Although lately the necessity of psychiatric knowledge for the pedagogue has been insisted upon in professional circles, for instance, by Professor STRUEMPELL in his _Pedagogic Pathology_ (comp. _The Monist_ II, 106), yet instruction in this department occupies a wholly subsidiary place in pedagogic education, and has not been made as it should have been, an organic part of the same. The writer of these lines has accordingly discussed this subject in a special treatise, maintaining that the most important diseased phenomena of mental life might be treated as a part of pedagogic psychology (comp. _The Monist_ I, 619). The demands made were met in different ways. While the English and American press accepted these demands without reserve (for instance, in HALL’S _Pedagogical Seminary_, I, 297), in Germany there has been more caution displayed, inasmuch as the opposing difficulties were regarded as greater than they probably were (Professor REIN’S _Pädagogische Studien_, 1892, Heft I). We have, however, simply to call to mind the doctrine which more than twenty years ago Maudsley in his “Physiology and Pathology of the Mind” laid such special emphasis upon, that psychic laws are the same in healthy and diseased phenomena, only that they do not operate under the same conditions and therefore produce different symptoms. Far from its being true, therefore, that the introduction of psychopathology into psychology can be opposed by any especially well-founded objections, such a procedure will, on the contrary, be found to be, just as Maudsley said, an appropriate and absolutely indispensable auxiliary of the study of this science. And that which was emphasised by Maudsley, and lately also by MUENSTERBERG in the treatise already discussed in _The Monist_ (II, 289), _On the Problems and Methods of Psychology_ (Leipsic, 1891, Abel), Ziehen has done in his “Outlines of Physiological Psychology” in a manner which will be full of suggestions for the pedagogue (comp. _The Monist_ I, 598).