INFLUENCE OF INTELLIGENCE ON INSTINCT 177 
But the dissolution of instincts is not complete. Residua 
are left in the inherited mental constitution. And these we 
term congenital tendencies and propensities. They differ from 
the typical instincts in the fact that the definiteness of response 
has been lost. They dictate a general trend of action, but 
the particular application in behaviour is due to intelligent 
accommodation. They are commonly spoken of as instinctive ; 
and their mode of origin justifies the use of the adjective in 
association with the term “ propensities.” But it must be 
remembered that the behaviour to which they lead is not, as 
such, wholly instinctive ; it is a joint product of instinct and 
intelligence, the general trend being due to the instinctive 
propensity, while the mode of application is guided by 
intelligence. 
There is, however, another way in which analogous pro- 
peusities may be ingrained in the mental constitution. It is 
a well-known and familiar fact that the frequent repetition 
of intelligent accommodation in certain definite lines begets 
habits, which so far simulate instincts as to be commonly 
described in popular speech as instinctive. Professor Wundt 
indeed places them in the category of ‘acquired instincts ”»— 
a usage which we regard as unsatisfactory, seeing that it tends 
to mask the distinction between the congenital and acquired 
factors in behaviour, and seeing that we have the well-defined 
term “habits” for acts rendered to a large extent automatic 
through repetition. Lamarckian thinkers regard habit as the 
mother of instinct, assuming that the acquired automatism of 
one generation may be transmitted to become congenital in 
the succeeding generation. This conclusion we provisionally 
reject regarding the basal assumption as at present unproven. 
But though we cannot accept the view that habit is the mother 
of instinct, we regard it as not improbable that habit may 
be the nurse of congenital propensities. Remembering that 
similar habits are acquired by animals of the same species 
throughout a series of succeeding generations, and assuming 
that congenital variations are constantly occurring in many 
directions, it seems probable that some of these variations will 
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