Online research in philosophy

I argue against unqualified acceptance of the principle of deductive closure (DC): that, if p follows deductively from premises that are already known, we are in a position to know p. DC, I claim, is a sorites premise; it seems intuitively irresistible, but indiscriminate application of it leads to absurd conclusions. Furthermore, a theory on which the application of DC is restricted explains our practice of deriving new knowledge from old knowledge better than a theory on which our application of DC is unrestricted. This restriction on the application of DC allows contextualists to meet an argument of Hawthorne’s that contextualism must lead either to absurd knowledge attributions or to constant shifting of the standards for knowledge. Even if the standard of knowledge remains constant, the absurd knowledge attribution is the conclusion of a sorites argument and should be rejected.

Sarah McGrath has recently defended a disagreement-based argument for skepticism about moral knowledge. If sound, the argument shows that our beliefs about controversial moral issues do not amount to knowledge. In this paper, I argue that McGrath fails to establish her skeptical conclusion. I defend two main claims. First, the key premise of McGrath’s argument is inadequately supported. Second, there is good reason to think that this premise is false.

This paper defends the view that standards, which are typically social in nature, play a role in determining whether a subject has knowledge. While the argument focuses on standards that pertain to reasoning, I also consider whether there are similar standards for memory and perception.Ultimately, I argue that the standards are context sensitive and, as such, we must view attributions of knowledge as indexical. I exploit similarities between this view and a version of the relevant alternatives reply to skepticism in order to defend this reply against the objection that it is ad hoc.

I defend a sensitive neo-Moorean invariantism, an epistemological account with the following characteristic features: (a) it reserves a place for a sensitivity condition on knowledge, according to which, very roughly, S’s belief that p counts as knowledge only if S wouldn’t believe that p if p were false; (b) it maintains that the standards for knowledge are comparatively low; and (c) it maintains that the standards for knowledge are invariant (i.e., that they vary neither with the linguistic context of the subject of knowledge nor with the linguistic context of the attributor of knowledge). I argue that this sort of account allows us to respond adequately to some difficult puzzles in epistemology, puzzles such as skeptical puzzles, as well as puzzles that inspire epistemological contextualism. I also maintain that by utilizing what Keith DeRose calls a warranted assertibility maneuver, sensitive neo-Moorean invariantism can account for our epistemic judgments in each of these puzzle cases.

Skeptics try to persuade us of our ignorance with arguments like the following: 1. I dont know that I am not a handless brain-in-a-vat [BIV]. 2. If I dont know that I am not a handless BIV, then I dont know that I have hands. Therefore, 3. I dont know that I have hands. The BIV argument is valid, its premises are intuitively compelling, and yet, its conclusion strikes us as absurd. Something has to go, but what? Contextualists contend that an adequate solution to the skeptical problem must: (i) retain epistemic closure, (ii) explain the intuitive force of skeptical arguments by explaining why their premises initially seem so compelling, and (iii) account for the truth of our commonsense judgment that we do possess lots of ordinary knowledge. Contextualists maintain that the key to such a solution is recognizing that the semantic standards for knows vary from context to context such that in skeptical contexts the skeptics premises are true and so is her conclusion; but in ordinary contexts, her conclusion is false and so is her first premise. Despite its initial attractiveness, the contextualist solution comes at a significant cost, for contextualism has many counterintuitive results. After presenting the contextualist solution, I identify a number of these costs. I then offer a noncontextualist solution that meets the adequacy constraint identified above, while avoiding the costs associated with contextualism. Hence, one of the principal reasons offered for adopting a contextualist theory of knowledge–its supposedly unique ability to adequately resolve the skeptical problem – is undermined.

A: Things that are equal to the same are equal to each other. B: The two sides of this triangle are things that are equal to the same. Z: So, the two sides of this triangle are equal to each other. Achilles fails because he encounters an infinite progression of hidden premises of the form “If all the premises of the argument are true, the conclusion is true”. In [a1], the hidden premise is H1 “If A and B then Z” – surely, if one did not believe that H1 is true, one would have a reason not to accept the conclusion Z. So, the argument [a2] must lead to conclusion Z from A, B and H1. But, one will have to supplement [a2] with H2: “If A and B and H1 then Z” since if one did not believe H2 one would have a reason not to draw conclusion Z. And so on ad infinitum. The puzzle can be seen as arising through the application of an apparently innocent principle of discerning missing premises (§2). If looked at in this light, the standard response given to the paradox does not so much resolve the puzzle as legislates against it being raised with respect to principles of inference (§3). I argue that a fundamental ambiguity infests the test for what is a missing premise (§4). Moreover, it explains why the puzzle appears to, though it does not (§5), arise. I end with some comments on the usefulness of the test (§6).

Skeptics try to persuade us of our ignorance with arguments like the following: 1. I don't know that I am not a handless brain-in-a-vat [BIV]. 2. If I don't know that I am not a handless BIV, then I don't know that I have hands. Therefore, 3. I don't know that I have hands. The BIV argument is valid, its premises are intuitively compelling, and yet, its conclusion strikes us as a absurd. Something has to go, but what? Contextualists contend that an adequate solution to the skeptical problem must: (i) retain epistemic closure, (ii) explain the intuitive force of skeptical arguments by explaining why their premises initially seem so compelling, and (iii) account for the truth of our commonsense judgment that we do possess lots of ordinary knowledge. Contextualists maintain that the key to such a solution is recognizing that the semantic standards for 'knows' vary from context to context such that in skeptical contexts the skeptic's premises are true and so is her conclusion; but in ordinary contexts, her conclusion is false and so is her first premise. Despite its initial attractiveness, the contextualist solution comes at a significant cost, for contextualism has many counterintuitive results. After presenting the contextualist solution, I identify a number of these costs. I then offer a noncontextualist solution that meets the adequacy constraint identified above, while avoiding the costs associated with contextualism. Hence, one of the principal reasons offered for adopting a contextualist theory of knowledge -- its supposedly unique ability to adequately resolve the skeptical problem -- is undermined.

Abstract: It is generally accepted that skeptical scenarios must be possible to raise legitimate skeptical doubt. I argue that if the possibility in question is supposed to be genuine metaphysical possibility, the skeptic's reasoning does not straightforwardly succeed. I first motivate the metaphysical possibility requirement on skeptical scenarios: it's a plausible position that several authors accept and that a family of prominent views—sensitivity, safety, relevant alternatives—are committed to. I argue that plausible constraints in modal epistemology show that justification for believing that certain global skeptical scenarios are metaphysically possible rests on some justified beliefs about the external world, and that this undermines the skeptical argument. While there may still be local skeptical challenges, skeptics cannot appeal to the metaphysical possibility of skeptical scenarios to generate global external world skepticism.

Contextualists claim two important virtues for their view. First, contextualism is a non-skeptical epistemology, given the plausible idea that not all contexts invoke the high standards for knowledge needed to generate the skeptical conclusion that we know little or nothing. Second, contextualism is able to preserve closure concerning knowledge – the idea that knowledge is extendable on the basis of competent deduction from known premises. As long as one keeps the context fixed, it is plausible to think that some closure principle can be articulated that will survive scrutiny. Opponents of contextualism often try to gain an advantage over it by claiming that their view mimics these virtues of contextualism as well as having other virtues. A recent example of the same is termed ‘contrastivism," as presented by Jonathan Schaffer. I will argue that the representation made is chimerical, that in fact contrastivism has no hope of mirroring these twin virtues of contextualism.

In the Meno, Socrates asks why knowledge is a better guide to acting the right way than true belief. The answer he proposes is ingenious, but it fails to solve the puzzle, and some recent attempts to solve it also fail. I shall argue that the puzzle cannot be solved as long as we conceive of knowledge as a kind of belief, or allow our conception of knowledge to be governed by the contrast between knowledge and belief.