This volume on psychotherapy belongs to a series of books which I am writing to discuss for a wider public the practical applications of modern psychology. The first book, called "On the Witness Stand," studied the relations of scientific psychology to crime and the law courts. This new book deals with the relations of psychology to medicine. Others discussing its relations to education, to social problems, to commerce and industry will follow soon. For popular treatment I divide applied psychology into such various, separated books because they naturally address very different audiences. That which interests the lawyer does not concern the physician, and again the school-teacher has his own sphere of interests. Moreover the different subjects demand a different treatment. The problems of psychology and law were almost entirely neglected.
