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 intrinsically require. In the colleges and pre-professional schools we jurists may acquire a little scientific psychology as a ``philosophical propaedeutic,'' but we all know how insufficient it is and how little of it endures in the business of life. And we had rather not reckon up the number of criminalists who, seeing this insufficiency, pursue serious psychological investigations.
One especial psychological discipline which was apparently created for our sake is the psychology of law, the development of which, in Germany, Volkmar recounts. This science afterward developed, through the instrumentality of Metzger and Platner, as criminal psychology. From the medical point of view especially, Choulant's collection of the latter's, ``Quaestiones,'' is still valuable. Criminal psychology was developed further by Hoffbauer, Grohmann,
 W. Volkmann v. Volkmar: Lehrbuch der Psychologie (2 vols.). C
 J. Metzger: ``Gerichtlich-medizinische Abhandhingen.'' K
 Ernst Platner: Questiones medicinae forensic, tr. German by Hederich
 J. C. Hoffbauer Die Psychologie in ibren Hauptanwendungen auf die Rechtspflege. Halle 1823.
 G. A. Grohmann: Ideen zu einer physiognomisehen Anthropologie. Leipzig 1791.
Heinroth, Sehaumann, M