The Knower Paradox and Epistemic Closure

The Knower Paradox has had a brief but eventful history, and principles of epistemic closure (which say that a subject automatically knows any proposition she knows to be materially implied, or logically entailed, by a proposition she already knows) have been the subject of tremendous debate in epistemic logic and epistemology more generally, especially because the fate of standard arguments for and against skepticism seems to turn on the fate of closure. As far as I can tell, however, no one working in either area has emphasized the result I emphasize in this paper: the Knower Paradox just falsifies even the most widely accepted general principles of epistemic closure. After establishing that result, I discuss five of its more important consequences.     

Problems for contrastive closure: resolved and regained

The standard contextualist solution to the skeptical paradox is intended to provide a way to retain epistemic closure while avoiding the excessive modesty of radical skepticism and the immodesty of Moorean dogmatism. However, contextualism’s opponents charge that its solution suffers from epistemic immodesty comparable to Moorean dogmatism. According to the standard contextualist solution, all contexts where an agent knows some ordinary proposition to be true are contexts where she also knows that the skeptical hypotheses are false. It has been hoped that contrastivist theories of knowledge can mirror the contextualist solution while avoiding this epistemic immodesty. I review the main problems for contrastive closure and argue that none of the arguments currently in the literature pose an insurmountable problem for the contrastivist solution. However, I argue that contrastivist theories of knowledge, like their contextualist rivals, are indeed committed to epistemic immodesty.     

Skeptical Conclusions

For a putative knower S and a proposition P, two types of skepticism can be distinguished, depending on the conclusions they draw: outer skepticism, which concludes that S does not know that P, and inner skepticism, which concludes that S does not know whether P. This paper begins by showing that outer skepticism has undesirable consequences because that S does not know that P presupposes P, and inner skepticism does not have this undesirable consequence since that S does not know whether P does not presuppose P. We indicate that the two types of skepticism aim to different loci of doubts: while outer skepticism doubts whether we can gain an epistemic warrant for the actuality, inner skepticism doubts whether we can gain epistemic identification of the actuality. It is further indicated that responses to skepticism from externalist theories, as well as from fallibilist internalist theories, can only respond to outer skepticism but not to inner skepticism.     

A Noetic Theory of Understanding and Intuition as Sense-Maker

Abstract

The notion of a non-sensory mental state or event that plays a prominent role in coming to understand, an epistemic achievement distinct from mere knowledge, featured prominently in historical writings on philosophy, and philosophical methodology. It is, however, completely absent from contemporary discussions of the subject. This paper argues that intuition plays an epistemic role in understanding, including philosophical understanding, and offers an explanation of how intuition manages to play this role, if and when it does. It is argued, subsequently, that this role is autonomous, in the sense that a source of understanding cannot be reduced to a source of justification, evidence, or reason. Finally, it is noted that such autonomy implies that popular forms of skepticism about intuition do not impugn intuition’s epistemic significance with respect to its status as a source of understanding.     

On nonindexical contextualism

MacFarlane distinguishes “context sensitivity” from “indexicality,” and argues that “nonindexical contextualism” has significant advantages over the standard indexical form. MacFarlane’s substantive thesis is that the extension of an expression may depend on an epistemic standard variable even though its content does not. Focusing on ‘knows,’ I will argue against the possibility of extension dependence without content dependence when factors such as meaning, time, and world are held constant, and show that MacFarlane’s nonindexical contextualism provides no advantages over indexical contextualism. The discussion will shed light on the definition of indexicals as well as the meaning of ‘knows,’ and highlight important constraints on the way meaning can be represented in semantics.     

What we talk about when we talk about epistemic justification

Stewart Cohen argues that much contemporary epistemological theorizing is hampered by the fact that ‘epistemic justification’ is a term of art (rather than something we all pretheoretically understand) and one that is never given any serious explication in a non-tendentious, theory-neutral way. He suggests that epistemologists are therefore better off theorizing in terms of rationality, rather than in terms of ‘epistemic justification’. Against this, I argue that even if the term ‘epistemic justification’ is not broadly known, the concept it picks out is quite familiar, and partly because it’s a term of art, justification talk is a better vehicle for philosophical theorizing. ‘Rational’ is too unclear for our philosophical purposes, and the fact that ‘epistemic justification’ gets fleshed out by appeal to substantive, controversial theses is no obstacle to its playing the needed role in epistemological theorizing.     

Forgetting memory skepticism

Memory skepticism denies our memory beliefs could have any notable epistemic good. One route to memory skepticism is to challenge memory’s epistemic trustworthiness, that is, its functioning in a way necessary for it to provide epistemic justification. In this paper we develop and respond to this challenge. It could threaten memory in such a way that we altogether lack doxastic attitudes. If it threatens memory in this way, then the challenge is importantly self-defeating. If it does not threaten memory in this way, then the challenge leaves a foundation for an inference to the best explanation response, one we articulate and support.     

Epistemic contextualism defended

Epistemic contextualists think that the extension of the expression ‘knows’ (and its cognates) depends on and varies with the context of utterance. In the last 15 years or so this view has faced intense criticism. This paper focuses on two sorts of objections. The first are what I call the ‘linguistic objections’, which purport to show that the best available linguistic evidence suggests that ‘knows’ is not context-sensitive. The second is what I call the ‘disagreement problem’, which concerns the behaviour of ‘knows’ in disagreement reports. These may not be the only objections to epistemic contextualism, but they are probably the most influential. I argue that the best current epistemic contextualist response to the linguistic objection is incomplete, and I show how it can be supplemented to deal with the full range of linguistic objections. I also develop a new solution to the disagreement problem. The upshot is that neither sort of objection gives us any reason to reject epistemic contextualism. This conclusion is, in a sense, negative—no new arguments for epistemic contextualism are advanced—but it’s a vital step towards rehabilitating the view.     

Undermining, circularity, and disagreement

Sometimes we get what seem to be good reasons for believing that we’ve misevaluated our evidence for a proposition P. In those cases, can we use our evidence for P itself to show that we haven’t misevaluated our evidence for P? I show why doing so appears to employ viciously circular reasoning. However, I then argue that this appearance is illusory in certain cases and that we sometimes can legitimately reason in that way. This claim sheds new light on the nature of epistemic undermining and epistemic circularity. In addition, it has implications for the current debate about the epistemic significance of disagreement. An important and influential position in that debate says that disagreement with others dramatically undermines our justification for a wide range of our opinions (e.g., political, religious, moral, economic, and philosophical opinions). My view on undermining and circularity implies that this position on disagreement rests on a mistake.     

The Relatively Happy Fish

Zhuangzi and Hui Shi's discussion about whether Zhuangzi knows ‘fish’s happiness' is a Daoist staple. The interpretations, however, portray it as humorous miscommunication between a mystic and a logician. I argue for a fine inferential analysis that explains the argument in a way that informs Zhuangzi philosophical lament at Hui Shi's passing. It also reverses the dominant image of the two thinkers. Zhuangzi emerges as the superior dialectician, the clearer, more analytic epistemologist. Hui Shi's arguments betray his tendency (manifest elsewhere) to misstate the conclusions of their shared relativism leading him but not Zhuangzi to intuitive mysticism.     

Knowledge,Presupposition, and Pragmatic Implicature

It is widely accepted that knowledge is factive, but two different understandings of ＂factivity＂ should be distinguished, namely, the implication version and the presupposition version. While the former only takes the truth of P as a necessary requirement for ＂S knows that P,＂ the latter considers it also necessary for ＂S does not know that P.＂ In this paper, I argue against presupposition and defend implication. More specifically, I argue against Wang and Tai＇s defense of the presupposition version as presented in a recent paper and propose a pragmatic response to the ＂persistence problem＂ of implication. In other words, my positive proposal is an account of implication plus pragmatic implicature. To conclude, I use my version to analyze Wang and Tai＇s distinction between inner skepticism and outer skepticism. My conclusion is that, after abandoning presupposition, we can identify two types of intermediate skepticism between Wang and Tai＇s inner and outer skepticism.     

Logic and Social Cognition

This article takes off from Johan van Benthem’s ruminations on the interface between logic and cognitive science in his position paper “Logic and reasoning: Do the facts matter?”. When trying to answer Van Benthem’s question whether logic can be fruitfully combined with psychological experiments, this article focuses on a specific domain of reasoning, namely higher-order social cognition, including attributions such as “Bob knows that Alice knows that he wrote a novel under pseudonym”. For intelligent interaction, it is important that the participants recursively model the mental states of other agents. Otherwise, an international negotiation may fail, even when it has potential for a win-win solution, and in a time-critical rescue mission, a software agent may depend on a teammate’s action that never materializes. First a survey is presented of past and current research on higher-order social cognition, from the various viewpoints of logic, artificial intelligence, and psychology. Do people actually reason about each other’s knowledge in the way proscribed by epistemic logic? And if not, how can logic and cognitive science productively work together to construct more realistic models of human reasoning about other minds? The paper ends with a delineation of possible avenues for future research, aiming to provide a better understanding of higher-order social reasoning. The methodology is based on a combination of experimental research, logic, computational cognitive models, and agent-based evolutionary models.     

Memory as a Generative Epistemic Source

It is widely assumed that memory has only the capacity to preserve epistemic features that have been generated by other sources. Specifically, if S knows (justifiedly believes/rationally believes) that p via memory at T2, then it is argued that (i) S must have known (justifiedly believed/rationally believed) that p when it was originally acquired at T1, and (ii) S must have acquired knowledge that p (justification with respect to p/rationality with respect to p) at T1 via a non-memorial source. Thus, according to this view, memory cannot make an unknown proposition known, an unjustified belief justified, or an irrational belief rational–it can only preserve what is already known, justified, or rational. In this paper, I argue that condition (i) is false and, a fortiori , that condition (ii) is false. Hence, I show that, contrary to received wisdom in contemporary epistemology, memory can function as a generative epistemic source.     

Fallibilism,Contextualism and Second‐Order Skepticism

Fallibilism is ubiquitous in contemporary epistemology. I argue that a paradox about knowledge, generated by considerations of truth, shows that fallibilism can only deliver knowledge in lucky circumstances. Specifically, since it is possible that we are brains‐in‐vats (BIVs), it is possible that all our beliefs are wrong. Thus, the fallibilist can know neither whether or not we have much knowledge about the world nor whether or not we know any specific proposition, and so the warrant of our knowledge‐claims is much reduced and second‐order skepticism is generated. Since this is the case in both skeptical and everyday contexts, contextualism cannot resolve the paradox.     

Inclusiveness in the face of anticipated disagreement

This paper discusses the epistemic outcomes of following a belief-forming policy of inclusiveness under conditions in which one anticipates systematic disagreement with one’s interlocutors. These cases highlight the possibility of distinctly epistemic costs of inclusiveness, in the form of lost knowledge of or a diminishment in one’s rational confidence in a proposition. It is somewhat controversial whether following a policy of inclusiveness under such circumstances will have such costs; this will depend in part on the correct account of the epistemic significance of disagreement (a topic over which there is some disagreement). After discussing this matter at some length, I conclude, tentatively, that inclusiveness under disagreement can have such epistemic costs. Still, I go on to argue, such costs by themselves would not rationalize substantial limitations on a broad policy of inclusiveness. Insofar as there are grounds for restricting how inclusive one should be in belief-formation, these grounds will not be epistemic, but instead will reflect the practical costs—the time, effort, and resource costs to the subject—of following such a policy.     

Problems in Epistemic Space

When a proposition might be the case, for all an agent knows, we can say that the proposition is epistemically possible for the agent. In the standard possible worlds framework, we analyze modal claims using quantification over possible worlds. It is natural to expect that something similar can be done for modal claims involving epistemic possibility. The main aim of this paper is to investigate the prospects of constructing a space of worlds—epistemic space—that allows us to model what is epistemically possible for ordinary, non-ideally rational agents like you and me. I will argue that the prospects look dim for successfully constructing such a space. In turn, this will make a case for the claim that we cannot use the standard possible worlds framework to model what is epistemically possible for ordinary agents.     

A strategy for assessing closure

This paper looks at an argument strategy for assessing the epistemic closure principle. This is the principle that says knowledge is closed under known entailment; or (roughly) if S knows p and S knows that p entails q, then S knows that q. The strategy in question looks to the individual conditions on knowledge to see if they are closed. According to one conjecture, if all the individual conditions are closed, then so too is knowledge. I give a deductive argument for this conjecture. According to a second conjecture, if one (or more) condition is not closed, then neither is knowledge. I give an inductive argument for this conjecture. In sum, I defend the strategy by defending the claim that knowledge is closed if, and only if, all the conditions on knowledge are closed. After making my case, I look at what this means for the debate over whether knowledge is closed.     

Substantive assumptions in interaction: a logical perspective

In this paper we study substantive assumptions in social interaction. By substantive assumptions we mean contingent assumptions about what the players know and believe about each other’s choices and information. We first explain why substantive assumptions are fundamental for the analysis of games and, more generally, social interaction. Then we show that they can be compared formally, and that there exist contexts where no substantive assumptions are being made. Finally we show that the questions raised in this paper are related to a number of issues concerning “large” structures in epistemic game theory.     

Anti-Skepticism Under a Linguistic Guise

In this paper I consider the plausibility of developing anti-skepticism by framing the question in linguistic terms: instead of asking whether we know, we ask what falls within the extension of the word “know”. I first trace two previous attempts to develop anti-skepticism in this way, from Austin (particularly as presented by Kaplan) and from epistemic contextualism, and I present reasons to think that both approaches are unsuccessful. I then focus on a recently popular attempt to develop anti-skepticism from the “function-first” approach associated with Craig, which I also show to be problematic. I then argue that the apparent prima facie plausibility of fighting skepticism on linguistic grounds is due to a methodological spill-over from linguistics. Once we recognize this, it becomes clear that the skepticism debate should not be conducted in linguistic terms.