Consumption is also immediately production, just as in nature the consumption of the elements and chemical substances is the production of the plant.

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.

He who is not content to look, like a savage, at the phenomena of nature as disconnected, cannot any longer believe that man is the work of a separate act of creation ... Man is the co-descendant with other mammals of a common progenitor.

The first premise of all human history is, of course, the existence of living human individuals. Thus the first fact to be established is the physical organisation of these individuals and their consequent relation to the rest of nature.

One touch of nature makes the whole world kin.

Look deep into nature, and then you will understand everything better.