es before it, and he
should be freed from all other cares. And if, while considering and
examining one subject, a second should intervene, as happens when an
object occupies the mind, he ought to decide which of these subjects
presents greater difficulties in investigation, and follow that until it
becomes entirely clear, and afterwards pursue the investigation of the
other. And above all he should keep his mind as clear as the surface of
a mirror, which becomes changed to as many different colours as are
those of the objects within it, and his companions should resemble him
in a taste for these studies; and if he fail to find any such, he should
accustom himself to be alone in his investigations, for in the end he
will find no more profitable companionship.

_Leonardo._

LI

If you are fond of copying other Men's Work, as being Originals more
constant to be seen and imitated than any living Object, I should rather
advise to copy anything moderately carved than excellently painted: For
by imitating a Picture, we only habituate our Hand to take a mere
Resemblance; whereas by drawing from a carved Original, we learn not
only to take this Resemblance, but also the true Lights.

_Leon Battista Alberti._

LII

There are a thousand proofs that the old masters and all good painters
from Raphael onwards executed their frescoes from cartoons and their
little easel pictures from more or less finished drawings.... Your model
gives you exactly what you want to paint neither in character of drawing
nor in colour, but at the same time you cannot do without him.

To paint Achilles the most goodly of men, though you had for your model
the most abject you must depend on him, and can depend on him for the
structure of the human body, for its movement and poise. The proof of
this is that Raphael used his pupils in his studies for the movements of
the figures in his divine pictures.

Whatever your talents may be, if you paint not from your studies after
nature, but directly from the model, you will always be a slave and your
pictures will show it. Raphael, on the contrary, had so completely
mastered nature and had his mind so full of her, that instead of being
ruled by her, one might say that she obeyed him and came at his command
to place herself in his pictures.

_Ingres._

LIII

No one can ever design till he has learned the language of Art by making
many finished copies both of Nature, Art, and of whatever comes in