Chap. VII. 
INSTINCT LIKE HABIT. 
209 
If we suppose any habitual action to become inhe¬ 
rited—and I think it can be shown that this does 
sometimes happen—then the resemblance between what 
originally was a habit and an instinct becomes so close 
as not to be distinguished. If Mozart, instead of playing 
the pianoforte at three years old with wonderfully little 
practice, had played a tune with no practice at all, he 
might truly be said to have done so instinctively. But 
it would be the most serious error to suppose that the 
greater number of instincts have been acquired by habit 
in one generation, and then transmitted by inheritance 
to succeeding generations. It can be clearly shown that 
the most wonderful instincts with which we are ac¬ 
quainted, namely, those of the hive-bee and of many 
ants, could not possibly have been thus acquired. 
It will be universally admitted that instincts are 
as important as corporeal structure for the welfare 
of each species, under its present conditions of life. 
Under changed conditions of life, it is at least possible 
that slight modifications of instinct might be profitable 
to a species; and if it can be shown that instincts do 
vary ever so little, then I can see no difficulty in natural 
selection preserving and continually accumulating vari¬ 
ations of instinct to any extent that may be profitable. 
It is thus, as I believe, that all the most complex and 
wonderful instincts have originated. As modifications 
of corporeal structure arise from, and are increased by, 
use or habit, and are diminished or lost by disuse, so I do 
not doubt it has been with instincts. But I believe that 
the effects of habit are of quite subordinate importance 
to the effects of the natural selection of what may be 
called accidental variations of instincts ;—that is of vari¬ 
ations produced by the same unknown causes which pro¬ 
duce slight deviations of bodily structure. 
No complex instinct can possibly be produced through 
