Anorexia nervosa is currently classed as a mental disorder. It is considered as a puzzling condition, scarcely understood and recalcitrant to treatment. This paper reviews the main hypotheses relating to the aetiology of anorexia nervosa. In particular, it focuses on family and sociological studies of anorexia. By reflecting on the hypotheses provided within these domains, and on the questions that these studies leave unanswered, this paper suggests that anorexic behaviour is understandable and rational, if seen in light of ordinary moral (...) values. (shrink)