The aim of the book, as the author explains, is to bring before the general public the problems which arise out of attempts to apply psycho-analysis in the field of criminology, 'having regard to the profound social repercussions which might follow if such ideas were to prevail.' (The author's report to the XVIIe Congrès de Médecine Légale de langue française, i.e. to a group of specialists, was confined to the question of the introduction of psycho-analysis in the sphere of legal medicine—see