"I know that most men -- not only those considered clever,
but even those who are very clever and capable of understanding
most difficult scientific, mathematical, or philosophic, problems --
can seldom discern even the simplest and most obvious truth if it be such
as obliges them to admit the falsity of conclusions they have formed,
perhaps with much difficulty -- conclusions of which they are proud,
which they have taught to others, and on which they have built their lives."