n the
assumption of a contriver, and all such hazy films as that of
variability producing variation cease to be capable of serving as
excuses for wilful blindness. And why should not the power in question
be so credited? Here is Mr. Darwin's solitary reason why. He doubts
whether the inference implied may not be 'presumptuous.' He apprehends
that we have no 'right to assume that the Creator works by intellectual
powers like those of a man.' Truly, of all suggested modes of marking
respect for creative power, that of assuming it to have worked
unintelligently is the most original.

The hypothesis offered by Mr. Darwin in explanation of the most perfect
of organic structures, is deemed by him to be equally explanatory of the
most marvellous of animal instincts. Parenthetically, here, never having
as yet met with a definition of instinct which I am able to accept as
satisfactory, I make bold to offer a description of my own. Instinct is
innate knowledge how to perform any useful actions, accompanied by a
tendency or propensity to perform those actions, but wholly
unaccompanied by knowledge of any purpose which they can serve. This is
pure instinct, an example whereof is afforded by the beaver, of which
animal I have somewhere read that one caught when newly born, and
brought up by itself in a room in its captor's house, proceeded after a
while to build up across the apartment the semblance of a dam, composed
of brushes, rugs, billets of wood, and other litter. Pure instinct
differs essentially, not in degree only, but in kind, from reason, which
is not knowledge, but an instrument for acquiring knowledge. Instinct,
however, is rarely if ever found pure, being apparently always
accompanied by more or less of reason. Even a polype makes some show of
reason by moving its _cilia_ in one mode when it desires to suck in
food, and in another when it merely wishes to move on; while it is
scarcely possible for an unprejudiced spectator to doubt of its being by
a rational deduction from experience that a dog knows that it will get
kicked if it presume to snatch at the meat on its master's plate,
instead of waiting for the scraps he may be pleased to throw to it when
he has done. Instinct by necessary implication involves habit; habit as
necessarily always more or less modifies structure; structural
modification always may be, and often is, inherited, carrying with it a
tendency to the habit out of which itself arose; therefore habit