The Constructive Imagination selects its material. The person using the faculty in this manner abstracts from his general stock of mental images and impressions those particular materials which fit in with his general intent and purpose. Instead of allowing his imagination to wander around the entire field of memory, or representation, he deliberately and voluntarily selects and sets apart only such objects as seem to be conducive to his general design or plan, and which are logically associated with the same.
The Constructive Imagination operates upon the lines of logical thought. One so using the faculty subjects his mental images, or ideas, to his thinking faculties, and proceeds with his imaginative constructive work along the lines of Logical Thought. He goes through the processes of Abstraction, Generalization or Conception, Judgment and the higher phases of Reasoning, in connection with his general work of Constructive Imagination. Instead of having the objects of thought before him in material form, he has them represented to his mind in ideal form, and he works upon his material in that shape.
The Constructive Imagination is voluntary—under the control and direction of the will. Instead of being in the nature of a dream depending not upon the will or reason, it is directly controlled not only by reason but also by the will.
The Constructive Imagination, like every other faculty of the mind, may be developed and cultivated by Use and Nourishment. It must be exercised in order to develop its mental muscle; and it must be supplied with nourishment upon which it may grow. Drawing, Composing, Designing and Planning along any line is calculated to give to this faculty the exercise that it requires. The reading of the right kind of literature is also likely to lead the faculty into activity by inspiring it with ideals and inciting it by example.
The mind should be supplied with the proper material for the exercise of this faculty. As Halleck says: "Since the imagination has not the miraculous power necessary to create something out of nothing, the first essential thing is to get the proper perceptional material in proper quantity. If a child has enough blocks, he can build a castle or a palace. Give him but three blocks, and his power of combination is painfully limited. Some persons wonder why their imaginative power is no greater, when they have only a few accurate ideas." It thus follows that the active use of the Perceptive faculties will result in storing away a quantity of material, which, when represented or reproduced by the Memory, will give to the Constructive Imagination the material it requires with which to build. The greater the general knowledge of the person, the greater will be his store of material for this use. This knowledge need not necessarily be acquired at first hand from personal observation, but may also be in the nature of information acquired from the experience of others and known through their conversation, writings, etc.
The necessity of forming clear concepts is very apparent when we come to exercise the Constructive Imaginative. Unless we have clear-cut ideas of the various things concerned with the subject before us, we cannot focus the imagination clearly upon its task. The general ideas should be clearly understood and the classification should be intelligent. Particular things should be clearly seen in "the mind's eye;" that is, the power of visualization or forming mental images should be cultivated in this connection. One may improve this particular faculty by either writing a description of scenes or particular things we have seen, or else by verbally describing them to others. As Halleck says: "An attempt at a clear-cut oral description of something to another person will often impress ourselves and him with the fact that our mental images are hazy, and that the first step toward better description consists in improving them."
Tyndall has aptly stated the importance of visualizing one's ideas and particular concepts, as follows: "How, for example, are we to lay hold of the physical basis of light since, like that of life itself, it lies entirely without the domain of the senses?... Bring your imaginations once more into play and figure a series of sound-waves passing through air. Follow them up to their origin, and what do you there find? A definite, tangible, vibrating body. It may be the vocal chords of a human being, it may be an organ-pipe, or it may be a stretched string. Follow in the same manner a train of ether waves to their source, remembering at the same time that your ether is matter, dense, elastic and capable of motions subject to and determined by mechanical laws. What then do you expect to find as the source of a series of ether waves? Ask your imagination if it will accept a vibrating multiple proportion—a numerical ratio in a state of oscillation? I do not think it will. You cannot crown the edifice by this abstraction. The scientific imagination which is here authoritative, demands as the origin and cause of a series of ether waves a particle of vibrating matter quite as definite, though it may be excessively minute, as that which gives origin to a musical sound. Such a particle we name an atom or a molecule. I think the seeking intellect, when focused so as to give definition without penumbral haze, is sure to realize this image at the last."
By repeatedly exercising the faculty of Imagination upon a particular idea, we add power and clearness to that idea. This is but another example of the familiar psychological principle expressed by Carpenter as follows: "The continued concentration of attention upon a certain idea gives it a dominant power." Kay says: "Clearness and accuracy of image is only to be obtained by repeatedly having it in the mind, or by repeated action of the faculty. Each repeated act of any of the faculties renders the mental image of it more clear and accurate than the preceding, and in proportion to the clearness and accuracy of the image will the act itself be performed easily, readily, skillfully. The course to be pursued, the point to be gained, the amount of effort to be put forth, become more and more clear to the mind. It is only from what we have done that we are able to judge what we can do, and understand how it is to be effected. When our ideas or conceptions of what we can do are not based on experience, they become fruitful sources of error."
Galton says: "There is no doubt as to the utility of the visualizing faculty where it is duly subordinated to the higher intellectual operations. A visual image is the most perfect form of mental representation wherever the shape, position and relation of objects in space are concerned. It is of importance in every handicraft and profession where design is required. The best workmen are those who visualize the whole of what they propose to do before they take a tool in their hands."
Kay says: "If we bear in mind that every sensation or idea must form an image in the mind before it can be perceived or understood, and that every act of volition is preceded by its image, it will be seen that images play an important part in all our mental operations. According to the nature of the ideas or images which he entertains will be the character and conduct of the man. The man tenacious of purpose is the man who holds tenaciously certain ideas; the flighty man is he who cannot keep one idea before him for any length of time, but constantly flits from one to another; the insane man is he who entertains insane ideas often, it may be, on only one or two subjects. We may distinguish two great classes of individuals according to the prevailing character of their images. There are those in whose mind sensory images predominate, and those whose images are chiefly such as tend to action. Those of the former class are observant, often thoughtful, men of judgment and, it may be, of learning; but if they have not also the active faculty in due force, they will fail in giving forth or in turning to proper account their knowledge or learning, and instances of this kind are by no means uncommon. The man, on the other hand, who has ever in his mind images of things to be done, is the man of action and enterprise. If he is not also an observant and thoughtful man, if his mind is backward in forming images of what is presented to it from without, he will be constantly liable to make mistakes."