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.     

Horgan on Sleeping Beauty

With the notable exception of David Lewis, most of those writing on the Sleeping Beauty problem have argued that 1/3 is the correct answer. Terence Horgan has provided the clearest account of why, contrary to Lewis, Beauty has evidence against the proposition that the coin comes up heads when she awakens on Monday. In this paper, I argue that Horgan’s proposal fails because it neglects important facts about epistemic probability.     

Evidence for the role of self-priming in epistemic action: expertise and the effective use of memory

Epistemic actions are physical actions people take to simplify internal problem solving rather than to move closer to an external goal. When playing the video game Tetris, for instance, experts routinely rotate falling shapes more than is strictly needed to place the shapes. Maglio and Kirsh [Kirsh, D., & Maglio, P. (1994). On distinguishing epistemic from pragmatic action. Cognitive Science, 18, 513-549; Maglio, P. P. (1995). The computational basis of interactive skill. PhD thesis, University of California, San Diego] proposed that such actions might serve the purpose of priming memory by external means, reducing the need for internal computation (e.g., mental rotation), and resulting in performance improvements that exceed the cost of taking additional actions. The present study tests this priming hypothesis in a set of four experiments. The first three explored precisely the conditions under which priming produces benefits. Results showed that presentation of multiple orientations of a shape led to faster responses than did presentation of a single orientation, and that this effect depended on the interval between preview and test. The fourth explored whether the benefit of seeing shapes in multiple orientations outweighs the cost of taking the extra actions to rotate shapes physically. Benefits were measured using a novel statistical method for mapping reaction-time data onto an estimate of the increase in processing capacity afforded by seeing multiple orientations. Cost was measured using an empirical estimate of time needed to take action in Tetris. Results showed that indeed the increase in internal processing capacity obtained from seeing shapes in multiple orientations outweighed the time to take extra actions.     

Reasons to act and believe: naturalism and rational justification in Hume’s philosophical project

Is Hume a naturalist? Does he regard all or nearly all beliefs and actions as rationally unjustified? In order to settle these questions, it is necessary to examine their key terms (‘naturalism’ and ‘rational justification’) and to understand the character—especially the normative character—of Hume’s philosophical project. This paper argues (i) that Hume is a naturalist—and, in particular, both a moral and an epistemic naturalist—in quite robust ways; and (ii) that Hume can properly regard many actions and beliefs as “rationally justified” in several different senses of that term.     

模糊容忍性与发散性思维的关系：不同认识兴趣的作用

有理论认为,模糊容忍性有助于个体发散性思维的发展,但部分实证研究却呈现出不一致的结论。本文考察了不同认识兴趣在模糊容忍性与发散性思维关系之间的中介和调节作用。结果发现：（1）I型认识兴趣在模糊容忍性和独创性、灵活性、流畅性间起完全中介作用;（2）模糊容忍性与独创性、灵活性的关系受到D型认识兴趣的调节,模糊容忍性与流畅性的关系不受D型认识兴趣的调节。     

Soft Libertarianism and Hard Compatibilism

In this paper I discuss two kinds of attempts to qualify incompatibilist and compatibilist conceptions of freedom to avoid what have been thought to be incredible commitments of these rival accounts. One attempt -- which I call soft libertarianism -- is represented by Robert Kane's work. It hopes to defend an incompatibilist conception of freedom without the apparently difficult metaphysical costs traditionally incurred by these views. On the other hand, in response to what I call the robot objection (that if compatibilism is true, human beings could be the products of design), some compatibilists are tempted to soften their position by placing restrictions on the origins of agency. I argue that both of these attempts are misguided. Hard libertarianism and hard compatibilism are the only theoretical options.     

Common knowledge of payoff uncertainty in games

Using epistemic logic, we provide a non-probabilistic way to formalise payoff uncertainty, that is, statements such as ‘player i has approximate knowledge about the utility functions of player j.’ We show that on the basis of this formalisation common knowledge of payoff uncertainty and rationality (in the sense of excluding weakly dominated strategies, due to Dekel and Fudenberg (1990)) characterises a new solution concept we have called ‘mixed iterated strict weak dominance.’