A Semantic Approach to Conservativity

The aim of this paper is to describe from a semantic perspective the problem of conservativity of classical first-order theories over their intuitionistic counterparts. In particular, we describe a class of formulae for which such conservativity results can be proven in case of any intuitionistic theory T which is complete with respect to a class of T-normal Kripke models. We also prove conservativity results for intuitionistic theories which are closed under the Friedman translation and complete with respect to a class of conversely well-founded Kripke models. The results can be applied to a wide class of intuitionistic theories and can be viewed as generalization of the results obtained by syntactic methods.     

What is the impact of the explicit knowledge of sequence regularities on both deterministic and probabilistic serial reaction time task performance?

The aim of this study was to explore the role of prior explicit sequence knowledge by comparing its influence on serial reaction time (SRT) performance with either a deterministic or a probabilistic sequence. The results confirm that, with a deterministic sequence, preliminary explicit learning improves SRT performance. On the other hand, with a probabilistic sequence, the results show no advantage for SRT performance in explicit-learning conditions. In addition, by using the process dissociation procedure (Jacoby, 1991), we show that performance on a subsequent generation task was more sustained by controlled processes for participants in the explicit-learning conditions than for those in the incidental condition. On the whole, these results, showing that the influence of explicit knowledge can be suppressed in certain specific conditions, are consistent with the intervention of both implicit and explicit mechanisms in SRT tasks, and the results also show that their relative influence can be modulated by the particular demands of the task.     

The SameP-Relation as a Response to Critics of Baker's Theory of Constitution

According to the so-called “standard account” regarding the problem of material constitution, a statue and a lump of clay that makes it up are not identical. The usual objection is that this view yields many objects in the same place at the same time. Lynne Rudder Baker's theory of constitution is a recent and sophisticated version of the standard account. She argues that the aforementioned objection can be answered by defining a relation of being the same P as (sameP). In this paper I shall examine consequences of her response and show that sameP has wrong formal properties, as a result of which this solution cannot be accepted.     

Empty signifiers,education and politics

The paper assumes that education is part of the process of discursive construction of society. The theoretical framework on which this argument is based includes Ernesto Laclau’s theory of the “ontological impossibility and political necessity of society”, and the role discourse and empty signifiers play in the establishment of political identities. Laclau’s theory is supplemented here by ideas of Derrida, Lacan, Žižek and Marx, and by other traits in contemporary semiotics that relate to the notion of “the void” in semantic systems. My claim is that empty signifiers, crucial to the production of the totality of society, are discursively produced, among others, in pedagogical debates. This is illustrated by one historical example (Rouuseau), which gives ground for more contemporary analyses, and on the basis of the present economic discourse of educating and the idea of “knowledge society”. The main conclusion is that education, in contemporary discourse of learning, becomes a neurotic symptom of the lack of overt domination in social relations.

Against a Minimalist Reading of Bell's Theorem: Lessons from Fine

Since the validity of Bell's inequalities implies the existence of joint probabilities for non-commuting observables, there is no universal consensus as to what the violation of these inequalities signifies. While the majority view is that the violation teaches us an important lesson about the possibility of explanations, if not about metaphysical issues, there is also a minimalist position claiming that the violation is to be expected from simple facts about probability theory. This minimalist position is backed by theorems due to A. Fine and I. Pitowsky.Our paper shows that the minimalist position cannot be sustained. To this end,we give a formally rigorous interpretation of joint probabilities in thecombined modal and spatiotemporal framework of `stochastic outcomes inbranching space-time' (SOBST) (Kowalski and Placek, 1999; Placek, 2000). We show in this framework that the claim that there can be no joint probabilities fornon-commuting observables is incorrect. The lesson from Fine's theorem is notthat Bell's inequalities will be violated anyhow, but that an adequate modelfor the Bell/Aspect experiment must not define global joint probabilities. Thus we investigate the class of stochastic hidden variable models, whichprima facie do not define such joint probabilities. The reasonwhy these models fail supports the majority view: Bell's inequalities are notjust a mathematical artifact.     

On decision procedures for sentential logics

In Section 2 I give a criterion of decidability that can be applied to logics (i.e. Tarski consequence operators) without the finite model property. In Section 3 I study ukasiewicz-style refutation procedures as a method of obtaining decidability results.This method also proves to be more general than Harrop's criterion.     

Social class and interpersonal trust: Partner's warmth,external threats and interpretations of trust betrayal

The present research investigated the effects of social class on interpersonal trust. In a series of experiments, we showed how the contextualist socio-cognitive tendencies of the lower class and the solipsistic tendencies of the upper class were reflected in their trusting attitudes and behaviors. In Study 1 (N = 491), upper class individuals expressed the same levels of trust towards all partners, while lower class individuals adjusted their trust choices to the affect-rich information about their interaction partner and trusted warm partners more than cold partners. The results of Study 2 (N = 210) showed that when threatened, lower class individuals had generally less trusting attitudes, while upper class members were equally trusting as in a neutral situation. Study 3 (N = 200) revealed that upper class individuals explained a betrayal of their trust with dispositional factors to a higher degree than lower class individuals. We discuss how these differences contribute to perpetuating the disadvantage of the lower class.