When an appetite is in accord with those habits of an individual which enable him to perform his social functions, or which naturally accrue from his social relations, it is legitimate and good; when it conflicts, it is illicit, it is lust; we call it by hard names and we demand that it be curbed; we regard its force as a menace to the integrity of the agent and a threat to social order. When the reflective habits of an individual come into conflict with natural appetites and impulses, the manifestation of which would enlarge or make more certain the powers of the individual in his full relations to others, it is the reflective habits which have to be held in and redirected at the cost of whatever disagreeableness. =(2) The Authority of Duty.=--A duty, in Kant's words, is a _categorical_ imperative--it claims the absolute right of way as against immediate inclination. That which, on one side, is the constraint of natural desire, is, on the other, the authoritative claim of the right end to regulate. Over against the course of action most immediately urgent, most easy and comfortable, so congenial as at once to motivate action unless checked, stands another course, representing a wider and more far-reaching point of view, and hence furnishing the rational end of the situation. However lacking in intensity, however austere this end, it stands for the whole self, and is therefore felt to be rightly supreme over any partial tendency. But since it looks to realization in an uncertain future, rather than permission just to let go what is most urgent at the moment, it requires effort, hard work, work of attention more or less repulsive and uncongenial. Hence that sense of stress and strain, of being pulled one way by inclination and another by the claims of right, so characteristic of an experience of obligation.