CHAPTER 2A VII 
THEORY OF EVOLUTION 
In Chapter VI. we indicated the nature of the evidence 
which has led naturalists to accept the doctrine of descent 
as a modal interpretation of organic nature. The data of 
physiology and morphology, combined with what is known 
of the history of the race and the development of the 
individual, have led us to believe that the forms of life now 
around us are descended from simpler ancestors (except in 
cases of degeneration), and these from still simpler, and so 
on, back to the mist of life’s beginnings. In other words, 
we believe that the present is the child of the past and the 
parent of the future. This is the general idea of evolution. 
But while this general idea, which is a very grand one, is 
usually recognised as the simplest interpretation of the 
facts, we remain in doubt as to the factors of the process by 
which the world of life has come to be what it is. This 
uncertainty is in part due to the complexity of the problem, 
in part to the relative novelty of the inquiry—for precise 
etiology is not yet fifty years old—in part also to the fact 
that, while there has been much theorising, there has been 
comparatively little experimenting or connected observation 
as to the modes and causes of evolution. 
With the exception of Dr. Alfred Russel Wallace and a 
few others, who believe that it is necessary to postulate 
spiritual influxes to account for certain obscure beginnings, 
e.g. of the higher human qualities, evolutionists are agreed 
in seeking to explain the evolution of plants and animals 
as a continuous “natural” ‘process, the end of which was 
implicit in the beginning. In so doing, they follow the 
method of analysis, endeavouring to explain the facts in 
their lowest terms. But as the biologist’s lowest term is 
