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.
Product of Imagination, Particular.—It is to be noted that in a process of imagination the mind always constructs in idea a representation of a particular object or individual. For instance, the ideal picture of the house I imagine situated on the hill before me is that of a particular house, possessing definite qualities as to height, size, colour, etc. In like manner, the future visit to Toronto, as it is being run over ideally, is constructed of particular persons, places, and events. So also when reading such a stanza as:
The milk-white blossoms of the thorn
Are waving o'er the pool,
Moved by the wind that breathes along,
So sweetly and so cool;
if the mind is able to combine into a definite outline of a particular situation the various elements depicted, then the mental process of the reader is one of imagination. It is not true, of course, that the particular elements which enter into such an ideal representation are always equally vivid. Yet one test of a person's power of imagination is the definiteness with which the mind makes an ideal representation stand out in consciousness as a distinct individual.
TYPES OF IMAGINATION
A. Passive.—In dissociating the elements of past experience and combining them into new particular forms, the mind may proceed in two quite different ways. In some cases the mind seemingly allows itself to drift without purpose and almost without sense, building up fantastic representations of imaginary objects or events. This happens especially in our periods of day-dreaming. Here various images, evidently drawn from past experience, come before consciousness in a spontaneous way and enter into most unusual forms of combination, with little regard even to probability. In these moods the timid lad becomes a strong hero, and his rustic Audrey, a fair lady, for whose sake he is ever performing untold feats of valour. Here the ideas, instead of being selected and combined for a definite purpose through an act of voluntary attention, are suggested one after the other by the mere law of association. Because in such fantastic products of the imagination the various images appear in consciousness and combine themselves without any apparent control or purpose, the process is known as passive imagination, or phantasy. Such a type, it is evident, will have little significance as an actual process of learning.
B. Active, or Constructive.—Opposed to the above type is that form of imagination in which the mind proceeds to build up a particular ideal representation with some definite purpose, or end, in view. A student, for example, who has never seen an aeroplane and has no direct knowledge of the course to be traversed, may be called upon in his composition work to describe an imaginary voyage through the air from Toronto to Winnipeg. In such an act of imagination, the selecting of elements to enter into the ideal picture must be chosen with an eye to their suitability to the end in view. When also a child is called upon in school to form an ideal representation of some object of which he has had no direct experience, as for instance, a mental picture of a volcano, he must in the same way, under the guidance of the teacher, select and combine elements of his actual experience which are adapted to the building up of a correct mental representation of an actual volcano. This type of imagination is known as active, or constructive, imagination.