This paper takes on several distinct but related tasks. First, I present and discuss what I will call the “Ignorance Thesis,” which states that whenever an agent acts from ignorance, whether factual or moral, she is culpable for the act only if she is culpable for the ignorance from which she acts. Second, I offer a counterexample to the Ignorance Thesis, an example that applies most directly to the part I call the “Moral Ignorance Thesis.” Third, I argue for a (...) principle—Don’t Know, Don’t Kill—that supports the view that the purported counterexample actually is a counterexample. Finally, I suggest that my arguments in this direction can supply a novel sort of argument against many instances of killing and eating certain sorts of animals. (shrink)

This book is a defense of modal realism; the thesis that our world is but one of a plurality of worlds, and that the individuals that inhabit our world are only a few out of all the inhabitants of all the worlds. Lewis argues that the philosophical utility of modal realism is a good reason for believing that it is true.

Rik Peels has once again forcefully argued that ignorance is not equivalent to the lack or absence of knowledge. In doing so, he endeavors to refute the Standard View of Ignorance according to which they are equivalent, and to advance what he calls the “New View” according to which ignorance is equivalent (merely) to the lack or absence of true belief. I defend the Standard View against his new attempted refutation.

This article offers an analysis of ignorance. After a couple of preliminary remarks, I endeavor to show that, contrary to what one might expect and to what nearly all philosophers assume, being ignorant is not equivalent to failing to know, at least not on one of the stronger senses of knowledge. Subsequently, I offer two definitions of ignorance and argue that one’s definition of ignorance crucially depends on one’s account of belief. Finally, I illustrate the relevance of my analysis by (...) paying attention to four philosophical problems in which ignorance plays a crucial role. (shrink)

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)

Against the traditional view, Alvin Goldman argues that logic, probability theory, and linguistic analysis cannot by themselves delineate principles of rationality or justified belief. The mind's operations must be taken into account.

Dynamic Epistemic Logic This article tells the story of the rise of dynamic epistemic logic, which began with epistemic logic, the logic of knowledge, in the 1960s. Then, in the late 1980s, came dynamic epistemic logic, the logic of change of knowledge. Much of it was motivated by puzzles and paradoxes. The number … Continue reading Dynamic Epistemic Logic →.

The point of the present paper is to draw attention to some interesting similarities, as well as differences, between the approaches to the logic of noncontingency of Evgeni Zolin and of Claudio Pizzi. Though neither of them refers to the work of the other, each is concerned with the definability of a (normally behaving, though not in general truth-implying) notion of necessity in terms of noncontingency, standard boolean connectives and additional but non-modal expressive resources. The notion of definability involved is (...) different in the two cases (‘external’ for Zolin, ‘internal’ for Pizzi), as are the additional resources: infinitary conjunction in the case of Zolin, and for Pizzi, first, propositional quantification, and then, later, most ingeniously, the use of a propositional constant. As well as surveying and comparing of the work of these authors, the discussion includes some some novelties, such as the confirmation of a conjecture of Zolin’s (Theorem 2.7). (shrink)

We discuss presupposition, the phenomenon whereby speakers mark linguistically the information that is presupposed or taken for granted, rather than being part of the main propositional content of a speech act. Expressions and constructions carrying presuppositions are called “presupposition triggers”, forming a large class including definites and factive verbs. The article first introduces the range of triggers, the basic properties of presuppositions such as projection and cancellability, and the diagnostic tests used to identify them. The reader is then introducedto major (...) models of presupposition from the last 50 years, separated into three classes: Frege-Strawson derived semantic models, pragmaticmodels such as that offered by Stalnaker, and dynamic models. Finallywe discuss some of the main current issues in presupposition theory. These involve accommodation, which occurs when a hearer's knowledge state is adjusted to meet the speaker's presuppositions; presupposition failure, which occurs when a presupposition is false; the interaction between presuppositions and attitudes; and the triggering problem, i.e., the problem of explaining why presuppositions occur in the first place. (shrink)

In this paper, I respond to Pierre Le Morvan’s critique of my thesis that ignorance is lack of true belief rather than absence of knowledge. I argue that the distinction between dispositional and non-dispositional accounts of belief, as I made it in a previous paper, is correct as it stands. Also, I criticize the viability and the importance of Le Morvan’s distinction between propositional and factive ignorance. Finally, I provide two arguments in favor of the thesis that ignorance is lack (...) of true belief rather than absence of knowledge. (shrink)

This superbly crafted account of the notion of moral responsibility and of its relations to freedom, control, ignorance, negligence, attempts, omissions, compulsion, mental disorders, virtues and vices, desert, and punishment fills that gap. The treatment of character and luck is particularly sophisticated and well-argued.

Dynamic Epistemic Logic is the logic of knowledge change. This book provides various logics to support such formal specifications, including proof systems. Concrete examples and epistemic puzzles enliven the exposition. The book also offers exercises with answers. It is suitable for graduate courses in logic. Many examples, exercises, and thorough completeness proofs and expressivity results are included. A companion web page offers slides for lecturers and exams for further practice.

Rik Peels has ingeniously argued that ignorance is not equivalent to the lack or absence of knowledge. In this response, I defend the Standard View of Ignorance according to which they are equivalent. In the course of doing so, some important lessons will emerge concerning the nature of ignorance and its relationship to knowledge.

Ever since at least Aristotle, it has been widely recognized that a theory of responsibility must allow for the fact that in certain conditions agents are excused for not doing what they ought to do —and accordingly that they cannot be held responsible for what they did not, or did, do. In such conditions they are not appropriate candidates for one of what Strawson has called the "reactive attitudes" such as resentment, contempt, gratitude, and affection. Let us call such conditions (...) excusing conditions. The main aim of this paper is to show that the very same conditions that can excuse agents for not doing what they ought to do , also can excuse them for having false beliefs. As an afterthought it is suggested that this is a reason for thinking that humans can sometimes be held responsible for what they believe. (shrink)

In this paper, I provide a defence of the New View, on which ignorance is lack of true belief rather than lack of knowledge. Pierre Le Morvan has argued that the New View is untenable, partly because it fails to take into account the distinction between propositional and factive ignorance. I argue that propositional ignorance is just a subspecies of factive ignorance and that all the work that needs to be done can be done by using the concept of factive (...) ignorance. I also defend two arguments of mine in favour of the New View against Le Morvan’s criticisms. As to the Linguistic Argument, I point out that the intuitions of the adherent of the New View about cases of true belief that fall short of knowledge are really intuitions about factive rather than propositional ignorance. As to the Excuse Argument, I argue that true belief is exculpatorily relevant: a true belief in a proposition p , where disbelief that p or suspension on p would provide at least a partial excuse, is relevant in that it renders one blameworthy for one’s action, unless further excuses hold. Finally, I reply to two closely related objections that might be levelled against the New View, namely that it seems false that one can reduce one’s ignorance by arbitrarily believing as many propositions as possible and that it seems false that an intellectually conscientious and critical person is more ignorant than an intellectually sloppy and credulous person just because the latter has more true beliefs. (shrink)

We present and show topological completeness for LB, the logic of the topological border. LB is also a logic of epistemic ignorance. Also, we present and show completeness for LUT, the logic of unknown truths. A simple topological completeness proof for S4 is also presented using a T1 space.