Pain from restriction or intermission of some organic activity, as the digestive and assimilatory, may then lead to sense of lack and desire for object which is unrealized. However, craving-desire as implying sense of loss, of something pleasurable missed, is not organic, but is mere reflex of organization. It is not progressive, but conservative; it does not initiate, it merely keeps the organism to its accustomed level. This is the limited range of appetite. Craving rests on past evolution. However, we have to explain the origin of those activities which, when intermitted, produce such distressful results. We must first acquire the liking before we miss what we like, and tastes uniformly originate through effort, and all pleasurable activity is built up by painful volition as urged by direct pains or by desires. Desire then is more than craving. Craving as based on organic lack is satiable, desire is insatiable. We desire what we have never missed and modes of experience we have never attained. We, who have never had a gold watch, desire one, and having received one, we lose it, miss it, and so desire is reinforced. All the progressive activity of the human world originates in desire, as ambition, or as desire of truth, virtue, etc. Here we do not miss what we are accustomed to, but we are forming habits, which will be the basis for cravings with descendants. For instance, one who now does not miss beauty of art, but is ambitiously striving to appreciate art, may come finally—or at least his descendants—to miss art, and so to crave it. But for the time he has no art craving, only an art desire. Of course all desire in the craving form, or in the higher desire form, involves a missing actualization. All desire is extinguished in realization. But this obviously does not destroy the distinction of desire as based on craving, a spontaneous resultant from integration, an intermittence of habit, and desire as itself integrating habit-forming emotion.