It reflects no great honor on a painter to be able to execute only one thing well -- such as a head, an academy figure, or draperies, animals, landscapes, or the like -- in other words, confining himself to some particular object of study. This is so because there is scarcely a person so devoid of genius as to fail of success if he applies himself earnestly to one branch of study and practices it continually.

Perspective is a most subtle discovery in mathematical studies, for by means of lines it causes to appear distant that which is near, and large that which is small.

Art is never finished, only abandoned.

In life beauty perishes, but not in art.

The painter who has no doubt about his own ability will attain very little.

He who has access to the fountain does not go to the water-pot.

Whoever in debate quotes authority uses not intellect, but memory.