§ REACTION OF MAN ON NATURE. 
has been half awakened to the necessity of restoring the dis- 
turbed harmonies of nature, whose well-balanced influences are 
so propitious to all her organic offspring, and of repaying to our 
great mother the debt which the prodigality and the thrift- 
lessness of former generations have imposed upon their succes- 
sors—thus fulfilling the command of religion and of practical 
wisdom, to use this world as not abusing it. 
Reaction of Man on Nature. 
The revolutions of the seasons, with their alternations of 
temperature and of length of day and night, the climates of 
different zones, and the general conditions and movements of 
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 belong- 
ing 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 
depopulated, in many parts of the Continent, by civil and ecclesiastical 
tyrannies, which insisted on the surrender of the half of a loaf already too 
small to sustain its producer. Thus abandoned, these lands often relapsed 
into the forest state, and, some centuries later, were again brought under 
cultivation with renovated fertility. 
