sake. The aim is to serve the spread of knowledge.

Our esthetic interest turns to the means by which the photoplay
influences the mind of the spectator. If we try to understand and to
explain the means by which music exerts its powerful effects, we do not
reach our goal by describing the structure of the piano and of the
violin, or by explaining the physical laws of sound. We must proceed to
the psychology and ask for the mental processes of the hearing of tones
and of chords, of harmonies and disharmonies, of tone qualities and tone
intensities, of rhythms and phrases, and must trace how these elements
are combined in the melodies and compositions. In this way we turn to
the photoplay, at first with a purely psychological interest, and ask
for the elementary excitements of the mind which enter into our
experience of the moving pictures. We now disregard entirely the idea of
the theater performance. We should block our way if we were to start
from the theater and were to ask how much is left out in the mere
photographic substitute. We approach the art of the film theater as if
it stood entirely on its own ground, and extinguish all memory of the
world of actors. We analyze the mental processes which this specific
form of artistic endeavor produces in us.

To begin at the beginning, the photoplay consists of a series of flat
pictures in contrast to the plastic objects of the real world which
surrounds us. But we may stop at once: what does it mean to say that the
surroundings appear to the mind plastic and the moving pictures flat?
The psychology of this difference is easily misunderstood. Of course,
when we are sitting in the picture palace we know that we see a flat
screen and that the object which we see has only two dimensions,
right-left, and up-down, but not the third dimension of depth, of
distance toward us or away from us. It is flat like a picture and never