n himself was conscious that his principles had only a
very restricted application in this sphere, as is evident from his
cautious and tentative remarks in the 5th chapter of his _Descent of
Man_. He applied natural selection to the growth of the intellectual
faculties and of the fundamental social instincts, and also to the
differentiation of the great races or "sub-species" (Caucasian,
African, etc.) which differ in anthropological character.[241]

16. But if it is admitted that the governing factors which concern the
student of social development are of the psychical order, the
preliminary success of natural science in explaining organic evolution
by general principles encouraged sociologists to hope that social
evolution could be explained on general principles also. The idea of
Condorcet, Buckle, and others, that history could be assimilated to
the natural sciences was powerfully reinforced, and the notion that
the actual historical process, and every social movement involved in
it, can be accounted for by sociological generalisations, so-called
"laws," is still entertained by many, in one form or another.
Dissentients from this view do not deny that the generalisations at
which the sociologist arrives by the comparative method, by the
analysis of social factors, and by psychological deduction may be an
aid to the historian; but they deny that such uniformities are laws or
contain an explanation of the phenomena. They can point to the element
of chance coincidence. This element must have played a part in the
events of organic evolution, but it has probably in a larger measure
helped to determine events in social evolution. The collision of two
unconnected sequences may be fraught with great results. The sudden
death of a leader or a marriage without issue, to take simple cases,
has again and again led to permanent political consequences. More
emphasis is laid on the decisive actions of individuals, which cannot
be reduced under generalisations and which deflect the course of
events. If the significance of the individual will had been
exaggerated to the neglect of the collective activity of the social
aggregate before Condorcet, his doctrine tended to eliminate as
unimportant the roles of prominent men, and by means of this
elimination it was possible to found sociology. But it may be urged
that it is patent on the face of history that its course has
constantly been shaped and modified by the wills of individuals,[2