When the instinct of fear is aroused in connection with some future impending misfortune, the feeling of apprehension with all its physiological changes, muscular, respiratory, cardiac, epigastric, and intestinal, goes to form that complex feeling of anxiety so highly characteristic of the acute varieties of psychopathic maladies. When fear reaches its acme, the heart is specially affected; circulatory and respiratory changes become prominent, giving rise to that form of oppression which weighs like an incubus on the patient,--the feeling known as “precordial anxiety.” The fear instinct is the ultimate cause of functional psychosis,--it is the soil on which grow luxuriantly the infinite varieties of psychopathic disturbances. The body, sense, intellect, and will are all profoundly affected by the irresistible sweep of the fear instinct, as manifested in the overwhelming feeling of anxiety. The fear instinct and its offsprings--hesitation, anxiety, conflicts and repressions--weaken, dissociate, and paralyze the functions of the body and mind, producing the various symptoms of psychopathic diseases. The fear instinct keeps on gnawing at the very vitals of the psychopathic patient. Even at his best the psychopathic patient is not free from the workings of the fear instinct, from the feeling of anxiety which, as the patients themselves put it, “hangs like a cloud on the margin or fringe of consciousness.” From time to time he can hear the distant, threatening rumbling of the fear instinct. Even when the latter is apparently stilled, the pangs of anxiety torment the patient like a dull toothache. Montaigne, writing of fear, says, “I am not so good a naturalist (as they call it) as to discern by what secret springs fear has its motion in us; but be this as it may, it is a strange passion, and such a one as the physicians say there is no other whatever that sooner dethrones our judgment from its proper seat; which is so true, that I myself have seen very many become frantic through fear; and even in those of the best settled temper, it is most certain that it begets a terrible confusion during the fit. Even among soldiers, a sort of men over whom, of all others, it ought to have the least power, how often has it converted flocks of sheep into armed squadrons, reeds and bullrushes into pikes and lances, and friends into enemies....