The imagination belongs to the general class of mental processes called the representative faculties, by which is meant the processes in which there are re-presented, or presented again, to consciousness impressions previously presented to it.
As we have indicated elsewhere, the imagination is dependent upon memory for its materials–its records of previous impressions. But imagination is more than mere memory or recollection of these previously experienced and recorded impressions. There is, in addition to the re-presentation and recollection, a process of arranging the recalled impressions into new forms and new combinations. The imagination not only gathers together the old impressions, but also _creates_ new combinations and forms from the material so gathered.
Psychology gives us many hairsplitting definitions and distinctions between simple reproductive imagination and memory, but these distinctions are technical and as a rule perplexing to the average student. In truth, there is very little, if any, difference between simple reproductive imagination and memory, although when the imagination indulges in constructive activity a new feature enters into the process which is absent in pure memory operations. In simple reproductive imagination there is simply the formation of the mental image of some previous experience–the reproduction of a previous mental image. This differs very little from memory, except that the recalled image is clearer and stronger. In the same way in ordinary memory, in the manifestation of recollection, there is often the same clear, strong mental image that is produced in reproductive imagination. The two mental processes blend into each other so closely that it is practically impossible to draw the line between them, in spite of the technical differences urged by the psychologists. Of course the mere remembrance of a person who presents himself to one is nearer to pure memory than to imagination, for the process is that of recognition. But the memory or remembrance of the same person when he is absent from sight is practically that of reproductive imagination. Memory, in its stage of recognition, exists in the child mind before reproductive imagination is manifested. The latter, therefore, is regarded as a higher mental process.
But still higher in the scale is that which is known as _constructive imagination_. This form of imagination appears at a later period of child mentation, and is regarded as a later evolution of mental processes of the race. Gordy makes the following distinction between the two phases of imagination: “The difference between reproductive imagination and constructive imagination is that the images resulting from reproductive imagination are _copies of past experience_, while those resulting from constructive imagination are not. * * * To learn whether any particular image, or combination of images, is the product of reproductive or constructive imagination, all we have to do is to learn whether or not it is a copy of a past experience. Our memories, of course, are defective, and we may be uncertain on that account; but apart from that, we need be in no doubt whatever.”
Many persons hearing for the first time the statement of psychologists that the imaginative faculties can re-present and re-produce or re-combine only the images which have previously been impressed upon the mind, are apt to object that they can, and frequently do, image things which they have not previously experienced. But can they and do they? Is it not true that what they believe to be original creations of the imagination are merely _new combinations_ of original impressions? For instance, no one ever saw a unicorn, and yet some one originally imagined its form. But a little thought will show that the image of the unicorn is merely that of an animal having the head, neck, and body of a horse, with the beard of a goat, the legs of a buck, the tail of a lion, and a long, tapering horn, spirally twisted, in the middle of the forehead. Each of the several parts of the unicorn exists in some living animal, although the unicorn, composed of all of these parts, is non-existent outside of fable. In the same way the centaur is composed of the body, legs, and tail of the horse and the trunk, head, and arms of a man. The satyr has the head, body, and arms of a man, with the horns, legs, and hoofs of a goat. The mermaid has the head, arms, and trunk of a woman, joined at the waist to the body and tail of a fish. The mythological “devil” has the head, body, and arms of a man, with the horns, legs, and cloven foot of the lower animal, and a peculiar tail composed of that of some animal but tipped with a spearhead. Each of these characteristics is composed of familiar images of experience. The imagination may occupy itself for a lifetime turning out impossible animals of this kind, but every part thereof will be found to correspond to something existent in nature, and experienced by the mind of the person creating the strange beast.
In the same way the imagination may picture a familiar person or thing acting in an unaccustomed manner, the latter having no basis in fact so far as the individual person or thing is concerned, but being warranted by some experience concerning other persons or things. For instance, one may easily form the image of a dog swimming under water like a fish, or climbing a tree like a cat. Likewise, one may form a mental image of a learned, bewigged High Chancellor, or a venerable Archbishop of Canterbury, dressed like a clown, standing on his head, balancing a colored football on his feet, sticking his tongue in his cheek and winking at the audience. In the same way one may imagine a railroad running across a barren desert, or a steep mountain, upon which there is not as yet a rail laid. The bridge across a river may be imaged in the same way. In fact, this is the way that everything is mentally created, constructed, or invented–the old materials being combined in a new way, and arranged in a new fashion. Some psychologists go so far as to say that no mental image of memory is an exact reproduction of the original impression; that there are always changes due to the unconscious operation of the constructive imagination.