A painter who has clumsy hands will paint similar hands in his
works, and the same will occur with any limb, unless long study has
taught him to avoid it. Therefore, O Painter, look carefully what
part is most ill-favoured in your own person and take particular
pains to correct it in your studies. For if you are coarse, your
figures will seem the same and devoid of charm; and it is the same
with any part that may be good or poor in yourself; it will be shown
in some degree in your figures.
587.