he will realize that, while he is gaining apparent efficacy in some superficial part of the mechanism, he is disarranging, dislocating, and disintegrating much more fundamental factors in it. In a word, he is operating, not as a psychologist, but as a poor psychologist, and the only cure for a partial psychology is a fuller one. He is gaining the momentary attention of the child through an appeal to pleasant color, or exciting tone, or agreeable association, but at the expense of isolating one cog and ratchet in the machinery, and making it operate independently of the rest. In theory, it is as possible to demonstrate this to a teacher, showing how the faulty method reacts unhappily into the personality, as it is to locate the points of wrong construction and of ineffective transfer of energy in a physical apparatus. This suggests the admission made by writers, in many respects as far apart as Dr. Harris and Dr. Münsterberg, that scientific psychology is of use on the pathological side, where questions of "physical and mental health" are concerned. But is there anything with which the teacher has concern that is not included in the ideal of physical and mental health? Does health define to us anything less than the teacher's whole end and aim? Where does pathology leave off in the scale and series of vicious aims and defective means? I see no line between the more obvious methods and materials which result in nervous irritation and fatigue, in weakening the power of vision, in establishing spinal curvatures, and others which, in more remote and subtle, but equally real, ways leave the child with, say, a muscular system which is only partially at the service of his ideas, with blocked and inert brain paths between eye and ear, and with a partial and disconnected development of the cerebral paths of visual imagery. What error in instruction is there which could not, with proper psychological theory, be stated in just such terms as these? A wrong method of teaching reading, wrong, I mean, in the full educational and ethical sense, is also a case of pathological use of the psycho-physical mechanism. A method is ethically defective that, while giving the child a glibness in the mechanical facility of reading, leaves him at the mercy of suggestion and chance environment to decide whether he reads the "yellow journal," the trashy novel, or the literature which inspires and makes more valid his whole life. Is it any less certain that this failure on the ethical side is repeated in some lack of adequate growth and connection in the psychical and physiological factors involved? If a knowledge of psychology is important to the teacher in the grosser and more overt cases of mental pathology, is it not even more important in these hidden and indirect matters--just because they are less evident, and more circuitous in their operation and manifestation?