The youth should first learn perspective, then the proportions of
objects. Then he may copy from some good master, to accustom himself
to fine forms. Then from nature, to confirm by practice the rules he
has learnt. Then see for a time the works of various masters. Then
get the habit of putting his art into practice and work.

[Footnote: The Vatican copy and numerous abridgements all place this
chapter at the beginning of the _Trattato_, and in consequence
DUFRESNE and all subsequent editors have done the same. In the
Vatican copy however all the general considerations on the relation
of painting to the other arts are placed first, as introductory.]