174 OUTLINES OF FORESTRY. 



the atmosphere and the seas, depend upon causes for the most 

 part cosmical, and, of course, wholly beyond our control. 

 The elevation, configuration, and composition of the great 

 masses of terrestrial surface, and the relative extent and 

 distribution of land and water, are determined by geological 

 influences equally remote from our jurisdiction. It would 

 hence seem that the physical adaptation of different portions 

 of the earth to the use and enjoyment of man is a matter so 

 strictly belonging to mightier than human powers, that we 

 can only accept geographical nature as we find her, and be 

 content with such soils and such skies as she spontaneously 

 offers. 



" But it is certain that man has reacted upon organized and 

 inorganic nature, and thereby modified, if not determined, the 

 material structure of his earthly home. The measure of that, 

 reaction manifestly constitutes a very important element in 

 the appreciation of the relations between mind and matter, as 

 well as in the discussion of many purely physical problems. 

 But, though the subject has been incidentally touched upon 

 by many geographers, and treated with much fulness of detail 

 in regard to certain limited fields of human effort and to 

 certain specific effects of human action, it has not, as a whole, 

 so far as I know, been made a matter of special observation, 

 or of historical research, by any scientific inquirer. Indeed, 

 until the influence of geographical conditions upon human 

 life was recognized as a distinct branch of philosophical 

 investigation, there was no motive for the pursuit of such 

 speculations ; and it was desirable to inquire how far we have, 

 or can, become the architects of our own abiding-place, only 

 when it was known by the mode of our physical, moral, and 



