was investigating the general
laws of evolution and planning his Synthetic Philosophy which was to
explain the development of the universe. [Footnote: In an article on
"Progress: its Law and Cause," in the Westminster Review, April 1857,
Spencer explained that social progress, rightly understood, is not the
increase of material conveniences or widening freedom of action,
but changes of structure in the social organism which entail such
consequences, and proceeded to show that the growth of the individual
organism and the growth of civilisation obey the same law of advance
from homogeneity to heterogeneity of structure. Here he used progress
in a neutral sense; but recognising that a word is required which has no
teleological implications (Autobiography, i. 500), he adopted evolution
six months later in an article on "Transcendental Physiology" (National
Review, Oct. 1857). In his study of organic laws Spencer was indirectly
influenced by the ideas of Schelling through von Baer.] He aimed at
showing that laws of change are discoverable which control all phenomena
alike, inorganic, biological, psychical, and social. In the light of
this hypothesis the actual progression of humanity is established as a
necessary fact, a sequel of the general cosmic movement and governed
by the same principles; and, if that progression is shown to involve
increasing happiness, the theory of Progress is established. The first
section of the work, FIRST PRINCIPLES, appeared in 1862. The BIOLOGY,
the PSYCHOLOGY, and finally the SOCIOLOGY, followed during the next
twenty years; and the synthesis of the world-process which these volumes
lucidly and persuasively developed, probably did more than any other
work, at least in England, both to drive home the significance of the
doctrine of evolution and to raise the doctrine of Progress to the
rank of a commonplace truth in popular estimation, an axiom to which
political rhetoric might effectively appeal.

Many of those who were allured by Spencer's gigantic synthesis hardly
realised that his theory of social evolution, of the gradual psychical
improvement of the race, depends upon the validity of the assumption
that parents transmit to their children faculties and aptitudes which
they have themselves acquired. On this question experts notoriously
differ. Some day it will probably be definitely decided, and perhaps in
Spencer's favour. But the theory of continuous psychical improvement
by a process