In this paper, I defend the heterogeneity problem for sensitivity accounts of knowledge against an objection that has been recently proposed by Wallbridge in Philosophia. I argue in, 479–496, 2015) that sensitivity accounts of knowledge face a heterogeneity problem when it comes to higher-level knowledge about the truth of one’s own beliefs. Beliefs in weaker higher-level propositions are insensitive, but beliefs in stronger higher-level propositions are sensitive. The resulting picture that we can know the stronger propositions without being in a (...) position to know the weaker propositions is too heterogeneous to be plausible. Wallbridge objects that there is no heterogeneity problem because beliefs in the weaker higher-level propositions are also sensitive. I argue against Wallbridge that the heterogeneity problem is not solved but only displaced. Only some beliefs in the weaker higher-level propositions are sensitive. I conclude that the heterogeneity problem is one of a family of instability problems that sensitivity accounts of knowledge face and that Wallbridge’s account raises a further problem of this kind. (shrink)

In a recent paper, Melchior pursues a novel argumentative strategy against the sensitivity condition. His claim is that sensitivity suffers from a ‘heterogeneity problem:’ although some higher-order beliefs are knowable, other, very similar, higher-order beliefs are insensitive and so not knowable. Similarly, the conclusions of some bootstrapping arguments are insensitive, but others are not. In reply, I show that sensitivity does not treat different higher-order beliefs differently in the way that Melchior states and that while genuine bootstrapping arguments have insensitive (...) conclusions, the cases that Melchior describes as sensitive ‘bootstrapping’ arguments don’t deserve the name, since they are a perfectly good way of getting to know their conclusions. In sum, sensitivity doesn’t have a heterogeneity problem. (shrink)

Vogel, Sosa, and Huemer have all argued that sensitivity is incompatible with knowing that you do not believe falsely, therefore the sensitivity condition must be false. I show that this objection misses its mark because it fails to take account of the basis of belief. Moreover, if the objection is modified to account for the basis of belief then it collapses into the more familiar objection that sensitivity is incompatible with closure.

A number of prominent epistemologists claim that the principle of sensitivity “play[s] a starring role in the solution to some important epistemological problems”. I argue that traditional sensitivity accounts fail to explain even the most basic data that are usually considered to constitute their primary motivation. To establish this result I develop Gettier and lottery cases involving necessary truths. Since beliefs in necessary truths are sensitive by default, the resulting cases give rise to a serious explanatory problem for the defenders (...) of sensitivity accounts. It is furthermore argued that attempts to modally strengthen traditional sensitivity accounts to avoid the problem must appeal to a notion of safety—the primary competitor of sensitivity in the literature. The paper concludes that the explanatory virtues of sensitivity accounts are largely illusory. In the framework of modal epistemology, it is safety rather than sensitivity that does the heavy explanatory lifting with respect to Gettier cases, lottery examples, and other pertinent cases. (shrink)

Offering a solution to the skeptical puzzle is a central aim of Nozick's sensitivity account of knowledge. It is well-known that this account faces serious problems. However, because of its simplicity and its explanatory power, the sensitivity principle has remained attractive and has been subject to numerous modifications, leading to a of sensitivity accounts. I will object to these accounts, arguing that sensitivity accounts of knowledge face two problems. First, they deliver a far too heterogeneous picture of higher-level beliefs about (...) the truth or falsity of one's own beliefs. Second, this problem carries over to bootstrapping and Moorean reasoning. Some beliefs formed via bootstrapping or Moorean reasoning are insensitive, but some closely related beliefs in even stronger propositions are sensitive. These heterogeneous results regarding sensitivity do not fit with our intuitions about bootstrapping and Moorean reasoning. Thus, neither Nozick's sensitivity account of knowledge nor any of its modified versions can provide the basis for an argument that bootstrapping and Moorean reasoning are flawed or for an explanation why they seem to be flawed. (shrink)

Since the publication of David Lewis’ Counterfactuals, the standard line on subjunctive conditionals with impossible antecedents (or counterpossibles) has been that they are vacuously true. That is, a conditional of the form ‘If p were the case, q would be the case’ is trivially true whenever the antecedent, p, is impossible. The primary justification is that Lewis’ semantics best approximates the English subjunctive conditional, and that a vacuous treatment of counterpossibles is a consequence of that very elegant theory. Another justification (...) derives from the classical lore than if an impossibility were true, then anything goes. In this paper we defend non-vacuism, the view that counterpossibles are sometimes non-vacuously true and sometimes non-vacuously false. We do so while retaining a Lewisian semantics, which is to say, the approach we favor does not require us to abandon classical logic or a similarity semantics. It does however require us to countenance impossible worlds. An impossible worlds treatment of counterpossibles is suggested (but not defended) by Lewis (Counterfactuals. Blackwell, Oxford, 1973), and developed by Nolan (Notre Dame J Formal Logic 38:325–527, 1997), Kment (Mind 115:261–310, 2006a: Philos Perspect 20:237–302, 2006b), and Vander Laan (In: Jackson F, Priest G (eds) Lewisian themes. Oxford University Press, Oxford, 2004). We follow this tradition, and develop an account of comparative similarity for impossible worlds. (shrink)

The traditional possible-worlds model of belief describes agents as ‘logically omniscient’ in the sense that they believe all logical consequences of what they believe, including all logical truths. This is widely considered a problem if we want to reason about the epistemic lives of non-ideal agents who—much like ordinary human beings—are logically competent, but not logically omniscient. A popular strategy for avoiding logical omniscience centers around the use of impossible worlds: worlds that, in one way or another, violate the laws (...) of logic. In this paper, we argue that existing impossible-worlds models of belief fail to describe agents who are both logically non-omniscient and logically competent. To model such agents, we argue, we need to ‘dynamize’ the impossible-worlds framework in a way that allows us to capture not only what agents believe, but also what they are able to infer from what they believe. In light of this diagnosis, we go on to develop the formal details of a dynamic impossible-worlds framework, and show that it successfully models agents who are both logically non-omniscient and logically competent. (shrink)

What modal relation must a fact bear to a belief in order for this belief to constitute knowledge of that fact? Externalists have proposed various answers, including some that combine externalism with contextualism. We shall find that various forms of externalism share a modal conception of “sensitivity” open to serious objections. Fortunately, the undeniable intuitive attractiveness of this conception can be explained through an easily confused but far preferable notion of “safety.” The denouement of our reflections, finally, will be to (...) show how replacing sensitivity with safety makes it possible to defend plain Moorean common sense against the spurious advantages over it claimed by skeptical, tracking, relevant-alternative, and contextualist accounts. (shrink)

According to Nozick’s tracking theory of knowledge, an agent a knows that p just in case her belief that p is true and also satisfies the two tracking conditionals that had p been false, she would not have believed that p , and had p been true under slightly different circumstances, she would still have believed that p . In this paper I wish to highlight an interesting but generally ignored feature of this theory: namely that it is reminiscent of (...) a dispositional account of knowledge: it invites us to think of knowledge as a manifestation of a cognitive disposition to form true beliefs. Indeed, given a general account of dispositions in terms of subjunctive conditionals, the two tracking conditionals are satisfied just in case the belief in question results from some cognitive disposition to form true beliefs. Recently, such a conditional account of dispositions has, however, been criticised for its vulnerability to so-called ‘masked’, ‘mimicked’ and ‘finkish’ counterexamples. I show how the classical counterexamples to Nozick’s theory divide smoothly into four corresponding categories of counterexamples from epistemic masking, mimicking and finkishness. This provides strong evidence for the thesis that satisfaction of the two tracking conditionals is symptomatic of knowledge and that knowledge is instead constituted by a dispositional capability to form true beliefs. The attempt to capture such a cognitive, dispositional capability in terms of the tracking conditionals, although providing a good approximation in a wide variety of cases, still comes apart from the real thing whenever the epistemic layout is characterised by masking-, mimicking- and finkish mechanisms. In the last part of the paper I explore the prospect of improving the tracking theory in the light of these findings. (shrink)

Jonathan Vogel has recently argued that counterfactual reliabilism cannot account for higher‐level knowledge that one's belief is true, or not false. His particular argument for this claim is straightforward and valid. Interestingly, there is a parallel argument, based on an alternative but plausible reinterpretation of the main premise in Vogel's argument, which squares CR with higher‐level knowledge both that one's belief is true and that one's belief is not false. I argue that, while Vogel's argument reveals the incompatibility of CR (...) and knowledge of certain higher‐level propositions, it does not establish the general claim that CR is incompatible with knowledge that any of one's beliefs is true, or not false. (shrink)