Traditional procedures for rational updating fail when it comes to self-locating opinions, such as your credences about where you are and what time it is. This paper develops an updating procedure for rational agents with self-locating beliefs. In short, I argue that rational updating can be factored into two steps. The first step uses information you recall from your previous self to form a hypothetical credence distribution, and the second step changes this hypothetical distribution to reflect information you have genuinely (...) learned as time has passed. While the second step resembles traditional procedures of updating by conditionalization, the first is best understood by analogy to traditional models of how agents transmit self-locating opinions through ordinary interpersonal communication. (shrink)

A fundamental question asked in modal logic is whether a given theory is consistent. But consistent with what? A typical way to address this question identifies a choice of background knowledge axioms (say, S4, D, etc.) and then shows the assumptions codified by the theory in question to be consistent with those background axioms. But determining the specific choice and division of background axioms is, at least sometimes, little more than tradition. This paper introduces generic theories for propositional modal logic (...) to address consistency results in a more robust way. As building blocks for background knowledge, generic theories provide a standard for categorical determinations of consistency. We argue that the results and methods of this paper help to elucidate problems in epistemology and enjoy sufficient scope and power to have purchase on problems bearing on modalities in judgement, inference, and decision making. (shrink)

The thesis that knowledge is a factive mental state plays a central role in knowledge-first epistemology, but accepting this thesis requires also accepting an unusually severe version of externalism about the mind. On this strong attitude externalism, whether S is in the mental state of knowledge can and often will rapidly change in virtue of changes in external states of reality with which S has no causal contact. It is commonly thought that this externalism requirement originates in the factivity of (...) knowledge. However, despite a number of recent defenses of non-factive accounts of knowledge, epistemology has yet to consider whether a non-factive approach might produce a version of the mental state thesis that can avoid strong externalism. Here I do just that, exploring how three different proposals for weakening factivity might be adapted to theories of knowledge as a non-factive mental state. Contrary to what we might expect, however, none of these proposals are compatible with anything close to attitude internalism about knowledge—or even a substantially weaker externalism. All told, the widespread view that wraps up the severe externalism required for knowledge to be a mental state in factivity is mistaken. Knowledge’s external-world connection runs far deeper than the factivity constraint. (shrink)

Fitch's Paradox and the Paradox of the Knower both make use of the Factivity Principle. The latter also makes use of a second principle, namely the Knowledge-of-Factivity Principle. Both the principle of factivity and the knowledge thereof have been the subject of various discussions, often in conjunction with a third principle known as Closure. In this paper, we examine the well-known Surprise Examination paradox considering both the principles on which this paradox rests and some formal characterisations of the surprise notion, (...) crucial in this paradox. Standard formalizations of the Surprise Examination paradox in modal logic do not seem, at first glance, to depend on either factivity or knowledge-of-factivity, but we will argue that both factivity and knowledge-of-factivity play a key implicit role in the paradox. Namely, they are implicitly, perhaps unintentionally, used in order to simplify the definition of surprise. We analyze modal logical formalizations of three versions of the paradox concluding that the Surprise Examination paradox is the result of two flaws: the assumption of knowledge-of-factivity, and the over-simplification of the definition of "surprise" accordingly. By fixing these two flaws, the Surprise Examination paradox vanishes. (shrink)

Fitch’s Paradox shows that if every truth is knowable, then every truth is known. Standard diagnoses identify the factivity/negative infallibility of the knowledge operator and Moorean contradictions as the root source of the result. This paper generalises Fitch’s result to show that such diagnoses are mistaken. In place of factivity/negative infallibility, the weaker assumption of any ‘level-bridging principle’ suffices. A consequence is that the result holds for some logics in which the “Moorean contradiction” commonly thought to underlie the result is (...) in fact consistent. This generalised result improves on the current understanding of Fitch’s result and widens the range of modalities of philosophical interest to which the result might be fruitfully applied. Along the way, we also consider a semantic explanation for Fitch’s result which answers a challenge raised by Kvanvig. (shrink)

One diagnosis of Fitch’s paradox of knowability is that it hinges on the factivity of knowledge: that which is known is true. Yet the apparent role of factivity and non-factive analogues in related paradoxes of justified belief can be shown to depend on familiar consistency and positive introspection principles. Rejecting arguments that the paradox hangs on an implausible consistency principle, this paper argues instead that the Fitch phenomenon is generated both in epistemic logic and logics of justification by the interaction (...) of analogues of the knowability principle and positive introspection theses that are characteristic of, even if not entailed by, epistemic internalism. (shrink)

Several philosophers have argued that the factivity of knowledge poses a problem for epistemic contextualism (EC), which they have construed as a knowability problem. On a proposed minimalistic reading of EC’s commitments, Wolfgang Freitag argues that factivity yields no knowability problem for EC. I begin by explaining how factivity is thought to generate a contradiction out of paradigmatic contextualist cases on a certain reading of EC’s commitments. This reductio results in some kind of reflexivity problem for the contextualist when it (...) comes to knowing her theory: either a knowability problem or a statability problem. Next, I set forth Freitag’s minimalistic reading of EC and explain how it avoids the reductio, the knowability problem and the statability problem. I argue that despite successfully evading these problems, Freitag’s minimalistic reading saddles EC with several other serious problems and should be rejected. I conclude by offering my own resolution to the problems. (shrink)

This paper argues that just as full beliefs can constitute knowledge, so can properties of your credence distribution. The resulting notion of probabilistic knowledge helps us give a natural account of knowledge ascriptions embedding language of subjective uncertainty, and a simple diagnosis of probabilistic analogs of Gettier cases. Just like propositional knowledge, probabilistic knowledge is factive, safe, and sensitive. And it helps us build knowledge-based norms of action without accepting implausible semantic assumptions or endorsing the claim that knowledge is interest-relative.

This paper examines, and rejects, a recent argument to the effect that knowledge is not truth-entailing, i.e. that “know” is not factive.