ABSTRACT
Psychology may gather statistical data which have certain relevance due to the general similarity of different subjects. The diversities of subjective activity have, from the time of Immanuel Kant, been classified into the three categories of Cognition, Conation, and Feeling. The facts of psychic blindness indicate that awareness of the sensum require a further subjective reaction, which, in its cognitive character, grasps the presented sensum and intuition of body in their temporal relation as about to be followed by some further presentations, not necessarily different. The elaboration of physical structure which makes sensation possible requires an elaboration of psychical structure in order that there may be awareness of sensa. Many attempts have been made to argue from this elaboration of cognitive acts, and particularly from the fact of self-consciousness, to the existence of cognitive acts which are entirely independent of any physical basis.
