Title: Norminterpretation und ökonomische Analyse des Rechts
Author: Christian Kirchner / Stefan Koch
Page: 111-133

Abstract: Normative economics and a hermeneutic approach to interpretation of legal norms are only compatible if - and this is the exception - such legal norms have the goal of accomplishing economic efficiency. But economic analysis of law as a positive approach may be used in the legal interpretation process in order to evaluate different options of norm inter-pretations. In fields of law where economic issues are at stake such a methodological evaluation of interpretative variants are superior to common sense analysis and should be applied. But even in fields where non-economic issues play a major role an economic analysis is a helpful tool in order to get aware of the opportunity costs of economically sub-optimal solutions. Economic analysis of law thus becomes an integral part of the norm interpretation process without colliding with the autonomy of the legal decision enhancing the rationality of the endeavour.

Title: Kooperative Strategien im Gefangenendilemma. Computersimulation eines N-Personen-Spiels
Author: Andreas Diekmann / Klaus Manhart
Page: 134-153

Abstract: Simulation studies in the context of Robert Axelrod's research on iterative prisoner's dilemma games focus nearly exclusively on the two-player-version of the game. In contrast, this article reports results of a simulation with an iterated N-prisoners, dilemma where group size N varies between 2 and 30. The simulation investigates the relative performance of conditional cooperative strategies with increasing group size. Results show that some 'nice' strategies like 'tit-for-tat' are relatively successful and robust even in larger groups and non-nice environments. However, this does not solve the cooperation problem. On the contrary, the relative success of some 'nice' conditional cooperative strategies is paralleled by a rapid decline of cooperation in large groups.

Title: Das Verhältnis von Moral und Rationalität. Eine Auseinandersetzung mit David Gauthiers Morals by Agreement
Author: Jean-Louis Arni
Page: 154-178

Abstract: The relation between morality and rationality (in the sense of rational choice and rational behaviour) is a prominent theme in (the tradition of) moral philosophy. D. Gauthier's account of this relation is an extraordinarily impressive one. He attempts to demonstrate a general co-incidence (at different levels) between rationality and morality. His approach is discussed in what follows, and it will be shown that most of his 'coincidence claims' are exaggerated.

Title: Kollektive Güter und individuelle Verantwortung
Author: Anton Leist
Page: 179-196

Abstract: In acting within large groups the single actor typically suffers from the symptom of irrelevance of his contribution. A single contributory effect may be extremely small or, due to 'threshold effects', even non-existent. Given such conditions not only self-interested action, also purely altruistically motivated contribution seems to be rendered irrational. The article reasons that the famous 'principles of generalization' are of no help on this problem. However, a 'principle of division' could be used in show-ing that in many situations of collective action altruistically motivated contribution is rationally sound.

Title: What Does Doing One's Part of a Joint Action Involve?
Author: Raimo Tuomela
Page: 197-207

Abstract: The paper gives a conceptual clarification of what the notion of apart of a joint action (project, etc.) involves. The - mutually re-cognized - division of a joint action into parts can be based on social norms (viz. formal or informal rules, or proper social norms such as conventions or group specific social norms) or it can be based on agreement, coercion, or some analogous social mechanism. The paper also discusses the notions of a we-intention, of the intention to perform an action as one's part of a joint action, and of an agent's intentionally performing an action as his part of a joint action.