The first method to bring back the psychophysical equilibrium is of course the one which is also demanded by common-sense, namely, to remove the external sources of the disturbance. External indicates there not only the outer world but also the own body outside the conscious parts of the brain. If we take it in the widest meaning, this would evidently include every possible medical task from filling a painful tooth to operating on a painful appendix, as in every case where pain results, the mental equilibrium is disturbed by it and the normal mental life of the patient reduced in its efficiency. But in the narrower sense of the word, we shall rather think of those sources of trouble in the organism itself which interfere directly with the mental functions. The examination of any public school quickly leads to the discovery that much which is taken for impaired mental activity, for lack of attention, for stupidity, or laziness may be the result of defective hearing or sight or abnormal growth of the adenoids. Growths in the nose may be operated upon, the astigmatic or the short-sighted eye may be corrected by glasses, the child who is hard of hearing may at least be seated near the teacher; and the backward children quickly reach the average level. No doubt in the life of the adult as well, often almost insignificant and from a strictly physical point of view unimportant abnormities in the bodily system, especially in the digestive and sexual spheres, are sources of irritation which slowly influence the whole personality. To be sure, the brain disturbance may have reached a point where the mere removal of the original affliction is not sufficient to reinstate the normal balance of mental energies, but wherever such a bodily irritation goes on, it is never too late to abolish it in the interests of psychotherapy.