To be sure, language itself may be regarded as imagery. Some persons visualize every word spoken as though it were seen on the printed page; others cannot recall a literary passage without motor imagery of the speech organs or even incipient speech; while others again experience motor imagery of the writing hand. With many, in all forms of word-consciousness, the auditory image is predominant. In the sense of being accompanied by imagery all thinking is imaginative. But it is the use of words that permits us to escape most completely from the more primitive forms of intelligence. So directly does the printed word convey its meaning to the trained mind that to regard it as so much black on white rather than as a symbol is a rare and rather upsetting mental experience. Words differ among themselves in their power to suggest images of the thing symbolized. The word "existence" is less image-producing than "flower," and "flower" than "red rose." It is characteristic of the language of science to substitute the abstract or general expression for the concrete and picturesque.
When, therefore, we are told that the imagination has been at the bottom of all great scientific discoveries, that the discovery of law is the peculiar function of the creative imagination, and that all great scientists have, in a certain sense, been great artists, we are confronted with a paradox. In what department of thought is imagination more strictly subordinated than in science? Genetic psychology attempts to trace the development of mind as a means of adjustment. It examines the instincts that serve so wonderfully the survival of various species of insects. It studies the more easily modified instinct of birds, and notes their ability to make intelligent choice on the basis of experience. Does the bird's ability to recognize imply the possession of memory, or imagery? Increased intelligence assures perpetuation of other species in novel and unforeseen conditions. The more tenacious the memory, the richer the supply of images, the greater the powers of adaptation and survival. We know something concerning the motor memory of rodents and horses, and its biological value. The child inherits less definitely organized instincts, but greater plasticity, than the lower animals. Its mental life is a chaos of images. It is the work of education to discipline as well as to nourish the senses, to teach form as well as color, to impart the clarifying sense of number, weight, and measurement, to help distinguish between the dream and the reality, to teach language, the treasure-house of our traditional wisdom, and logic, so closely related to the right use of language. The facts of abnormal, as well as those of animal and child psychology, prove that the subordination of the imagination and fancy to reason and understanding is an essential factor in intellectual development.