Keep ‘hoping’ for rationality: a solution to the backward induction paradox

We formalise a notion of dynamic rationality in terms of a logic of conditional beliefs on (doxastic) plausibility models. Similarly to other epistemic statements (e.g. negations of Moore sentences and of Muddy Children announcements), dynamic rationality changes its meaning after every act of learning, and it may become true after players learn it is false. Applying this to extensive games, we “simulate” the play of a game as a succession of dynamic updates of the original plausibility model: the epistemic situation when a given node is reached can be thought of as the result of a joint act of learning (via public announcements) that the node is reached. We then use the notion of “stable belief”, i.e. belief that is preserved during the play of the game, in order to give an epistemic condition for backward induction: rationality and common knowledge of stable belief in rationality. This condition is weaker than Aumann’s and compatible with the implicit assumptions (the “epistemic openness of the future”) underlying Stalnaker’s criticism of Aumann’s proof. The “dynamic” nature of our concept of rationality explains why our condition avoids the apparent circularity of the “backward induction paradox”: it is consistent to (continue to) believe in a player’s rationality after updating with his irrationality.     

Generalized Logical Consequence: Making Room for Induction in the Logic of Science

We present a framework that provides a logic for science by generalizing the notion of logical (Tarskian) consequence. This framework will introduce hierarchies of logical consequences, the first level of each of which is identified with deduction. We argue for identification of the second level of the hierarchies with inductive inference. The notion of induction presented here has some resonance with Popper's notion of scientific discovery by refutation. Our framework rests on the assumption of a restricted class of structures in contrast to the permissibility of classical first-order logic. We make a distinction between deductive and inductive inference via the notions of compactness and weak compactness. Connections with the arithmetical hierarchy and formal learning theory are explored. For the latter, we argue against the identification of inductive inference with the notion of learnable in the limit. Several results highlighting desirable properties of these hierarchies of generalized logical consequence are also presented.     

Some Observations on Induction in Predicate Probabilistic Reasoning

We consider the desirability, or otherwise, of various forms of induction in the light of certain principles and inductive methods within predicate uncertain reasoning. Our general conclusion is that there remain conflicts within the area whose resolution will require a deeper understanding of the fundamental relationship between individuals and properties.     

Sensitivity,Induction, and Miracles

Sosa, Pritchard, and Vogel have all argued that there are cases in which one knows something inductively but does not believe it sensitively, and that sensitivity therefore cannot be necessary for knowledge. I defend sensitivity by showing that inductive knowledge is sensitive.     

Emotional processing in psychopathic personality

Emotional‐processing deficits may be one of the characteristic features of impaired affect in individuals with psychopathy. These include shallowness and profound lack of remorse or empathy. Performances on standardized emotion discrimination tasks and mood induction tasks were compared between 17 patients with antisocial personality disorder (DSM‐IV) and 17 nonpsychopaths. Subjects with psychopathic personality demonstrated poorer performance on emotion‐discrimination tasks compared with controls. However, higher scores on factor “emotional detachment” of the Psychopathy Checklist (PCL‐R) were associated with better discrimination ability. Subjective ratings were comparable between groups during mood induction. Although the findings support the hypothesis of a significant association between impaired emotional processing and psychopathy, they also suggest a relationship between emotional discrimination and the core personality features of psychopathy. Aggr. Behav. 28:394–400, 2002. © 2002 Wiley‐Liss, Inc.     

促排卵治疗及其风险的探讨

促排卵药物在临床中的广泛应用,给不孕患者带来了希望,另一方面促排卵带来的风险也越来越引起人们的重视,如卵巢过度刺激综合征(OHSS)、妊娠并发症、出生缺陷和肿瘤等。因此,用哲学的观点客观地看待促排卵的成效与风险之间的关系有助于临床医生进一步提高促排卵安全性的认识,做出正确的决策。     

立体结构特异性逆翻译酶与免疫信号的传递

分子遗传学中心法则提示,遗传信息由蛋白质向ＤＮＡ的输入过程在蛋白质和ＲＮＡ之间是断开的。而获得性特异性免疫反应的产生却意味着机体遇到外来抗原入侵后存在信息增加的过程。本文由此假设：１存在立体结构特异性逆翻译酶,介导信息由蛋白质向ＲＮＡ的传递;２特异性免疫应答形成过程中,逆翻译酶按外来抗原的空间结构合成针对外来抗原的基因片段,是免疫特异性形成的核心