Desire is _at_ pleasure, not _in_ pleasure, and thus contains pain, especially as implied in the preparative factors, sense of unreality and sense of lack. A bonbon may be so cunningly imitated, that placed in the mouth it feels like a bonbon, yet not tasting so, the painful sense of unreality and loss occurs. There is a painful waking up to the fact of non-realization, much the same in quality as that which we suppose to have happened in the original genesis of desire. The pleasant hallucination is broken in upon by actuality not fulfilling the psychic co-ordination pre-established under more favourable circumstances; and this occurs in early psychisms on a wider variety of occasions than in later development. That I am not tasting the bonbon I see on the table, this fact _per se_ does not pain me. I take it as a matter of course in an order of nature already well learned and completely acquiesced in. But with infantile and lower stages of evolution generally, the lack of immediate correlation seems highly painful. Seeing has directly developed in immediate connection with a tasting, and the seeing without tasting seems by its very nature as disquieting as the feeling in the mouth the artificial bonbon without being able to taste is for later experience. It is through the negations of customary coincident impressions that anticipation and desire become forced by the exigencies of life. The early psychism is limited in its adjustments to a very few simple coincidences, but in the struggle of life in complex nature there comes disruption of these primitive co-ordinations, and sequences become apprehended, and meaning is discerned in things. This disruption primitively occurred most easily when there was direct opposition to the usual course of sensations. Just as when mouthing the imitation bonbon, we apprehend most quickly and easily non-realization when it tastes sour rather than sweet. By realities continually breaking in upon the common course of psychic association, the significance of things is gradually apprehended, and to see a thing is understood not merely as coincident with other sensations and perceptions, touching, tasting, and pleasure-feeling, but the thing is cognized as centre of pleasure potency, and so can become object of desire. Experience loses its self-contained simplicity, and is forced in the struggle of experience in a complex environment into some definite understanding of things, and into a feeling for them or at them, and not merely a feeling from them. And so a world of desirables and aversibles is formed.