Whatever you do in life, if you want to be creative and intelligent, and develop your brain, you must do everything with the awareness that everything, in some way, connects to everything else.

Men of lofty genius when they are doing the least work are most active.

Those who are inspired by a model other than Nature, labor in vain.

In fact, whatever exists in the universe, in essence, in appearance, in the imagination, the painter has first in his mind and then in his hands ... it lies in his power to create them . . .

No human investigation can claim to be scientific if it doesn't pass the test of mathematical proof.

The eye which turns from a white object in the light of the sun and goes into a less fully lighted place will see everything as dark.

The length of a man's outspread arms is equal to his height.