The control of the colonic motor function, and especially of the series of events which lead to defecation, is generally recognized as being a subject of the greatest importance in medicine; and, more particularly, the possibilities of varying that control. There are a large number of diseases that may, in special instances or in general, be due to constipation and inefficient elimination of waste products. Constipation has been claimed as the first step towards the different catastrophes ranging from Menière's disease and otosclerosis, gout, hyperpiesia and certain of the rheumatisms, to cases of hernia and abnormal presentation. It is my endeavour to look upon it as being even more prominently a secondary manifestation, a symptom of an even more widespread condition—mental misapplication and disorders of mental forces. With this in mind and dealing with an argument that is already proved to some degree in its most marked details, it is hoped to present, not masses of data and deduction so much as an illustration of the value, and even a hint at the frequent therapeutic necessity of orientating the various causation circles in this direction. As a cause, and especially of these mental difficulties themselves, constipation is well enough stressed; constipation as a result has not yet been sufficiently realized, nor attacked rationally from its base. The words “habit formation” cover most of the therapeutic efforts from the mental side, and that is conceived very much as a time-conditional reflex of purely physical determination. A more definite idea, then, of the mental aspect of intestinal motor function may be helpful, and especially so when so many of the habitual purgative class of drug are being authoritatively questioned as being disorganizing to this proper function. The treatment of constipation is hardly yet on a successful or rational basis.