PRELIMINARIES Hysterical trading in art AT THE PRESENT TIME, when a great amount of music is being both composed and heard, a great deal is also being ...

Social dilemmas occur when the pursuit of self-interest by individuals in a group leads to less than optimal collective outcomes for everyone in the group. A critical assumption in the human sciences is that people's choices in such dilemmas are individualistic, selfish, and rational. Hence, cooperation in the support of group welfare will only occur if there are selfish incentives that convert the social dilemma into a nondilemma. In recent years, inclusive fitness theories have lent weight to such traditional views (...) of rational selfishness on Darwinian grounds. To show that cooperation is based on selfish incentives, however, one must provide evidence that people donotcooperatewithoutsuch incentives. In a series of experimental social dilemmas, subjects were instructed to make single, anonymous choices about whether or not to contribute money for a shared “bonus” that would be provided only if enough other people in the group also contributed their money. Noncontributors cited selfish reasons for their choices; contributors did not. If people are allowed to engage in discussion, they will contribute resources at high rates, frequently on irrational grounds, to promote group welfare. These findings are consistent with previous research on ingroup biasing effects that cannot be explained by “economic man” or “selfish gene” theories. An alternative explanation is that sociality was a primary factor shaping the evolution ofHomo sapiens. The cognitive and affective mechanisms underlying such choices evolved under selection pressures on small groups for developing and maintaining group membership and for predicting and controlling the behavior of other group members. This sociality hypothesis organizes previously inexplicable and disparate phenomena in a Darwinian framework and makes novel predictions about human choice. (shrink)

Alphonse Guillebert (1792-1861), pastor, teacher and politician, was one of the leading figures of the Academy of Neuchâtel, founded in 1838 and opened to students in the autumn of 1840. In this article, we will first offer a brief biography, then indications on the various facets of the written work of our author. We have used only a part of the available sources and we are therefore aware that further study would be worthwhile. In the following, we describe the philosophy (...) course of Guillebert, and finally we look at an essay – the Dissertation sur l’unité en philosophie – in which he was more personal than in his teaching. Marked by the French intellectual climate of the first half of the nineteenth century, our author was able, by opening himself to Germany, to introduce his listeners to the main philosophical doctrines of his time. (shrink)

This paper examines the various types of small, portable heliostat which maintain a beam of sunlight in a constant direction. Used mainly in the second half of the nineteenth century, these instruments were intended for optical demonstrations and the illumination of microscopes and similar apparatus, rather than for astronomical applications. Three basic patterns are distinguished: polar heliostats , biaxial single-mirror heliostats, and coelostats. The theory and geometry of each type is explained, followed by a consideration in chronological order of the (...) corresponding working instruments. Heliostats by Fahrenheit, Meyerstein, 's Gravesande, Gambey, Silbermann, Foucault, Stoney and others are illustrated, and extensive references given. (shrink)