have a theory which they have accepted; and, if you bring them a truth
with ever such overwhelming credentials which clashes with this
preconceived idea or prejudice, the chances are that it would be met
with doubt, with denial, not a clear-cut, intelligent, well- balanced
doubt, but a doubt that springs out of the unwillingness that a man
feels to reconstruct his theory.

Let me give you an illustration of what I mean, and this away off in
another department of life from our own, so that it will not clash with
any of your particular prejudices. Sir Isaac Newton won a great and
world-wide renown, and magnificently deserved, by his grand discovery
of the law of gravity. You will see, then, how natural it was for
people to pay deference to his opinion, to be prejudiced in favor of
his conclusions. It was perfectly natural and, within certain limits,
perfectly right. Sir Isaac Newton not only propounded this law of
gravity, but he propounded a theory of light which the world has since
discovered to be wrong. But it was universally accepted because it was
his. It became the accepted scientific theory of the time. By and by a
man, unknown up to that time, by the name of Young, studied Newton's
theory, and became convinced that it was wrong; and he propounded
another theory, the one which to- day is universally accepted through
the civilized world. But it was years before it could gain anything
like adequate or fair consideration, because the preconception in favor
of Newton's theory stood in the way of any adequate consideration of
the one which was subsequently universally adopted.

So you will find scientific men, I know any quantity of them, grand in
their fields, doing fine work, who are not willing to consider anything
which would compel a reconstruction of their theories and ideas. This
is true not only in the scientific field, but it is true everywhere: it