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.

The water wears away the mountains and fills up the valleys, and if it had the power it would reduce the earth to a perfect sphere.

The air moves like a river and carries the clouds with it; just as running water carries all the things that float upon it.

Water is the driving force in nature.

To any white body receiving the light from the sun, or the air, the shadows will be of a bluish cast.

Nature is man's inorganic body - that is to say, nature insofar as it is not the human body. Man lives from nature - i.e., nature is his body - and he must maintain a continuing dialogue with it is he is not to die. To say that man's physical and mental life is linked to nature simply means that nature is linked to itself, for man is a part of nature.