The truth is, once a tic is established, it has all the appearance of an involuntary movement, but that nevertheless its manifestations may be either modified or inhibited by an effort of the will is patent from clinical observation. This is a fact of great importance. Spasm knows no control (says Brissaud). Nothing will arrest the bolus of food as it passes into the pharynx, unless by the inversion of the whole function of deglutition.... As regards tic, however, inhibition is possible because the phenomenon is cortical. In almost every case, reinforcement of the will can momentarily at least check it. Consensus of opinion admits diminution of will power to be the cardinal mental symptom of the tic patient. Inhibitory insufficiency, as Blocq and Onanoff say, allows the persistence of fixed ideas of movement which reveal themselves by involuntary acts. Noir has admirably supplemented the researches of Ribot in this direction: The infant's activity is purely reflex, and manifested by a profusion of movements, to suppress or restrain the majority of which is the task of education. It is highly probable that any co-ordinated tic whose evolution can be traced at all has its origin in the infant's spontaneous muscular play. From this point of view the frequency of these movements in idiots is readily explicable, since their intellectual development never gets beyond the stage of childhood. The more confirmed the idiocy and the more rudimentary their mind, the more prone are their tics to be complex and inveterate. These remarks are pertinent to the case not only of idiots, imbeciles, or backward children, but of all the subjects of tic. In them some degree of mental infantilism is of invariable occurrence. The tic patient has the weak and capricious will of the child; young or old, he does not know how to _will_; if his willing be sometimes excessive, it is never resolute. Were it otherwise, he might control his meaningless gestures, but his efforts are both feeble and ephemeral. TIC AND HABIT The view which regards tic as a "pathological muscular habit" provides emphatic illustration of the sinister influence of volitional infirmity.