Therefore, O students, study mathematics and do not build without foundations.

We must doubt the certainty of everything which passes through the senses, but how much more ought we to doubt things contrary to the senses, such as the existence of God and the soul.

To such an extent does nature delight and abound in variety that among her trees there is not one plant to be found which is exactly like another; and not only among the plants, but among the boughs, the leaves and the fruits, you will not find one which is exactly similar to another.

A well-spent day brings happy sleep.

Study me, reader, if you delight in me, because on very few occasions shall I return to the world, and because the patience for this profession is found in very few, and only in those who wish to compose things anew. Come, oh men, to see the miracles that such studies will disclose to nature.

The painter's mind is a copy of the divine mind, since it operates freely in creating the many kinds of animals, plants, fruits, landscapes, countrysides, ruins, and awe-inspiring places.

I am not poor. Poor are those who desire many things.