses of knowledge are looked at with some care and all found to be either incoherent or inconclusive. It is argued that justified, True belief analyses are based on sound insight into the concept of knowledge. The distinction between having been justified in claiming to know something and actually having known it is used in an effort to get the discussion of knowledge back on the right track.

In his influential book, The Nature of Morality, Gilbert Harman writes: “In explaining the observations that support a physical theory, scientists typically appeal to mathematical principles. On the other hand, one never seems to need to appeal in this way to moral principles.” What is the epistemological relevance of this contrast, if genuine? This chapter argues that ethicists and philosophers of mathematics have misunderstood it. They have confused what the chapter calls the justificatory challenge for realism about an area, D—the (...) challenge to justify our D-beliefs—with the reliability challenge for D-realism—the challenge to explain the reliability of our D-beliefs. Harman’s contrast is relevant to the first, but not, evidently, to the second. One upshot of the discussion is that genealogical debunking arguments are fallacious. Another is that indispensability considerations cannot answer the Benacerraf–Field challenge for mathematical realism. (shrink)

I address Andrew Moon's recent discussion (2016, this journal) of the question whether third-factor accounts are valid responses to debunking arguments against moral realism. Moon argues that third-factor responses are valid under certain conditions but leaves open whether moral realists can use his interpretation of the third-factor response to defuse the evolutionary debunking challenge. I rebut Moon's claim and answer his question. Moon's third-factor reply is valid only if we accept externalism about epistemic defeaters. However, even if we do, I (...) argue, the conditions Moon identifies for a valid third-factor response are not met in the case of moral realism. (shrink)

This paper attempts to specify the conditions under which a psychological explanation can undermine or debunk a set of beliefs. The focus will be on moral and religious beliefs, where a growing debate has emerged about the epistemic implications of cognitive science. Recent proposals by Joshua Greene and Paul Bloom will be taken as paradigmatic attempts to undermine beliefs with psychology. I will argue that a belief p may be undermined whenever: (i) p is evidentially based on an intuition which (...) (ii) can be explained by a psychological mechanism that is (iii) unreliable for the task of believing p; and (iv) any other evidence for belief p is based on rationalization. I will also consider and defend two equally valid arguments for establishing unreliability: the redundancy argument and the argument from irrelevant factors. With this more specific understanding of debunking arguments, it is possible to develop new replies to some objections to psychological debunking arguments from both ethics and philosophy of religion. (shrink)

A number of philosophers have recently claimed that unjustified beliefs can be defeaters. However these claims have been made in passing, occurring in the context of defenses of other theses. As a result, the claim that unjustified beliefs can be defeaters has been neither vigorously defended nor thoroughly explained. This paper fills that gap. It begins by identifying problems with the two most in-depth accounts of the possibility of unjustified defeaters due to Bergmann and Pryor. It then offers a revised (...) version of Pryor’s account. On this proposal, an unjustified belief can be a defeater if it is rational, all things considered. If a belief is rational, all things considered, it can require one to abandon other beliefs with which it conflicts—even if it is unjustified. Finally, this paper shows that the proposed account of unjustified defeaters is one that can and should be embraced by leading accounts of justified belief as diverse as reliabilism and evidentialism. (shrink)

I extend the Higher-Order View of Undermining Defeat (HOVUD) defended in Melis (2014) to account for the defeat of propositional justification. In doing so, I clarify the important notion of higher-order commitment, and I make some considerations concerning the defeat of externalist epistemic warrants.

Scott Sturgeon has recently challenged Pollock’s account of undercutting defeaters. The challenge involves three primary contentions: the account is both too strong and too weak, undercutting defeaters exercise their power to defeat only in conjunction with higher-order beliefs about the basis of the lower-order beliefs whose justification they target, and since rebutting defeaters exercise their power to defeat in isolation, rebutting and undercutting defeaters work in fundamentally different ways. My goal is to reject each of these contentions. I maintain that (...) Sturgeon fails to show that Pollock’s account of undercutting defeaters is either too strong or too weak, his own account of how undercutting defeaters exercise their power to defeat is both too strong and too weak, and his claim that rebutting and undercutting defeaters work in fundamentally different ways is mistaken. (shrink)

One attractive feature of process reliabilism is its reductive potential: it promises to explain justification in entirely non-epistemic terms. In this paper, I argue that the phenomenon of epistemic defeat poses a serious challenge for process reliabilism’s reductive ambitions. The standard process reliabilist analysis of defeat is the ‘Alternative Reliable Process Account’ (ARP). According to ARP, whether S’s belief is defeated depends on whether S has certain reliable processes available to her which, if they had been used, would have resulted (...) in S not holding the belief in question. Unfortunately, ARP proves untenable. I show, by way of counterexample, that ARP fails to articulate either necessary or sufficient conditions on defeat. Process reliabilists must either provide an alternative reductive account of defeat or renounce their reductive aspirations. (shrink)

This paper attempts to specify the conditions under which a psychological explanation can undermine or debunk a set of beliefs. The focus will be on moral and religious beliefs, where a growing debate has emerged about the epistemic implications of cognitive science. Recent proposals by Joshua Greene and Paul Bloom will be taken as paradigmatic attempts to undermine beliefs with psychology. I will argue that a belief p may be undermined whenever: (i) p is evidentially based on an intuition which (...) (ii) can be explained by a psychological mechanism that is (iii) unreliable for the task of believing p; and (iv) any other evidence for belief p is based on rationalization. I will also consider and defend two equally valid arguments for establishing unreliability: the redundancy argument and the argument from irrelevant factors. With this more specific understanding of debunking arguments, it is possible to develop new replies to some objections to psychological debunking arguments from both ethics and philosophy of religion. (shrink)

The question I consider is this: -/- The Question: Can two people–who are, and realize they are, intellectually virtuous to about the same degree–both be rational in continuing knowingly to disagree after full disclosure (by each to the other of all the relevant evidence they can think of) while at the same time thinking that the other may well be rational too? -/- I distinguish two kinds of rationality–internal and external–and argue in section 1 that, whichever kind we have in (...) mind, the answer to The Question is ‘yes’ (though that positive answer is less wholehearted in the case of external rationality). Then, in section 2, I briefly make some more general remarks about when discovering a disagreement provides a defeater and when it doesn't. In the final section, I consider an important objection to the answer given in section 1 to The Question. (shrink)

Evolutionary Debunking Arguments purport to show that our moral beliefs do not amount to knowledge because these beliefs are “debunked” by the fact that our moral beliefs are, in some way, the product of evolutionary forces. But there is a substantial gap in this argument between its main evolutionary premise and the skeptical conclusion. What is it, exactly, about the evolutionary origins of moral beliefs that would create problems for realist views in metaethics? I argue that evolutionary debunking arguments are (...) best understood as offering up defeaters for our moral beliefs. Moreover, the defeater in question is a paradigmatic instance of undercutting defeat. If anything is an undercutting defeater, then learning about the evolutionary origins of our moral beliefs is a defeater for those beliefs. (shrink)

Evolutionary debunking arguments, notably Sharon Street’s Darwinian Dilemma (2006), allege that moral realists need to explain the reliability of our moral judgments, given their evolutionary sources. David Copp (2008) and David Enoch (2010) take up the challenge. I argue on empirical grounds that realists have not met the challenge and moreover cannot do so. The outcome is that there are empirically-motivated reasons for thinking moral realists cannot explain moral reliability, given our current empirical understanding.

Several philosophers have recently argued that evolutionary considerations undermine the justification of all objectivist moral beliefs by implying a hypothetical disagreement: had our evolutionary history been different, our moral beliefs would conflict with the moral beliefs of our counterfactual selves. This paper aims at showing that evolutionary considerations do not imply epistemically relevant moral disagreement. In nearby scenarios, evolutionary considerations imply tremendous moral agreement. In remote scenarios, evolutionary considerations do not entail relevant disagreement with our epistemic peers, neither on a (...) narrow nor on a broad conception of peerhood. In conclusion, evolutionary considerations do not reveal epistemically troubling kinds of disagreement. Anti-objectivists need to look elsewhere to fuel their sceptical argument. (shrink)

Taking the inspiration from some points made by Scott Sturgeon and Albert Casullo, I articulate a view according to which an important difference between undermining and overriding defeaters is that the former require the subject to engage in some higher-order epistemic thinking, while the latter don’t. With the help of some examples, I argue that underminers push the cognizer to reflect on the way she formed a belief by challenging the epistemic worthiness of either the source of justification or the (...) specific justificatory process. By contrast, overriders needn’t pose any such challenge. I also consider some problems for the proposed view, and I put forward some possible solutions. Finally, I provide some details on how undermining defeat works in different cases. (shrink)

It is widely assumed that justification is defeasible, e.g. that under certain conditions counterevidence removes prior justification of beliefs. In this paper I will first (sect. 1) explain why this feature of justification poses a prima facie problem for reliabilism. I then will try out different reliabilist strategies to deal with the problem. Among them I will discuss conservative strategies (sect. 2), eliminativist stragies (sect. 3) and revisionist strategies (sect. 4). In the final section I will present an improved revisionist (...) approach to defeaters that is able to overcome the main shortcomings of the other approaches. (shrink)

Internalists tend to impose on justification higher-level requirements, according to which a belief is justified only if the subject has a higher-level belief (i.e., a belief about the epistemic credentials of a belief). I offer an error theory that explains the appeal of this requirement: analytically, a belief is not justified if we have a defeater for it, but contingently, it is often the case that to avoid having defeaters, our beliefs must satisfy a higher-level requirement. I respond to the (...) objection that externalists who endorse this error theory will be forced to accept a radical form of scepticism. (shrink)