APPERCEPTION, in psychology, a term used to describe the presentation of an object, on which attention is fixed, in rela tion to the previous experiences of the mind as a whole. The word was first used by Leibniz, practically in the sense of the modern Attention (q.v.), by which an object is apprehended as "not-self" and yet in relation to the self. In Kantian terminology apper is (I) transcendental—the perception of an object as , involving the consciousness of the pure self as subject, and (2) empirical—the cognition of the self in its concrete existence. In (1) apperception is almost equivalent to self-consciousness; the existence of the ego may be more or less prominent, but it is al ways involved. According to J. F. Herbart (q.v.) apperception is that process by which an aggregate or "mass" of presentations becomes systematized by the accretion of new elements, either sense-given or supplied by the inner workings of the mind. He thus emphasizes in apperception the connection with self as the result of all its previous experience. Hence in education the teacher should fully acquaint himself with the mental develop ment of the pupil, in order that he may make full use of what the pupil already knows.
Apperception is thus a general term for all mental processes in which a presentation is brought into connection with already existent and systematized ideas, and is thus classified, explained, or, in a word, understood. Thus a new scientific phenomenon is usually assimilated to other phenomena already analysed and classified. The whole intelligent life of man is, consciously or unconsciously, a process of apperception, inasmuch as every act of attention involves the appercipient process.
See K. Lange, Ueber Apperception (6th ed. rev. Leipzig, 1899), trans. E. E. Brown (Boston, 1893) ; G. F. Stout, Analytic Psychology, bk. ii. ch. viii. 1st ed. (1896) , later ed. (1902) ; E. N. MacQueen, The Distribution of Attention (1917).