Ideal Worlds — Wishful Thinking in Deontic Logic

The ideal world semantics of standard deontic logic identifies our obligations with how we would act in an ideal world. However, to act as if one lived in an ideal world is bad moral advice, associated with wishful thinking rather than well-considered moral deliberation. Ideal world semantics gives rise to implausible logical principles, and the metaphysical arguments that have been put forward in its favour turn out to be based on a too limited view of truth-functional representation. It is argued that ideal world semantics should be given up in favour of other, more plausible uses of possible worlds for modelling normative subject-matter.     

Modest deontologism in epistemology

Deontologism in epistemology holds that epistemic justification may be understood in terms of “deontological” sentences about what one ought to believe or is permitted to believe, or what one deserves praise for believing, or in some similar way. If deonotologism is true, and people have justified beliefs, then the deontological sentences can be true. However, some say, these deontological sentences can be true only if people have a kind of freedom or control over their beliefs that they do not in fact have. Thus, deontologism in epistemology, combined with anti-skepticism, has implausible implications. I first describe one sort of control that people typically have over ordinary actions but do not have over typical beliefs. I then argue that there is a paradigmatic type of epistemic evaluation that does properly apply to beliefs even though we lack this sort of control over them. Finally, I argue that these paradigmatic epistemic evaluations are sufficient to make true some of the deontological sentences.     

Haack’s foundherentism is a foundationalism

Susan Haack has always maintained that her unquestionably important foundherentist theory of epistemic justification is not a foundationalism. In a 1997 Synthese exchange, Laurence BonJour questioned her right to this claim, and she dug in and defended it. What was at stake is of timeless importance to epistemology: it goes directly to the question, “What is foundationalism?” I inquire with greater care than either Haack or BonJour took in 1997, and I find decisively in favor of the view that foundherentism is a foundationalism. In the process, I explore the outer limits of foundationalism: I examine just how far a foundationalism can go in allowing the relevance of coherence to epistemic justification.     

Synchronic Bayesian updating and the Sleeping Beauty problem: reply to Pust

I maintain, in defending “thirdism,” that Sleeping Beauty should do Bayesian updating after assigning the “preliminary probability” 1/4 to the statement S: “Today is Tuesday and the coin flip is heads.” (This preliminary probability obtains relative to a specific proper subset I of her available information.) Pust objects that her preliminary probability for S is really zero, because she could not be in an epistemic situation in which S is true. I reply that the impossibility of being in such an epistemic situation is irrelevant, because relative to I, statement S nonetheless has degree of evidential support 1/4.     

Responsibility for believing

Many assume that we can be responsible only what is voluntary. This leads to puzzlement about our responsibility for our beliefs, since beliefs seem not to be voluntary. I argue against the initial assumption, presenting an account of responsibility and of voluntariness according to which, not only is voluntariness not required for responsibility, but the feature which renders an attitude a fundamental object of responsibility (that the attitude embodies one’s take on the world and one’s place in it) also guarantees that it could not be voluntary. It turns out, then, that, for failing to be voluntary, beliefs are a central example of the sort of thing for which we are most fundamentally responsible.     

Persuasive Paradoxes in Cicero's Speeches

The paper first presents a short survey of ancient and modern logical, rhetorical and argumentative approaches (e.g. Aristotle, Quintilian, Quine, Anscombre and Ducrot) studying the properties of paradoxical utterances. This survey is followed by a tentative definition of paradoxes as seemingly contradictory utterances triggering conversational implicatures in the sense of Grice. A specific group of paradoxes, namely, persuasive paradoxes, is further characterized by the specific implicatures which they trigger: the implicatures of persuasive paradoxes serve the interest of the (political) speaker because they either convey a sharp criticism of the political opponent(s) or praise the political activities of the speaker in a highly effective way.The second part of the paper takes a corpus of about 80 paradoxical utterances from Cicero's speeches to show how they are used 1. for a devastating criticism of Cicero's political enemies, 2. a milder form of criticism in the case of his friends, when their political activities have failed, 3. a praise of successful policies of Cicero and his political friends and 4. a defense of unsuccessful activities started by Cicero and his friends.     

An epistemic and dynamic approach to abductive reasoning: Abductive problem and abductive solution

We propose a study of abductive reasoning addressing it as an epistemic process that involves both an agent?s information and the actions that modify this information. More precisely, we present and discuss definitions of an abductive problem and an abductive solution in terms of an agent?s information, that is, in terms of knowledge and beliefs. The discussion is then formalised by ‘implementing’ our definitions in a dynamic epistemic logic framework, where the properties of these definitions are studied, an epistemic action that represents the application of an abductive step is introduced, and an illustrative example is provided. A number of the most interesting properties of abductive reasoning (those highlighted by Peirce) are shown to be better modelled within this approach.     

Inference and update

We look at two fundamental logical processes, often intertwined in planning and problem solving: inference and update. Inference is an internal process with which we uncover what is implicit in the information we already have. Update, on the other hand, is produced by external communication, usually in the form of announcements and in general in the form of observations, giving us information that might not have been available (even implicitly) before. Both processes have received attention from the logic community, usually separately. In this work, we develop a logical language that allows us to describe them together. We present syntax, semantics and a complete axiom system; we discuss similarities and differences with other approaches and mention how the work can be extended.