The author tells us that this book is a “manual” for judges, practitioners and students; for it deals not only with the psychology of criminals or suspected criminals, but with that of judges, magistrates, witnesses and police also. To every thoughtful layman I would heartily recommend this book, for it is well worth reading and pondering; but I would rigidly prevent all judges, magistrates and jurymen having access to it. Why? Because it is their business and prerogative to decide upon the guilt or innocence of the prisoner according to the weight of the evidence, every detail of which demands their concentrated attention if justice is to be done.
I can imagine nothing more disastrous to the administration of justice than a course of study of what is called criminal psychology. Students of human nature I would have them all to be, for such study is essential and leads to nothing but good. But to issue “manuals” that profess to instruct them upon the mysterious working of the human mind; to teach them to weigh the relative worth of provincial mannerism and individual characteristics; to tell the value of a look of the eyes, the smile of the face, and the movement of the hands; to teach them to notice all these things, and then by a process of inductive reasoning to decide upon the guilt or innocence of the individual may be criminal psychology, but it is rubbish none the less, and dangerous rubbish too!
Do the eminent writers of these books ever consider the effect likely to be produced on the minds of judges, magistrates and jurors who may read, believe and adopt their teaching?
Humbly, but very earnestly, I say that any magistrate, judge or juror who is steeped in this kind of teaching is quite unfitted by his supposed knowledge for the task he has in hand. For of all men, judges require the open mind and the clean slate and with them there must be no judgment formed apart from the evidence of fact. They of all men must not be inflated with the idea that they can “read people”—can see through them; that they, independently of evidence, can give a correct judgment.
Let us suppose that we compelled our magistrates, great and small, to pass an examination in criminal psychology, using these “manuals” as textbooks. I venture to say that a queer state of things would follow. The action of magistrates would be dominated by their own individual psychology, and their own psychology would be dominated by the effect the “manual” had produced on their mind. The shallow man would be assured of his competence and knowledge, and he would, to his own satisfaction at least, know all about it. But the greater man would hesitate; he would be in a quandary, on the horns of a dilemma, for he would find that the formula of his “manual,” by which he was to form an opinion as to the guilt of the prisoner, applied with equal force to the innocence of the prisoner.