74. THE HISTORY OF CREATION. 
conflagration, or of a railway accident, as of the creation of 
man.” (Jenaische Zestscrift, bd. v. p. 272.) 
In the face, then, of these hypotheses of creation, which 
are scientifically insufficient, we are forced to seek refuge in 
the counter-theory of development of organisms, if we wish 
to come to a rational conception of the origin of organ- 
isms. We are forced and obliged to do so, even if the theory 
of development only throws a glimmer of probability 
upon a mechanical, natural origin of the animal and vege- 
table species; but all the more if, as we shall see, this 
theory explains all facts simply and clearly, as well as com- 
pletely and comprehensively. The theories of develop- 
ment are by no means, as they often falsely are represented 
to be, arbitrary fancies, or wilful products of the imagination, 
which only attempt approximately to explain the origin of 
this or that individual organism; but they are theories 
founded strictly on science, which explain in the simplest 
manner, from a fixed and clear point of view, the whole of 
organic natural phenomena, and more especially the origin 
of organic species, and demonstrate them to be the necessary 
consequences of mechanical processes in nature. 
As I have already shown in the second chapter, all 
these theories of development coincide naturally with that 
general theory of the universe which is usually designated 
as the uniform or monistic, often also as the mechanical or 
causal, because it only assumes mechanical causes, or causes 
working by necessity (cause efticientes), for the explanation 
of natural phenomena. In like manner, on the other hand, 
the supernatural hypotheses of creation which we have al- 
ready discussed coincide completely with the opposite view 
of the universe, which in contrast to the former is called the 
