HYPOCHONDRIA. A morbid mental condition characterized by undue solicitude regarding the health, and undue attention to matters thereto pertaining. OBSESSION. An unduly insistent and compulsive thought, habit of mind, or tendency to action. DOUBTING FOLLY (_Folie du doute_.) A state of mind characterized by a tendency unduly to question, argue and speculate upon ordinary matters. NEURASTHENIA. A form of nervous disturbance characterized by exhaustion and irritability. PHOBIA. An insistent and engrossing fear without adequate cause, as judged by ordinary standards. OCCUPATION NEUROSIS. A nervous disorder in which pain, sometimes with weakness and cramp, results from continued use of a part. PSYCHO-THERAPY. Treatment through the mind. No other technical terms are used. I. INTRODUCTORY When Thales was asked what was difficult he said, "To know oneself"; and what was easy, "To advise another." Marcus Aurelius counselled, "Let another pray, 'Save Thou my child,' but do thou pray, 'Let me not fear to lose him.'" Few of us are likely to attain this level; few, perhaps, aspire to do so. Nevertheless, the training which falls short of producing complete self-control may yet accomplish something in the way of fitting us, by taking the edge off our worry, to react more comfortably to our surroundings, thus not only rendering us more desirable companions, but contributing directly to our own health and happiness. Under the ills produced by faulty mental tendencies I do not include cancer and the like. This inclusion seems to me as subversive of the laws of nature as the cure of such disease by mental treatment would be miraculous. At the same time, serious disorders surely result from faulty mental tendencies. In this category we must include, for example, hypochondria, a disturbance shown by undue anxiety concerning one's own physical and mental condition. This disorder, with the allied fears resulting from the urgent desire to be always absolutely safe, absolutely well, and absolutely comfortable, is capable, in extreme cases, of so narrowing the circle of pleasure and of usefulness that the sufferer might almost as well have organic disease. Neurasthenia (nervous prostration) has for its immediate exciting cause some overwork or stress of circumstance, but the sufferer not infrequently was already so far handicapped by regrets for the past, doubts for the present, and anxieties for the future, by attention to minute details and by unwillingness to delegate responsibilities to others, that he was exhausted by his own mental travail before commencing upon the overwork which precipitated his breakdown. In such cases the occasion of the collapse may have been his work, but the underlying cause was deeper. Many neurasthenics who think they are "all run down" are really "all wound up." They carry their stress with them.