
	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
