I.—Until quite modern times the expression ‘Criminal Science’ was taken to mean no more than study of criminal law. The nature and the method of criminal science at this stage is best illustrated by the well-known dictum of Carrara, one of the chief exponents of the classical school of criminal law, that ‘crime is not an entity in fact but an entity in law; it is not action but infraction’ (‘il delitto non è un ente di fatto ma un ente giuridico, è una infrazione e non un’azione’). The personality of the delinquent, the origin of crime, the nature and the efficacy of punishment, the relationship between society and criminal justice,—problems which now constitute such an important part of criminal research—for many decades remained completely outside the scope of criminal science as then understood.