We have above elaborated the fiction of a primitive psychic apparatus, whose work is regulated by the efforts to avoid accumulation of excitement and as far as possible to maintain itself free from excitement. For this reason it was constructed after the plan of a reflex apparatus; the motility, originally the path for the inner bodily change, formed a discharging path standing at its disposal. We subsequently discussed the psychic results of a feeling of gratification, and we might at the same time have introduced the second assumption, viz. that accumulation of excitement--following certain modalities that do not concern us--is perceived as pain and sets the apparatus in motion in order to reproduce a feeling of gratification in which the diminution of the excitement is perceived as pleasure. Such a current in the apparatus which emanates from pain and strives for pleasure we call a wish. We have said that nothing but a wish is capable of setting the apparatus in motion, and that the discharge of excitement in the apparatus is regulated automatically by the perception of pleasure and pain. The first wish must have been an hallucinatory occupation of the memory for gratification. But this hallucination, unless it were maintained to the point of exhaustion, proved incapable of bringing about a cessation of the desire and consequently of securing the pleasure connected with gratification. Thus there was required a second activity--in our terminology the activity of a second system--which should not permit the memory occupation to advance to perception and therefrom to restrict the psychic forces, but should lead the excitement emanating from the craving stimulus by a devious path over the spontaneous motility which ultimately should so change the outer world as to allow the real perception of the object of gratification to take place. Thus far we have elaborated the plan of the psychic apparatus; these two systems are the germ of the Unc. and Forec, which we include in the fully developed apparatus.