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 become enamoured of the art, without having previously applied to the diligent study of the scientific part of it, may be compared to mariners who put to the sea in a ship without rudder or compass and therefore cannot be certain of arriving at the wished for port.

Fame alone raises herself to Heaven, because virtuous things are in favour with God.

He who is fixed to a star does not change his mind.

There are three classes of people: those who see, those who see when they are shown, those who do not see.

I have offended God and mankind because my work didn't reach the quality it should have.

Painting is poetry that is seen rather than felt, and poetry is painting that is felt rather than seen.