Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity.

Vitality and beauty are gifts of Nature for those who live according to its laws.

Do not imitate one another's style. If you do, so far as your art is concerned you will be called a grandson, rather than the son of Nature. 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.

The body of the earth is of the nature of a fish, a grampus or sperm whale, because it draws water as its breath instead of air.

There is no result in nature without a cause; understand the cause and you will have no need of the experiment.

O mighty and once living instrument of formative nature. Incapable of availing thyself of thy vast strength thou hast to abandon a life of stillness and to obey the law which God and time gave to procreative nature.