The good painter must paint two things: a person and the essence of his soul.

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.

Those who fall in love with practice without science are like a sailor who enters a ship without a helm or a compass, and who never can be certain whither he is going.

There are many kinds of beauty as people who possess it.

Every part is disposed to unite with the whole, that it may thereby escape from its own incompleteness.

The eye encompasses the beauty of the whole world.

A bird is an instrument working according to mathematical law, which instrument it is within the capacity of man to reproduce with all its movements.