This book celebrates Ole-Jørgen Skog, a great scholar, at his sixtieth birthday. Thematically the essays are as diverse as the interests of the man they honour, but three main themes can be distinguished. The first theme is how to understand choice and explain behaviour. Essays under this heading discuss addiction, weakness of will, discrimination, how criminals solve the problem of trust, the social dependence of preferences, and the relationship between causal, rational and intentional explanations of behaviour. Second, several essays explore the consequences of behaviour, with particular emphasis on the consumption of alcohol, mortality, early onset of drinking and the evolution of social movements. Third, there are philosophical essays on objectivity, ethics, and a conceptual analysis of bullshit. The contributors reflect Ole-Jørgen's wide circle of friends and colleagues, and include many leading scholars. The contributors are: Nobel laureate Thomas C. Schelling, sociologists Raymond Boudon, Diego Gambetta, Peter Hedström, and Trond Petersen, economists George Loewenstein, Hans Olav Melberg, and Karl-Ove Moene, specialised alcohol researchers Griffith Edwards, Thor Nordström, Robin Room, and Ingeborg Rossow, philosophers Olav Gjelsvik and Dagfinn Føllesdal, a political scientist, Raino Malnes, and some who - like Ole-Jørgen himself – defy categorisation: Jon Elster and George Ainslie.