All our knowledge is the offspring of our perceptions.

The painter strives and competes with nature.

A wave is never found alone, but is mingled with as many other waves as there are uneven places in the object where the said wave is produced.

The greater the man's soul, the deeper he loves.

The acquisition of knowledge is always of use to the intellect, because it may thus drive out useless things and retain the good. For nothing can be loved or hated unless it is first known.

For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return.

You should look at certain walls stained with damp, or at stones of uneven color. If you have to invent some backgrounds you will be able to see in these the likeness of divine landscapes, adorned with mountains, ruins, rocks, woods, great plains, hills and valleys in great variety; and expressions of faces and clothes and an infinity of things which you will be able to reduce to their complete and proper forms. In such walls the same thing happens as in the sound of bells, in whose stroke you may find every named word which you can imagine.