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

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.

Necessity is the mistress and guide of nature.

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.