The Theory of Sexual Selection. 413 
done nothing in the way of negativing that belief in a 
Supreme Being which it was the object of these 
authors to substantiate. If it has demonstrated the 
futility of their proof, it has furnished nothing in the 
way of disproof. It has shown, indeed, that their line 
of argument was misjudged when they thus sought 
to separate organic nature from inorganic as a theatre 
for the special or peculiar display of supernatural 
design ; but further than this it has not shown anything. 
The change in question therefore, although greater in 
degree, is the same in kind as all its predecessors: like 
all previous advances in cosmological theory which 
have been wrought by the advance of science, this 
latest and greatest advance has been that of revealing 
the constitution of nature, or the method of causation, 
as everywhere the same. But it is evident that this 
change, vast and to all appearance final though it be, 
must end within the limits of natural causation itself. 
The whole world of life and mind may now have been 
annexed to that of matter and energy as together 
constituting one magnificent dominion, which is 
everywhere subject to the same rule, or method of 
government. But the ulterior and ultimate question 
touching the nature of this government as mental or 
non-mental, personal or impersonal, remains exactly 
where it was. Indeed, this is a question which cannot 
be affected by ay advance of science, further than 
science has proved herself able to dispose of erroneous 
arguments based upon ignorance of nature. For while 
the sphere of science is necessarily restricted to that 
of natural causation which it is her office to explore, 
the question touching the xature of this natural 
causation is one which as necessarily lies without the 
