The good painter must paint two things: a person and the essence of his soul.
Of the original phenomena, light is the most enthralling.
An arch consists of two weaknesses which, leaning one against the other, make a strength.
Where there is most feeling, there is the greatest martyrdom.
Any color is more distinctly seen when opposed to its contrary: thus, black on white, blear near yellow, green near red, and so on.
While you are alone you are entirely your own master and if you have one companion you are but half your own, and the less so in proportion to the indiscretion of his behavior.