OF all disciplines necessary to the criminal justice in addition to the knowledge of law, the most important are those derived from psychology. For such sciences teach him to know the type of man it is his business to deal with. Now psychological sciences appear in various forms. There is a native psychology, a keenness of vision given in the march of experience, to a few fortunate persons, who see rightly without having learned the laws which determine the course of events, or without being even conscious of them. Of this native psychological power many men show traces, but very few indeed are possessed of as much as criminalists.
