It is a profoundly erroneous truism, repeated by all copy-books and
by eminent people when they are making speeches, that we should cultivate
the habit of thinking about what we are doing. The precise opposite is
the case. Civilization advances by extending the numbers of important
operations which we can perform without thinking about them.
Operations of thought are like cavalry charges in battle -- they
are strictly limited in number, they require fresh horses, and must only
be made at decisive moments.
-- Alfred North Whitehead
