110 JOURNAL OF SCIENCE, 
and he was right. No biologist would deny that great results 
may proceed from small causes ; but all would certainly object 
to the deduction that therefore “a science of biology in the 
true sense of the term is an absurd notion.” This discussion is, 
I hope, sufficient to show that although the science of history is 
exceedingly difficult and complicated, it differs only in degree, 
not in kind, from the other inductive sciences. 
You ask why I am so interested in a science of history? 
What have I to do with it? I answer : History isa part of 
sociology, and sociology is but a branch of biology. It is the 
natural history of man, and must be approached through the 
study of biology. That sociology is dependent on biology was 
first definitely suggested by Auguste Compte, but he wrote before 
the principal laws of biology had been discovered ; he thought 
that the idea of continuous progress was peculiar to sociology, 
and consequently he failed to see the true connection between 
the two. It is to Mr Herbert Spencer that we are indebted for 
making this connection clear. He has shown that a preliminary 
study of biology is essential to the student of sociology, “ partly 
as familiarizing the mind with the cardinal ideas of continuity, 
complexity, and contingency of causation in clearer and more 
various ways than do other concrete sciences, and partly as 
familiarising the mind with the cardinal idea of fructifying causa- . 
tion (2.2. cumulative action), which the other concrete sciences 
do not present at all,’* but which is common to biology and 
sociology. He points out that “the human being is at once the 
terminal problem of biology and the initial factor of sociology.” 
As man is modifiable by surrounding conditions, it is necessary 
that the sociologist should acquaint himself with the laws of 
modification to which organised beings in general conform ; and 
he concludes by saying that “the effect to be looked for from 
the study of biology is that of giving strength and clearness to 
convictions otherwise feeble and vague.’ 
It might be thought that a knowledge of the principles of 
biology, unaccompanied by a knowledge of the facts upon 
which these principles rest, is sufficient for the student of 
sociology ; but this would be a great error. The principle of 
selection, although capable of being very simply stated, is in its 
action extremely complicated ; yet a thorough knowledge of it 
is essential to the historian as a guide to the kind of facts which 
are to be looked for, and as a means of estimating the relative 
importance of each. Without a firm conviction of the truth of 
the principle you are applying you will hardly surmount the 
difficulties that lie in your way, and you will perhaps abandon 
your problem in despair, doubting the possibility of a solution. 
This knowledge can only be got in one way—that is, by going 
through a practical course of biology. If you trust to book 
knowledge alone you will falter at every step. You must ob- 
serve for yourself in order to understand the difficulty of ob- 
* “Study of Sociology,” International Scientific Series, Vol. V. 
