This book is a sign of its times. Each one of the chapters - papers written by European authors of various backgrounds- illustrates a departure from the style of theorizing that has been prominent in the behavioral and social sciences for most of the century. Until very recently, models for behavioral phenomena were chi fly based on numerical representations of the objects of concern, e. g. the subjects and the stimuli under study. This was due in large part to the influence of nineteenth century physics, which played the role of the successful older sister, the one that had to be imitated if...