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beings. But again opinions differ ; for some suppose that
the instinct and intelligence act apart from one another ;
while others believe that the intelligence interposes when
ever it is needed to modify instinct. Some believe that the
animal world was produced by a special act of creation,
and was endowed from the first with instincts and organ
isms adapted to the conditions in which they were placed ;
while others believe that instincts have been developed by
a process analogous to that of the evolution of organic
structures.
It will suffice for the purposes of the present argument
to affirm three principles. In the first place, if the prin
ciple of organic evolution be assumed, it is obvious that
instincts, no less than structures, must have been developed.
The probability of this assumption becomes very great
when we attempt to interpret the facts by the theory of
special creation on the one hand and that of evolution on
the other hand. The conception of instinct which is based
upon the idea of a special creation is fraught with the
utmost difficulty. On this hypothesis we cannot account
for the fact that some animals are born with instincts
which are imperfectly developed ; it leaves no room for
the growth of new instincts, unless we suppose that animals
are the subjects of new accessions of divine inspiration ; it
makes no provision for adaptation to new conditions which
render old instincts useless or injurious. Moreover this
view necessarily loses all its claim upon our belief as soon
as the doctrine of special creation, with which it has been
associated, is admitted to be untenable. On the other
hand it has been one of the greatest triumphs of the theory
of organic evolution to remove much confusion of thought.
This principle will account for all the anomalies associated
with the subject. If the principle of evolution be ad
mitted, we can understand at once how it has come to pass