s preservation, during the battle for life, of varieties which possess
any advantage in structure, constitution, or instinct, I have called
Natural Selection; and Mr. Herbert Spencer has well expressed the same idea
by the Survival of the Fittest. The term "natural selection" is in some
respects a bad one, as it seems to imply conscious choice; but this will be
disregarded after a little familiarity. No one objects to chemists speaking
of "elective affinity;" and certainly an acid has no more choice in
combining with a base, than the conditions of life have in determining
whether or not a new form be selected or preserved. The term is so far a
good one as it brings into connection the production of domestic races by
man's power of selection, and the natural preservation of varieties and
species in a state of nature. For brevity sake I sometimes speak of natural
selection as an intelligent power;--in the same way as astronomers speak of
the attraction of gravity as ruling the movements of the planets, or as
agriculturists speak of man making domestic races by his power of
selection. In the one case, as in the other, selection does nothing without
variability, and this depends in some manner on the action of the
surrounding circumstances on the organism. I have, also, often personified
the word Nature; for I have found it difficult to avoid this ambiguity; but
I mean by nature only the aggregate action and product of many natural
laws,--and by laws only the ascertained sequence of events. {7}

In the chapter devoted to natural selection I shall show from experiment
and from a multitude of facts, that the greatest amount of life can be
supported on each spot by great diversification or divergence in the
structure and constitution of its inhabitants. We shall, also, see that the
continued production of new forms through natural selection, which implies
that each new variety has some advantage over others, almost inevitably
leads to the extermination of the older and less improved forms. These
latter are almost necessarily intermediate in structure as well as in
descent between the last-produced forms and their original parent-species.
Now, if we suppose a species to produce two or more varieties, and these in
the course of time to produce other varieties, the principle of good being
derived from diversification of structure will generally lead to the
preservation of the most divergent varieties; thus the lesser differences
ch