"Painting is an imitation by means of lines and colors, on some
superfices, of everything that can be seen under the sun; its end is to
please.
_Principles that every man capable of reasoning may learn:_--There can
be nothing represented,
Without light,
Without form,
Without color,
Without distance,
Without an instrument, or medium.
_Things which are not to be learned, and which make an essential part of
painting._
First, the subject must be noble. It should have received no quality
from the mere workmen; and to allow scope to the painter to display his
powers, he should choose it capable of receiving the most excellent
form. He must begin by composition, then ornament, propriety, beauty,
grace, vivacity, probability, and judgment, in each and all. These last
belong solely to the painter, and cannot be taught. The nine are the
golden bough of Virgil, which no man can find or gather, if his fate do
not lead him to it."