A new experimental method to identify the process of logical reasoning

Abstract: A new method to identify the process of logical reasoning is presented. In spite of its indispensability and importance, we have had few methods to identify a subject's reasoning process, except that of using verbal protocol data. In this paper, for the purpose of objective identification of the reasoning process, we propose a new method to obtain the subject's reasoning process, in terms of a resolution tree for a task of which the logical structure can be written by first-order predicate logic. The results of an experiment using this method are presented. They revealed some interesting features of human reasoning such as, large differences between subjects, remarkable parallel processes, and the existence of subgoals for each subject.     

异同判断中“快同效应”的大脑机制：一项ERP研究

采用高密度的事件相关电位（ERPs）技术,记录分析了大学生被试在执行异同判断任务[包括不同颜色刺激对（DC）,不同形状刺激对（DS）和相同刺激对（Same）]时的脑内时程动态变化。行为结果表明,“同”反应的确显著快于“异”反应,表现出明显的快同效应。ERP结果显示：在280-320 ms内,DS和DC条件均比Same条件诱发一个更负的N2成分。偶极子溯源分析表明,DC和DS条件下,N2可能起源于大脑的前扣带皮层（ACC）,可能与“异”反应早期不一致信息（颜色或形状）的认知监控和调节有关;反之Same条件下,N2成分可能起源于楔前叶,主要反映了“同”反应早期知觉识别中整体特征比较加工的过程（同一性指示器）。另外,在450 ms左右, DC和DS比Same条件均诱发了一个更负的P3成分,可能反映了对刺激局部特征的比较和识别（慢速比较器）,并与选择性注意和资源分配等高级认知活动有关;并且,Same条件下P3成分的潜伏期更短,与行为结果一致。以上研究结果表明,异同判断中“同”反应和“异”反应可能有着不同的比较通道和大脑机制,支持双过程模型理论;同时表明,慢速比较器和同一性指示器可能是序列加工的。     

Products of modal logics and tensor products of modal algebras

One of natural combinations of Kripke complete modal logics is the product, an operation that has been extensively investigated over the last 15 years. In this paper we consider its analogue for arbitrary modal logics: to this end, we use product-like constructions on general frames and modal algebras. This operation was first introduced by Y. Hasimoto in 2000; however, his paper remained unnoticed until recently. In the present paper we quote some important Hasimoto's results, and reconstruct the product operation in an algebraic setting: the Boolean part of the resulting modal algebra is exactly the tensor product of original algebras (regarded as Boolean rings). Also, we propose a filtration technique for Kripke models based on tensor products and obtain some decidability results.     

Conceivability and possibility

We often decide whether a state of affairs is possible (impossible) by trying to mentally depict a scenario (using words, images, etc.) where the state in question obtains (or fails to obtain). These mental acts (broadly thought of as ‘conceiving’) seem to provide us with an epistemic route to the space of possibilities. The problem this raises is whether conceivability judgments provide justification-conferring grounds for the ensuing possibility-claims (call this the ‘conceivability thesis’). Although the question has a long history, contemporary interest in it was, to a large extent, prompted by Kripke's utilization of modal intuitions in the course of propounding certain influential theses in the philosophy of language and mind. The interest has been given a further boost by the recent two-dimensional approach to the Kripkean framework. In this paper, I begin by providing a detailed examination of a most recent attempt (due to Chalmers) to defend the thesis and argue that it is unsuccessful. This is followed by presenting my own gloss on Kripke's explanation of the illusions of contingency and I close by raising a general problem intended to undermine the prospects for a successful defense of the thesis.     

Getting Luck Properly Under Control

This article proposes a new account of luck and how luck impacts attributions of credit for agents' actions. It proposes an analogy with the expected value of a series of wagers and argues that luck is the difference between actual outcomes and expected value. The upshot of the argument is that when considering the interplay of intention, chance, outcomes, skill, and actions, we ought to be more parsimonious in our attributions of credit when exercising a skill and obtaining successful outcomes, and more generous in our attributions of credit when exercising a skill but obtaining unsuccessful outcomes. Furthermore, the article argues that when agents skillfully perform an action, they deserve the same amount of credit whether their action is successful or unsuccessful in achieving the goal.     

What Russell Couldn't Describe

There is currently debate between deflationists and anti-deflationists about the ontology of persisting objects. Some deflationists think that disputes between, for example, four-dimensionalists (e.g. Ted Sider and David Lewis) and quasi-nihilists (e.g. Peter Van Inwagen and Trenton Merricks) are merely verbal disputes. Anti-deflationists deny this. Eli Hirsch is a deflationist who maintains that many ontological disputes are merely verbal. Theodore Sider maintains that the disputes are not merely verbal. Hirsch and Sider are thus engaged in a metaontological dispute. In this paper, I argue that Hirsch's metaontological dispute with Sider is, by Hirsch's own lights, itself merely verbal. I conclude that the mere verbalness of his metaontological dispute with Sider suggests that Hirsch's account of what makes a dispute merely verbal may be problematic.     

A sequent calculus for a logic of contingencies

We introduce a sequent calculus that is sound and complete with respect to propositional contingencies, i.e., formulas which are neither provable nor refutable. Like many other sequent and natural deduction proof systems, this calculus possesses cut elimination and the subformula property and has a simple proof search mechanism.