Water is the driving force of all nature.

O neglectful Nature, wherefore art thou thus partial, becoming to some of thy children a tender and benignant mother, to others a most cruel and ruthless stepmother? I see thy children given into slavery to others without ever receiving any benefit, and in lieu of any reward for the services they have done for them they are repaid by the severest punishments.

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.

One painter ought never to imitate the manner of any other; because in that case he cannot be called the child of nature, but the grandchild. It is always best to have recourse to nature, which is replete with such abundance of objects, than to the productions of other masters, who learnt everything from her.

Constancy does not begin, but is that which perseveres.

Darkness is absence of light. Shadow is diminution of light.

A good memory, which nature has endowed us with, causes things long past to seem present.