Although human ingenuity may devise various inventions which, by the help of various instruments, answer to one and the same purpose, yet will it never discover any inventions more beautiful, more simple or more practical than those of nature, because in her inventions there is nothing lacking and nothing superfluous; and she makes use of no counterpoise when she constructs the limbs of animals in such a way as to correspond to the motion of their bodies, but she puts into them the soul of the body.

If you do not rest on the good foundation of nature, you will labour with little honor and less profit.

No human investigation can be called real science if it cannot be demonstrated mathematically.

Supreme happiness will be the greatest cause of misery, and the perfection of wisdom the occassion of folly.

Reprove your friend in secret and praise him openly.

He who truly knows has no occasion to shout.

The motive power is the cause of all life.