Cognition undoubtedly began as a very crude sensation, as the barest movement towards objectifying sense, as a pure sensation without any image form, any direct perception of an object. In the order of disappearance of elements from consciousness, we note that sensation maintains itself through a long series, and is the last stage before pure feeling sets in. As heat stimulus is increased, sense of heat begins at a certain point, and increases up to a certain intensity of the stimulus and to a certain intensity of its own, when it rapidly vanishes, and in the agony on the verge of unconsciousness is lost in pure pain. We note also that the cognition of object, of thing, disappears before the sensation of heat does. A person burning to death is for a time conscious of the fire, which consciousness at length is lost in intense painful sensations of heat; and this in turn, at the acme of consciousness entirely disappears, leaving only pure pain. Further, the rise to full consciousness, as well as the fall to unconsciousness, also suggests bare sensation as the original cognition. If a hot iron be applied to one in deep sleep, the order of waking consciousness—apart from any dream order—is pure pain, then sensation of heat, then awareness of hot object, and also of part heated and paining. In our ordinary consciousness it is certainly very hard to even partially isolate the various elements. Sometimes, however, a person will say, “I have such a queer pain; I do not know what it is.” The psychosis thus indicated is evidently pain with a movement towards a sensation which yet is not realized. Sensation does not come though it is looked for; there is pain only, and unqualified save by the peculiarity of being unidentified. The sense of lack of sensation bewilders, because sensation is so constant for our psychic life; but in primitive mind there is no such feeling of queerness when sensation does not _come_, or it is not able to _attain_ it. This inwrought tendency to sense all our pains and pleasures, and to feel the lack if we do not, is evidently the result of a long evolution. Sensation is thus seen to be an activity which we exercise to give definition to our pure feelings; there is something unfulfilled for us if sensation does not _come_, and we may thus go out for it and interpret the pain in sense form by a will-effort. Primitive mind, however, does not achieve its sensations as incited by this indefinite sense of lack-queerness or strangeness, but through pain at some critical moment to obtain a suitable reaction. All sensation is at first, as we even now can faintly realize, by a severe effort, and is not a spontaneous, incoming impression. Paradoxical as is the expression, “we learn to know,” yet it contains a truth in that cognition is an attainment incited by the necessities of the organism. Necessity is the mother of invention, and knowledge is at first an invention which the organism hits upon to help it in the exigencies of