A well-spent day brings happy sleep.

Movement will fail sooner than usefulness.

Those who are enamoured of practice without science are like a pilot who goes into a ship without rudder or compass and never has any certainty of where he is going. Practice should always be based upon a sound knowledge of theory.

The senses are of the earth, the reason stands apart from them in contemplation.

O time! swift devourer of all created things!

How painting surpasses all human works by reason of the subtle possibilities which it contains.

It is a far worthier thing to read by the light of experience than to adorn oneself with the labors of others.