A deaf and dumb person who sees two men in conversation - may nevertheless understand from the attitudes and gestures of the speakers, how well their discussion is getting along.

Nature is full of infinite causes that have never occurred in experience.

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.

It is ordained that to the ambitious, who derive no satisfaction from the gifts of life and the beauty of the world, life shall be a cause of suffering, and they shall possess neither the profit nor the beauty of the world.

Man has much power of discourse which for the most part is vain and false; animals have but little, but it is useful and true, and a small truth is better than a great lie.

The mind that engages in subjects of too great variety becomes confused and weakened.

Nature alone is the master of true genius.