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that some animals are born with instincts perfect for the
work they have to do ; and other animals with imperfectly
developed instincts or mere instinctive tendencies. It ac
counts for the failure of instinct when the animal is placed
in a sphere of which its race has had no experience.
It justifies us in expecting a new development of instinct,
no less than new modifications of structure, to meet the
exigencies of new conditions.
In the second place we venture to assume that some
animals are intelligent and that their actions are sometimes
under the surveillance of their intelligence. It might be
difficult to prove that this was the case in some instances ;
as when, for example, animals are born with perfect instincts
which never require to be modified in the face of unchanged
conditions. But it is obvious that different animals are
born in different stages of development, both of organism
and of instinct. The bird which is hatched in a nest built
in a tree is at first utterly helpless and completely de
pendent upon its parents. The bird that is hatched in
a nest on the ground could not escape destruction unless it
were endowed with fully-developed powers of locomotion
and an instinctive knowledge of its parents’ cries of
warning or of invitation.
The power of the animal to correct its innate tendencies
of itself and to receive instruction from others, no less than
the power to impart instruction, implies a certain amount
of intelligence, and should serve to convince us, without
any elaborate argument, that animal experience is made
up of instinct and of intelligence. It is unnecessary for
my present purpose to enter at large into any proof that
all the actions of all animals are purely instinctive and
non-intelligent. In face of the simplest act of animal in
telligence, I refuse to bow to the dictum of utter scepticism
expressed by Bonnet, when he asserts that “ philosophers
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