e human race attained a
longevity counted not by decades but by centuries. Alexander Humboldt
disbelieves the first of these propositions, Professor Owen disbelieves
the second. Men of science generally are of the same opinion. Few men of
science accept Adam and Eve, few accept Methuselah. Professor Owen
argues that, since the oldest skeletons known have the same system of
teething that we have, man can never have lived long enough to require
nine sets of teeth. In regard to these, and a hundred other points on
which science advances new views, the question which concerns us is how
we are to maintain the integrity of the intellectual life. The danger is
the loss of inward ingenuousness, the attempt to persuade ourselves that
we believe opposite statements. If once we admit disingenuousness into
the mind, the intellectual life is no longer serene and pure. The plain
course for the preservation of our honesty, which is the basis of truly
intellectual thinking, is to receive the truth, whether agreeable or the
contrary, with all its train of consequences, however repulsive or
discouraging. In attempting to reconcile scientific truth with the
oldest traditions of humanity, there is but one serious danger, the loss
of intellectual integrity. Of that possession modern society has little
left to lose.

But let us understand that the intellectual life and the religious life
are as distinct as the scientific and the artistic lives. They may be
led by the same person, but by the same person in different moods. They
coincide on some points, accidentally. Certainly, the basis of high
thinking is perfect honesty, and honesty is a recognized religious
virtue. Where the two minds differ is on the importance of authority.
The religious life is based upon authority, the intellectual life is
based upon personal investigation. From the intellectual point of view I
cannot advise you to restrain the spirit of investigation, which is the
scientific spirit. It may lead you very far, yet always to truth,
ultimately,--you, or those after you, whose path you may be destined to
prepare. Science requires a certain inward heat and heroism in her
votaries, notwithstanding the apparent coldness of her statements.
Especially does she require that intellectual fearlessness which accepts
a proved fact without reference to its personal or its social
consequences.

LETTER V.

TO A FRIEND WHO SEEMED TO TAKE CREDIT TO HIMSELF, INTELLECTUALLY, FROM
THE