Common observation and a plain understanding is the source of all art.

It is but a poor eloquence which only shows that the orator can talk.

Invention strictly speaking, is little more than a new combination of those images which have been previously gathered and deposited in the memory; nothing can come from nothing.

The young mind is pliable and imitates, but in more advanced states grows rigid and must be warmed and softened before it will receive a deep impression.

The value and rank of every art is in proportion to the mental labor employed in it, or the mental pleasure in producing it.

In portraits, the grace and, we may add, the likeness consists more in taking the general air than in observing the exact similitude of every feature.

And he who does not know himself does not know others, so it may be said with equal truth, that he who does not know others knows himself but very imperfectly.