before leaving offspring--still nine hundred and ninety-nine
thousandths of the movements necessary to achieve his end consist of
habitual movements--movements, that is to say, which were once difficult,
but which have been practised and practised by the help of memory until
they are now performed automatically. We can no more have an action than
a creative effort of the imagination cut off from memory. Ideas and
actions seem almost to resemble matter and force in respect of the
impossibility of originating or destroying them; nearly all that are, are
memories of other ideas and actions, transmitted but not created,
disappearing but not perishing.

It appears, then, that when in Chapter X. we supposed the clerk who
wanted his dinner to forget on a second day the action he had taken the
day before, we still, without perhaps perceiving it, supposed him to be
guided by memory in all the details of his action, such as his taking
down his hat and going out into the street. We could not, indeed,
deprive him of all memory without absolutely paralysing his action.

Nevertheless new ideas, new faiths, and new actions do in the course of
time come about, the living expressions of which we may see in the new
forms of life which from time to time have arisen and are still arising,
and in the increase of our own knowledge and mechanical inventions. But
it is only a very little new that is added at a time, and that little is
generally due to the desire to attain an end which cannot be attained by
any of the means for which there exists a perceived precedent in the
memory. When this is the case, either the memory is further ransacked
for any forgotten shreds of details a combination of which may serve the
desired purpose; or action is taken in the dark, which sometimes succeeds
and becomes a fertile source of further combinations; or we are brought
to a dead stop. All action is random in respect of any of the minute
actions which compose it that are not done in consequence of memory, real
or supposed. So that random, or action taken in the dark, or illusion,
lies at the very root of progress.

I will now consider the objection that the phenomena of instinct and
embryonic development ought not to be ascribed to memory, inasmuch as
certain other phenomena of heredity, such as gout, cannot be ascribed to
it.

Those who object in this way forget that our actions fall into two main
classes: those which we have often repeated bef