KANT’S BIOLOGICAL THEORIES. IOI 
necessarily assume two fundamentally different natures : 
an wmorganic nature, which must be explained by causes 
acting mechanically (cause efficientes), and an organic 
nature, which must be explained by causes acting for a 
definite purpose (causze finales). (Compare p. 34.) 
This dualism meets us in a striking manner when con- 
sidering the conceptions of nature formed by Kant, one of 
the greatest German philosophers, and his ideas of the com- 
ing into being of organisms. A closer examination of these 
ideas is forced upon us here, because in Kant we honour one 
of the few philosophers who combine a solid scientific cul- 
ture with an extraordinary clearness and profundity of 
speculation. The Konigsberg philosopher gained the highest 
celebrity, not only among speculative philosophers as the 
founder of critical philosophy, but acquired a brilliant name 
also among naturalists by his mechanical cosmogeny. Even 
in the year 1755, in his “General History of Nature, and 
Theory of the Heavens,” he made the bold attempt “to 
discuss the constitution and the mechanical origin of the 
whole universe, according to Newton’s principles,” and to 
explain them mechanically by the natural course of develop- 
ment, to the exclusion of all miracles. This cosmogeny of 
Kant, or “cosmological gas theory,’ which we shall briefly 
discuss in a future chapter, was at a later day fully estab- 
lished by the French. mathematician Laplace and the Eng- 
lish astronomer Herschel, and enjoys at the present day 
almost universal recognition. On account of this import- 
ant work alone, in which exact knowledge is coupled 
with most profound speculation, Kant deserves the honour- 
able name of a natural philosopher in the best and purest 
sense of the word. 
