=Retention and Recall.=--The facts already noted make it plain that apperception involves two important factors. First, apperception implies retention and recall. Unless our various experiences left behind them the permanent effects already noted in describing the retentive power of the nervous organism and the consequent possibility of recall, there could be no adjustment to new impressions on the basis of earlier experiences.
=Attention.=--Secondly, apperception involves attention. Since to apperceive is to bring the results of earlier experience to bear actively upon the new impression, it must involve a reactive, or attentive, state of consciousness; for, as noted in our study of the learning process, it is only by selecting elements out of former experience that the new impression is given definite meaning in consciousness. For the child to apperceive the strange object as a "bug-in-a-basket," demands from him therefore a process of attention in which the ideas "bug" and "basket" are selected from former experience and read into the new impression, thereby giving it a meaning in consciousness. A reference to any of the lesson topics previously considered will provide further examples of these apperceptive factors.
=Nature of.=--In our study of the various modes of acquiring individual notions, attention was called to the fact that knowledge of a particular object may be gained through a process of imagination. Like memory, imagination is a process of re-presentation, though differing from it in certain important regards.
1. Although imagination depends on past experiences for its images, these images are used to build up ideal representations of objects without any reference to past time.
2. In imagination the associated elements of past experience may be completely dissociated. Thus a bird may be imagined without wings, or a stone column without weight.
3. The dissociated elements may be re-combined in various ways to represent objects never actually experienced, as a man with wings, or a horse with a man's head.
Imagination is thus an apperceptive process by which we construct a mental representation of an object without any necessary reference to its actual existence in time.