Desire & Impulse
Desire is an impulse: it seizes you, you know, it clings to you, holds you. And then, if you let desire do what it likes, well, it makes you do anything at all, and it makes use of your will. But usually, a desire is something violent, passionate and transient. Rarely is it very sustained; it does not have the stuff, the organisation of a sustained effort. When a desire seizes you, it can make you do anything whatever—but impulsively, not methodically.