Such are many disquisitions which I have read on some of the cartoons and
other pictures of Raffaelle, where the critics have described their own
imagination; or indeed where the excellent master himself may have
attempted this expression of passions above the powers of the art; and
has, therefore, by an indistinct and imperfect marking, left room for
every imagination, with equal probability to find a passion of his own.
What has been, and what can be done in the art, is sufficiently
difficult; we need not be mortified or discouraged for not being able to
execute the conceptions of a romantic imagination. Art has its
boundaries, though imagination has none. We can easily, like the
ancients, suppose a Jupiter to be possessed of all those powers and
perfections which the subordinate Deities were endowed with separately.
Yet, when they employed their art to represent him, they confined his
character to majesty alone. Pliny, therefore, though we are under great
obligations to him for the information he has given us in relation to the
works of the ancient artists, is very frequently wrong when he speaks of
them, which he does very often in the style of many of our modern
connoisseurs. He observes that in a statue of Paris, by Fuphranor, you
might discover at the same time three different characters; the dignity
of a judge of the goddesses, the lover of Helen, and the conqueror of
Achilles. A statue in which you endeavour to unite stately dignity,
youthful elegance, and stern valour, must surely possess none of these to
any eminent degree.

From hence it appears that there is much difficulty as well as danger in
an endeavour to concentrate upon a single subject those various powers
which, rising from different points, naturally move in different
directions.