All this, in the first place, has of course added an extraordinary richness and definition to our imaginative representation of the distant and unseen. Places and persons, forms of life and manufacturing processes are thus brought actually before our vision, if not before our senses, in their completeness. We are made familiar in advance with things which are to be seen only later in life, if at all; and our sympathetic participation in affairs at large is deepened as well as broadened. The greater world must be brought to the individual through the imagination if he is to come into contact with it at all, and pictorial representation vitalizes and reinforces this sense of understanding and community with mankind.
In more specific relations the picture-supplement facilitates our understanding, and this service has made it indispensable in bringing before the mind objects or processes whose constitution is too complex to be presented analytically, or to be reconstructed from a purely verbal description. In the lecture, just as in the book, illustration has a place not only legitimate, but important. Comprehension begins in intuition, and our sense of security in any general conception is weakened in proportion to the vagueness which marks our mental picture of its field. So long as photographs, stereopticon views and moving pictures perform this service, their use by the platform lecturer must be welcomed. Nevertheless, their function is a distinctly subordinate one—namely, the illustration of a theme which is itself still the essential preoccupation of the mind.
This relation has now significantly altered; the picture is advanced to the front rank and the theme has correspondingly fallen back. The very relation of speaker and screen in the illustrated lecture symbolizes this change. The lecturer stands in an obliterating shadow while all the energy of illumination is concentrated upon the stereopticon sheet. Even in its most elementary physical relations the focus of attention is thus shifted, and the change is significant of a profound modification in the relations of audience and lecturer. Language is an appeal to the mind, not to the eye; and its function is imperiled whenever this fact is obscured. The focusing of vision plays an important part in maintaining this intimate spiritual contact, and nothing more effectual in destroying it can well be conceived than the substitution of another point of regard so violent and alluring as the illuminated screen.
The extraordinary mechanical perfection of photography, its extension into the fields of panoramic, telescopic and micro-photography, and above all the development of motion pictures, have accelerated this adoption of a new attitude and the creation of a novel demand on the part of the audience. For one does not merely introduce a new medium in substituting pictures for discourse; the appeal is to a different side of human nature and satisfies an independent craving. Confronting facts
