escent of Man_ (1871), the hypothesis of Lamarck that man is the
co-descendant with other species of some lower extinct form was
admitted to have been raised to the rank of an established fact by
most thinkers whose brains were not working under the constraint of
theological authority.

One important effect of the discovery of this fact (I am not speaking
now of the Darwinian explanation) was to assign to history a definite
place in the coordinated whole of knowledge, and relate it more
closely to other sciences. It had indeed a defined logical place in
systems such as Hegel's and Comte's; but Darwinism certified its
standing convincingly and without more ado. The prevailing doctrine
that man was created _ex abrupto_ had placed history in an isolated
position, disconnected with the sciences of nature. Anthropology,
which deals with the animal _anthropos_, now comes into line with
zoology, and brings it into relation with history.[239] Man's
condition at the present day is the result of a series of
transformations, going back to the most primitive phase of society,
which is the ideal (unattainable) beginning of history. But that
beginning had emerged without any breach of continuity from a
development which carries us back to a quadrimane ancestor, still
further back (according to Darwin's conjecture) to a marine animal of
the ascidian type, and then through remoter periods to the lowest form
of organism. It is essential in this theory that though links have
been lost there was no break in the gradual development; and this
conception of a continuous progress in the evolution of life,
resulting in the appearance of uncivilised Anthropos, helped to
reinforce, and increase a belief in, the conception of the history of
civilised Anthropos as itself also a continuous progressive
development.

13. Thus the diffusion of the Darwinian theory of the origin of man,
by emphasising the idea of continuity and breaking down the barriers
between the human and animal kingdoms, has had an important effect in
establishing the position of history among the sciences which deal
with telluric development. The perspective of history is merged in a
larger perspective of development. As one of the objects of biology is
to find the exact steps in the genealogy of man from the lowest
organic form, so the scope of history is to determine the stages in
the unique causal series from the most rudimentary to the present
state of human civilisation.