It is widely thought that if knowledge requires sensitivity, knowledge is not closed because sensitivity is not closed. This paper argues that there is no valid argument from sensitivity failure to non-closure of knowledge. Sensitivity does not imply non-closure of knowledge. Closure considerations cannot be used to adjudicate between safety and sensitivity accounts of knowledge.

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.

Knowledge and its Limits presents a systematic new conception of knowledge as a kind of mental stage sensitive to the knower's environment. It makes a major contribution to the debate between externalist and internalist philosophies of mind, and breaks radically with the epistemological tradition of analyzing knowledge in terms of true belief. The theory casts new light on such philosophical problems as scepticism, evidence, probability and assertion, realism and anti-realism, and the limits of what can be known. The arguments are (...) illustrated by rigorous models based on epistemic logic and probability theory. The result is a new way of doing epistemology and a notable contribution to the philosophy of mind. (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)

This book develops and defends a version of direct realism: the thesis that perception gives us direct awareness, and non-inferential knowledge, of the external..

The sensitivity principle is a compelling idea in epistemology and is typically characterized as a necessary condition for knowledge. This collection of thirteen new essays constitutes a state-of-the-art discussion of this important principle. Some of the essays build on and strengthen sensitivity-based accounts of knowledge and offer novel defences of those accounts. Others present original objections to sensitivity-based accounts and offer comprehensive analysis and discussion of sensitivity's virtues and problems. The resulting collection will stimulate new debate about the sensitivity principle (...) and will be of great interest and value to scholars and advanced students of epistemology. (shrink)

The sensitivity condition on knowledge says that one knows that P only if one would not believe that P if P were false. Difficulties for this condition are now well documented. Keith DeRose has recently suggested a revised sensitivity condition that is designed to avoid some of these difficulties. We argue, however, that there are decisive objections to DeRose’s revised condition. Yet rather than simply abandoning his proposed condition, we uncover a rationale for its adoption, a rationale which suggests a (...) further revision that avoids our objections as well as others. The payoff is considerable: along the way to our revision, we learn lessons about the epistemic significance of certain explanatory relations, about how we ought to envisage epistemic closure principles, and about the epistemic significance of methods of belief formation. (shrink)

In this paper it is argued that sensitivity theory suffers from a fatal defect. Sensitivity theory is often glossed as: (1) S knows that p only if S would not believe that p if p were false. As Nozick showed in his pioneering work on sensitivity theory, this formulation needs to be supplemented by a further counterfactual condition: (2) S knows that p only if S would believe p if p were true. Nozick further showed that the theory needs a (...) qualification on the method used to form the belief. However, when these complications are spelled out in detail, it becomes clear that the two counterfactuals are in irresolvable tension. To jibe with the externalist intuitions that motivate sensitivity theory in the first place, (1) needs a fine-grained grouping of belief-formation methods, but (2) needs coarse-grained grouping. It is therefore suggested that sensitivity theory is in dire straits: either its proponents need to provide a workable principle of method individuation or they must retrench and give up their claims to providing sufficient conditions for knowledge. (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)

In “Reliabilism Leveled” Jonathan Vogel (2000) provides a strong case against epistemic theories that stress the importance of tracking/sensitivity conditions. A tracking/sensitivity condition is to be understood as some version of the following counterfactual: (T) ~p oÆ ~Bp (T) says that s would not believe p, if p were false. Among other things, tracking is supposed to express the external relation that explains why some justified true beliefs are not knowledge. Champions of the condition include Robert Nozick (1981) and, more (...) recently, Keith DeRose (1995). To my knowledge, the earliest formulation of the counterfactual condition is found in Fred Dretske’s conclusive reasons condition (1971), which says, s would not have had the reason that she does for believing p, if p were false. Vogel contends that any such counterfactual condition on knowledge will render the theory of knowledge too strong. He believes that there is at least some possible reflective knowledge that cannot satisfy the counterfactual--viz., the possible knowledge that one does not believe falsely that p. The alleged impossibility of such reflective knowledge is taken by Vogel to be a decisive objection to the tracking theories advocated by Dretske, Nozick, DeRose1 and others. The criticism finds its roots in Vogel’s earlier work (1987), and recurs in papers by Ernest Sosa (2002, 1996). Sosa suggests that the externalist idea behind tracking is on target, but that Nozick’s counterfactual is a misbegotten regimentation of the idea. In its place Sosa offers his own counterfactual “safety” condition, which he feels properly captures the externalist idea. Sosa’s counterfactual is not the topic of this paper. I mention it only to point out that the criticism that constitutes the subject of my investigation is meant to do a lot of work. In Sosa’s 1 case the criticism is meant to motivate his own counterfactual analysis, and in Vogel’s case the criticism promises to be a silver bullet against a theory that has recently found renewed life in the work of Keith DeRose.. (shrink)

Subjunctivitis is the doctrine that what is distinctive about knowledge is essential modal in character, and thus is captured by certain subjunctive conditionals. One principal formulation of subjunctivism invokes a ``sensitivity condition'' (Nozick, De Rose), the other invokes a ``safety condition'' (Sosa). It is shown in detail how defects in the sensitivity condition generate unwanted results, and that the virtues of that condition are merely apparent. The safety condition is untenable also, because it is too easily satisfied. A powerful motivation (...) for adopting subjunctivism would be that it provides a solution to the problem of misleading evidence, but in fact, it does not. (shrink)