Another branch of painting which began
to attain importance in the time of
Polygnotus was
scene-painting for theatrical performances. It may be,
as has been conjectured, that the impulse toward a style
of work in which a greater degree of illusion was aimed
at and secured came from this branch of the art. We
read, at any rate, that one Agatharchus, a scene-painter
who flourished about the middle of the fifth century,
wrote a treatise which stimulated two philosophers to an
investigation of the laws of perspective.
The most important technical advance,
however, is attributed to Apollodorus of Athens, a
painter of easel pictures. He departed from the old
method of coloring in flat tints and introduced the
practice of grading colors according to the play of
light and shade. How successfully he managed this
innovation we have no means of knowing; probably very
imperfectly. But the step was of the utmost
significance. It meant the abandonment of mere colored
drawing and the creation of the genuine art of painting.