invention is not
satisfactory unless it will really work, and sets about learning what
will work and what not, so accumulating observations that later enable
him to criticize his own ideas, to some extent, before trying them out
on real things.

Criticism is directed upon the individual from the side of other
people, who from the day he first begins to tell his childish
imaginings, are quite free with their objections. Humiliated by this
critical reception of his ideas, the individual may resolve to keep
them to himself for the future, and draw away, again, towards autistic
thinking; or, more forcefully, he may exert himself to find some idea
that will command the approval of other people. If he can take rebuffs
goodnaturedly, he soon finds that social criticism can be a great
help, that two heads are better than one in planning any invention
that needs to work. He accumulates knowledge of what will pass muster
when presented to other people, and thus again learns self-criticism.

Self-criticism is helped by such rules as to "think twice", to "sleep
on it before deciding", to "drop the matter for a time and come back
to it and see whether it still looks {511} the same". When you are all
warmed up over an idea, its recency value gives it such an advantage
over opposing ideas that they have no chance, for the moment, of
making themselves felt in the line of criticism.

I once heard the great psychologist, and great writer, William James,
make a remark that threw some light on his mode of writing. In the
evening, he said, after warming up to his subject, he would write on
and on till he had exhausted the lead he was following, and lay the
paper aside with the feeling, "Good! Good! That's good". The next
morning, he said, it might not seem good at all. This calls to mind
the old advice to writers about its being "better to compose with fury
and correct with phlegm than to compose with phlegm and correct with
fury". The phlegmatic critical attitude interferes considerably with
the enthusiastic inventive activity. Give invention free rein for the
time being, and come around with criticism later.

Some over-cautious and too self-critical persons, though rather
fertile in ideas, never accomplish much in the way of invention
because they cannot let themselves go. Criticism is always at their
elbow, suggesting doubts and alternatives and preventing progress in
the creative activity, instead of biding its time and coming in to