No Future

The difficulties with formalizing the intensional notions necessity, knowability and omniscience, and rational belief are well-known. If these notions are formalized as predicates applying to (codes of) sentences, then from apparently weak and uncontroversial logical principles governing these notions, outright contradictions can be derived. Tense logic is one of the best understood and most extensively developed branches of intensional logic. In tense logic, the temporal notions future and past are formalized as sentential operators rather than as predicates. The question therefore arises whether the notions that are investigated in tense logic can be consistently formalized as predicates. In this paper it is shown that the answer to this question is negative. The logical treatment of the notions of future and past as predicates gives rise to paradoxes due the specific interplay between both notions. For this reason, the tense paradoxes that will be presented are not identical to the paradoxes referred to above.     

Sharvy’s Lucy and Benjamin Puzzle

Sharvy’s puzzle concerns a situation in which common knowledge of two parties is obtained by repeated observation each of the other, no fixed point being reached in finite time. Can a fixed point be reached?     

Naming and Diagonalization, from Cantor to Godel to Kleene

We trace self-reference phenomena to the possibility of namingfunctions by names that belong to the domain over which thefunctions are defined. A naming system is a structure of theform (D, type( ),{ }), where D is a non-empty set; for everya D, which is a name of a k-ary function, {a}: D^k D is thefunction named by a, and type(a) is the type of a, which tellsus if a is a name and, if it is, the arity of the named function.Under quite general conditions we get a fixed point theorem,whose special cases include the fixed point theorem underlyingGödel's proof, Kleene's recursion theorem and many othertheorems of this nature, including the solution to simultaneousfixed point equations. Partial functions are accommodated byincluding "undefined" values; we investigate different systemsarising out of different ways of dealing with them. Many-sortednaming systems are suggested as a natural approach to generalcomputatability with many data types over arbitrary structures.The first part of the paper is a historical reconstruction ofthe way Gödel probably derived his proof from Cantor'sdiagonalization, through the semantic version of Richard. Theincompleteness proof–including the fixed point construction–resultfrom a natural line of thought, thereby dispelling the appearanceof a "magic trick". The analysis goes on to show how Kleene'srecursion theorem is obtained along the same lines.     

Can Deflationists be Dialetheists?

Philosophical work on truth covers two streams of inquiry, one concerning the nature (if any) of truth, the other concerning truth-related paradox, especially the Liar. For the most part these streams have proceeded fairly independently of each other. In his Deflationary Truth and the Liar (JPL 28:455–488, 1999) Keith Simmons argues that the two streams bear on one another in an important way; specifically, the Liar poses a greater problem for deflationary conceptions of truth than it does for inflationist conceptions. We agree with Simmons on this point; however, we disagree with his main conclusion. In a nutshell, Simmons' main conclusion is that deflationists can solve the Liar only by compromising deflationism. If Simmons is right, then deflationists cannot solve the Liar paradox. In this paper we argue that, pace Simmons, there is an approach to the Liar that is available to deflationists, namely dialetheism.     

The adaptation of non‐western and Muslim immigrant adolescents in the Netherlands: An immigrant paradox?

van Geel, M. & Vedder, P. (2010). The adaptation of non‐western and Muslim immigrant adolescents in the Netherlands: An immigrant paradox? Scandinavian Journal of Psychology, 51, 398–402. This article addresses the possible existence of an immigrant paradox in a sample of immigrant adolescents attending vocational schools in the Netherlands. An immigrant paradox is the finding that first generation immigrants show a more positive pattern of adaptation than nationals despite poorer economic conditions. Second generation immigrants regress to the nationals in terms of adaptation. A sample of 152 first generation immigrant adolescents, 285 second generation immigrant adolescents and 406 national adolescents completed self‐reports about socio‐economic status, psychological problems, behavioral problems and self‐esteem. The results supported the existence of an immigrant paradox in this sample. This indicates that further assimilation among immigrant adolescents does not necessarily lead to increased well being.     

追求积极情绪可能导致消极后果及其机制探讨

近年来有关研究发现了追求积极情绪可能给个体带来消极后果, 即个体越追求积极情绪, 他们很可能越体验不到幸福, 并称之为“追求积极情绪的悖论”。当个体把追求积极情绪作为目标时, 可能会(1)为个人的快乐设定过高的标准; (2)通过不恰当的活动去获得快乐; (3)监控获得快乐的过程, 妨碍了沉浸体验。这三个心理过程导致了“追求积极情绪的悖论”。未来的研究应该进一步关注：(1)全面揭示追求积极情绪的后果; (2)揭示追求积极情绪导致消极后果的生理神经机制; (3)追求积极情绪的跨文化研究; (4)探索正确追求积极情绪的方式。     

班级环境如何影响受欺负者的适应？健康环境悖论及其发生机制

“健康环境悖论”是指在受欺负水平相对较低的环境中,受欺负个体有更多的适应问题。通过梳理相关实证研究,本文从人际与认知两大方面分析健康环境悖论的发生机制。人际机制强调健康环境会影响同伴群体对于受欺负者的态度和受欺负者的友谊,这些不良的人际关系进一步加剧受欺负者的适应困难。认知机制认为健康环境会通过向上的社会比较和消极归因方式,影响受欺负者的适应问题。最后,我们讨论了中国文化背景下“健康环境悖论”的适用性问题、未来研究的发展方向和对于干预实践的建议。     

心理咨询的价值悖论与责任伦理

从责任伦理角度审视心理咨询中的价值问题,价值是一个不可悬置也不可逃避的问题。一方面,人的生存悖论与人的社会化过程失衡是人的心理失衡或心理疾病产生的主要原因;另一方面,心理咨询的宗旨是促进来访者的改变,这种改变往往意味着价值观的改变。因而改变过程中必然会出现文化及规范、咨询者价值取向及来访者已有的价值观三者间的冲突和矛盾。心理咨询中的价值之争实为价值冲突所致。对心理咨询中的价值问题的处理应该遵循普遍性原则,采取多种形式的价值介入。     

Diamonds are a Philosopher's Best Friends

The knowability paradox is an instance of a remarkable reasoning pattern (actually, a pair of such patterns), in the course of which an occurrence of the possibility operator, the diamond, disappears. In the present paper, it is pointed out how the unwanted disappearance of the diamond may be escaped. The emphasis is not laid on a discussion of the contentious premise of the knowability paradox, namely that all truths are possibly known, but on how from this assumption the conclusion is derived that all truths are, in fact, known. Nevertheless, the solution offered is in the spirit of the constructivist attitude usually maintained by defenders of the anti-realist premise. In order to avoid the paradoxical reasoning, a paraconsistent constructive relevant modal epistemic logic with strong negation is defined semantically. The system is axiomatized and shown to be complete.