Online research in philosophy

In Rabern and Rabern (2008) we presented a two question solution to 'the hardest logic puzzle ever' (as presented in Boolos (1996)), which relied on self-referential questions. In this note we respond to several worries related to this solution. We clarify our claim that some yes-no questions cannot be answered by the gods and thus that asking such questions of the gods will result in head explosion. We argue that the inclusion of exploding head possibilities is neither cheating nor ad (...) hoc but is instead forced upon us by principles related to Tarski’s theorem. We also respond to concerns that have been raised about our use of self-referential questions in support of the two question solution. In particular, we address the worry that there is a revenge problem lurking, which is analogous to revenge problems that arise for purported solutions to the liar paradox. And we make some further observations about the relationship between self-referential questions, truth- telling gods and the semantic paradoxes. In the appendix we give a two question solution to the modified puzzle (where Random randomly answers 'ja' or da'). (shrink)

The Hardest Logic Puzzle Ever was first described by the late George Boolos in the Spring 1996 issue of the Harvard Review of Philosophy. Although not dissimilar in appearance from many other simpler puzzles involving gods (or tribesmen) who always tell the truth or always lie, this puzzle has several features that make the solution far from trivial. This paper examines the puzzle and describes a simpler solution than that originally proposed by Boolos.

Abstract: I argue that the solution to the Red Hat Problem, a puzzle derived from interactive epistemic logic, requires S5. Interactive epis- temic logic is set out in formal terms, and an attempt to solve the red hat puzzle is made in K, K, and K, each of which fails, showing that a stronger system, K is required.

In this paper, I develop a neglected puzzle for the moral realist. I then canvass some potential responses. Although I endorse one response as the most promising of those I survey, my primary goal is to make vivid how formidable the puzzle is, as opposed to offering a definitive solution.

Harman and Lewis credit Kripke with having formulated a puzzle that seems to show that knowledge entails dogmatism. The puzzle is widely regarded as having been solved. In this paper we argue that this standard solution, in its various versions, addresses only a limited aspect of the puzzle and holds no promise of fully resolving it. Analyzing this failure and the proper rendering of the puzzle, it is suggested that it poses a significant challenge for the defense of epistemic closure.

We examine the paradox of the surprise examination using dynamic epistemic logic. This logic contains means of expressing epistemic facts as well as the effects of learning new facts, and is therefore a natural framework for representing the puzzle. We discuss a number of different interpretations of the puzzle in this context, and show how the failure of principle of success, that states that sentences, when learned, remain to be true and come to be believed, plays a central role in (...) understanding the puzzle. (shrink)

I criticize two accounts of the temporal asymmetry of electromagnetic radiation - that of Huw Price, whose account centrally involves a reinterpretation of Wheeler and Feynman's infinite absorber theory, and that of Dieter Zeh. I then offer some reasons for thinking that the purported puzzle of the arrow of radiation does not present a genuine puzzle in need of a solution.

In this paper, I will argue that Radfords real question is not the conceptual one, as it is usually taken, but the causal one, and show that Waltons account, which treats Radfords puzzle as the conceptual question, is not a satisfactory solution to it. I will also argue that contrary to what Walton claims, the causal question is not only important, but also closely related to the conceptual and normative questions. What matters is not that Walton has not solved Radfords (...) puzzle per se, but that he has not recognized the importance of this puzzle. While doing this, I will suggest a revision to the cognitive theory of emotion. (shrink)

This paper revisits a puzzle that arises for theories of knowledge according to which one can know on the basis of merely inductive grounds. No matter how strong such theories require inductive grounds to be if a belief based on them is to qualify as knowledge, there are certain beliefs (namely, about the outcome of fair lotteries) that are based on even stronger inductive grounds, while, intuitively, they do not qualify as knowledge. This paper discusses what is often regarded as (...) the most promising classical invariantist solution to the puzzle, namely, that beliefs about the outcomes of fair lotteries do not qualify as knowledge because they are too lucky to do so (or, relatedly, because they do not satisfy a safety condition on knowledge), while other beliefs based on potentially weaker inductive grounds are not too lucky (or, relatedly, because they are safe). A case is presented that shows that this solution to the puzzle is actually not viable. It is argued that there is no obvious alternative solution in sight and that therefore the puzzle still awaits a classical invariantist solution. (shrink)