When Thales was asked what was difficult he said, To know oneself; andwhat was easy, To advise another.Marcus Aurelius counselled, Let another pray, Save Thou my child, butdo 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 selfcontrol may yet accomplish something in the way of fitting us, by taking theedge off our worry, to react more comfortably to our surroundings, thus notonly rendering us more desirable companions, but contributing directly toour own health and happiness.Under the ills produced by faulty mental tendencies I do not include cancerand the like. This inclusion seems to me as subversive of the laws of natureas the cure of such disease by mental treatment would be miraculous. At thesame time, serious disorders surely result from faulty mental tendencies.In this category we must include, for example, hypochondria, a disturbanceshown by undue anxiety concerning ones own physical and mentalcondition.This disorder, with the allied fears resulting from the urgent desireto be always absolutely safe, absolutely well, and absolutely comfortable, iscapable, in extreme cases, of so narrowing the circle of pleasure and ofusefulness that the sufferer might almost as well have organic disease.Neurasthenia (nervous prostration) has for its immediate exciting causesome overwork or stress of circumstance, but the sufferer not infrequentlywas already so far handicapped by regrets for the past, doubts for thepresent, and anxieties for the future, by attention to minute detailsand by unwillingness to delegate responsibilities to others, that he wasexhausted by his own mental travail before commencing upon the overworkwhich precipitated his breakdown. In such cases the occasion of thecollapse may have been his work, but the underlying cause was deeper.Manyneurasthenics who think they are all run down are really all wound up.They carry their stress with them.Among the serious results of faulty mental habit must be included also thedoubting folly (_folie du doute_). The victim of this disorder is soquerulously anxious to make no mistake that he is forever returning to see ifhe has turned out the gas, locked the door, and the like; in extreme cases hefinally doubts the actuality of his own sensations, and so far succumbs tochronic indecision as seriously to handicap his efforts. This condition hasbeen aptly termed a spasm of the attention.The apprehensive and fretful may show, in varying degree, signs of either orall these conditions, according as circumstances may direct their attention.Passing from serious disorders to minor sources of daily discomfort, thereare few individuals so mentally gifted that they are impervious to the distressoccasioned by variations of temperature and of weather; to the annoyancecaused by criticism, neglect, and lack of appreciation on the part of theirassociates; to active resentment, even anger, upon moderate provocation; toloss of temper when exhausted; to embarrassment in unusual situations; tochronic indecision; to the sleeplessness resulting from mental preoccupation;and above all, to the futile regrets, the querulous doubts, and the undueanxiety included under the term worry, designated by a recent author thedisease of the age.