Similarity semantics and minimal changes of belief

Different similarity relations on sets are introduced, and their logical properties are investigated. Close relationships are shown to hold between similarity relations that are based on symmetrical difference and operators of belief contraction that are based on relational selection functions. Two new rationality criteria for minimal belief contraction, the maximizing property and the reducing property, are proposed.     

Sexual Debut Ages in Heterosexual,Lesbian, Gay,and Bisexual Young Adults in Norway

This study estimates sexual debut ages in young heterosexual, lesbian, gay, and bisexual men and women in Norway. A questionnaire survey was completed online by 27.2 % of a representative national web sample of 2090 persons aged 18–29 years. Three self-selected samples of 924 respondents completed an extended version of the survey online. Lesbian and bisexual women reported earlier experience of orgasm through masturbation than heterosexual women (median 13.1 vs. 15.2 years), and heterosexual men (median 13.5) reported earlier debut than heterosexual women. There was a statistically significant difference between heterosexual and lesbian and bisexual women’s age at the first experience of receptive vaginal sex (median 16.8 vs. 15.4 years). As regards experience of insertive vaginal sex, a significantly higher percentage of heterosexual men than women, and of heterosexual and lesbian and bisexual women, reported experience. It was more common among lesbian and bisexual women than heterosexual women to have had oral sex with another woman, but in neither group did the cumulative percent reach 50 % by the age of 29 years and the median could not be estimated. Gay and bisexual men reported earlier receptive anal sex debut than heterosexual men. With regard to insertive anal sex, gay and bisexual men accumulated experience earlier than heterosexual men, and lesbian and bisexual women acquired this experience earlier than heterosexual women. Compared to heterosexuals, LGB persons of both genders engage in more varied sexual activities. Lesbian and gay persons have same-sex experiences at an earlier age than bisexuals.     

Health‐adjusted neuropsychological test norms based on 463 older Swedish car drivers

There is a need for improved normative information in particular for older persons. The present study provides neuropsychological test norms on seven cognitive tests used in a sample representing the general older driving population, when uncontrolled and controlled for physical health. A group of 463 healthy Swedish car drivers, aged 65 to 84 years, participated in a medical and neuropsychological examination. The latter included tests of visual scanning, mental shifting, visual spatial function, memory, reaction time, selective attention, and simultaneous capacity. Hierarchical regression analyses demonstrated that, when uncontrolled for health, old age was associated with significant impairment on all seven tests. Education was associated with a significant advantage for all tests except most reaction time subtests. Women outperformed men on selective attention. Controlling for health did not consistently change the associations with education, but generally weakened those with age, indicating rises in normative scores of up to 0.36 SD (residual). In terms of variance explained, impaired health predicted on average 2.5%, age 2.9%, education 2.1% and gender 0.1%. It was concluded (1) that individual regression‐based predictions of expected values have the advantage of allowing control for the impact of health on normative scores in addition to the adjustment for various demographic and performance‐related variables and (2) that health‐adjusted norms have the potential to classify functional status more accurately, to the extent that these norms diverge from norms uncontrolled for physical health.     

Specified Meet Contraction

Specified meet contraction is the operation ?\div defined by the identity K ?p = K   ~  f(p)K \div p = K \,{\sim}\, f(p) where ∼ is full meet contraction and f is a sentential selector, a function from sentences to sentences. With suitable conditions on the sentential selector, specified meet contraction coincides with the partial meet contractions that yield a finite-based contraction outcome if the original belief set is finite-based. In terms of cognitive realism, specified meet contraction has an advantage over partial meet contraction in that the selection mechanism operates on sentences rather than on temporary infinite structures (remainders) that are cognitively inaccessible. Specified meet contraction provides a versatile framework in which other types of contraction, such as severe withdrawal and base-generated contraction, can be expressed with suitably chosen properties of the sentential selector.     

Cutting the Gordian Knot of Demarcation

A definition of pseudoscience is proposed, according to which a statement is pseudoscientific if and only if it (1) pertains to an issue within the domains of science, (2) is not epistemically warranted, and (3) is part of a doctrine whose major proponents try to create the impression that it is epistemically warranted. This approach has the advantage of separating the definition of pseudoscience from the justification of the claim that science represents the most epistemically warranted statements. The definition is used to explain why proponents of widely divergent criteria for the demarcation between science and pseudoscience tend to be in almost complete agreement on the particular demarcations that should presumably be based on these general criteria.     

A Survey of non-Prioritized Belief Revision

This paper summarizes and systematizes recent and ongoing work on non-prioritized belief change, i.e., belief revision in which the new information has no special priority due to its novelty.     

In defense of base contraction

In the most common approaches to belief dynamics, states of belief are represented by sets that are closed under logical consequence. In an alternative approach, they are represented by non-closed belief bases. This representation has attractive properties not shared by closed representations. Most importantly, it can account for repeated belief changes that have not yet been satisfactorily accounted for in the closed approach.     

Decision theoretic foundations for axioms of rational preference

Rationality postulates for preferences are developed from two basic decision theoretic principles, namely: (1) the logic of preference is determined by paradigmatic cases in which preferences are choice-guiding, and (2) excessive comparison costs should be avoided. It is shown how the logical requirements on preferences depend on the structure of comparison costs. The preference postulates necessary for choice guidance in a single decision problem are much weaker than completeness and transitivity. Stronger postulates, such as completeness and transitivity, can be derived under the further assumption that the original preference relation should also be capable of guiding choice after any restriction of the original set of alternatives.     

Die Geisteswissenschaften und die Praxis

Ohne ZusammenfassungDer vorliegende Beitrag stellt die auf das Dreifache erweiterte Fassung eines Vortrags dar, den ich unter dem Titel Zur Funktion der Geisteswissenschaften in der Konzeption von J. Habermas auf dem XI. Deutschen Kongress für Philosophie (Oktober 1975) in Göttingen gehalten habe.