One of the most recent trends in epistemology is contrastivism. It can be characterized as the thesis that knowledge is a ternary relation between a subject, a proposition known and a contrast proposition. According to contrastivism, knowledge attributions have the form “S knows that p, rather than q”. In this paper I raise several problems for contrastivism: it lacks plausibility for many cases of knowledge, is too relaxed concerning the third relatum, and overlooks a further relativity of the knowledge relation.

According to the received view in epistemology, inferential knowledge from non-knowledge is impossible – that is, in order for a subject to know the conclusion of their inference, they must know the essential premises from which that conclusion is drawn. In this book, Federico Luzzi critically examines this view, arguing that it is less plausible than intuition suggests and that it can be abandoned without substantial cost. In a discussion that ranges across inference, testimony and memory he analyses the full (...) range of challenges to the view, connecting them to epistemological cases that support those challenges. He then proposes a defeater-based framework which allows the phenomenon of knowledge from non-knowledge across these three epistemic areas to be better understood. His book will be of interest to a wide range of readers in epistemology. (shrink)

This book is primarily about checking and only derivatively about knowing. Checking is a very common concept for describing a subject’s epistemic goals and actions. Surprisingly, there has been no philosophical attention paid to the notion of checking. In Part I, I develop a sensitivity account of checking. To be more explicit, I analyze the internalist and externalist components of the epistemic action of checking which include the intentions of the checking subject and the necessary externalist features of the method (...) used. Crucially, successfully checking whether p is true requires using a method that is sensitive with respect to p, i.e. a method that would not indicate that p, if p were false. In Part II, I use the distinction between knowing and checking to explain central puzzles about knowledge, particularly puzzles centering on knowledge closure, puzzles concerning bootstrapping and the skeptical puzzle. Moreover, the book clarifies a dispute about modal epistemology, concerning the application of the sensitivity principle. By arguing that sensitivity is necessary for checking but not knowing, I explain where our persisting intuitions about sensitivity have their place in epistemology. (shrink)

How should the contrastivist formulate closure? That is, given that knowledge is a ternary contrastive state Kspq (s knows that p rather than q), how does this state extend under entailment? In what follows, I will identify adequacy conditions for closure, criticize the extant invariantist and contextualist closure schemas, and provide a contrastive schema based on the idea of extending answers. I will conclude that only the contrastivist can adequately formulate closure.

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)

This paper presents a partial analysis of perceptual knowledge, an analysis that will, I hope, lay a foundation for a general theory of knowing. Like an earlier theory I proposed, the envisaged theory would seek to explicate the concept of knowledge by reference to the causal processes that produce (or sustain) belief. Unlike the earlier theory, however, it would abandon the requirement that a knower's belief that p be causally connected with the fact, or state of affairs, that p.

Nozick analyzes fundamental issues, such as the identity of the self, knowledge and skepticism, free will, the foundations of ethics, and the meaning of life.

Vogel argues that sensitivity accounts of knowledge are implausible because they entail that we cannot have any higher-level knowledge that our beliefs are true, not false. Becker and Salerno object that Vogel is mistaken because he does not formalize higher-level beliefs adequately. They claim that if formalized correctly, higher-level beliefs are sensitive, and can therefore constitute knowledge. However, these accounts do not consider the belief-forming method as sensitivity accounts require. If we take bootstrapping as the belief-forming method, as the discussed (...) cases suggest, then we face a generality problem. Our higher-level beliefs as formalized by Becker and Salerno turn out to be sensitive according to a wide reading of bootstrapping, but insensitive according to a narrow reading. This particular generality problem does not arise for the alternative accounts of process reliabilism and basis-relative safety. Hence, sensitivity accounts not only deliver opposite results given different formalizations of higher-level beliefs, but also for the same formalization, depending on how we interpret bootstrapping. Therefore, sensitivity accounts do not fail because they make higher-level knowledge impossible, as Vogel argues, and they do not succeed in allowing higher-level knowledge, as Becker and Salerno suggest. Rather, their problem is that they deliver far too heterogeneous results. (shrink)

This article gives an overview over different principles of epistemic closure, their attractions and their problems.