imitate and to repeat. The sheer existence of modern states depends
less on the crude physical force and its personified agencies, than on
the moral cohesion of the personalities who constitute the nation.

Since the beginning of time, it is only the moral values that have
endured. Force can support the state only temporarily. When a nation
disregards the moral forces and seeks its salvation in the rude clash of
arms, it bears within itself the seeds of its own destruction. No army
in the world is strong enough to maintain a state, the moral basis of
which is shaken, for the strength of the army rests upon its morale.

The importance of personality in the historic life of peoples is
manifest in periods when social conditions accelerate the movement of
social life. Personality, like every other force, reaches its maximum
when it encounters resistance, in conflict and in rivalry--when it
fights--hence its great value in friendly rivalry of nations in industry
and culture, and especially in periods of natural calamities or of
enemies from without. Since the fruits of individual development
contribute to the common fund of social values, it is clear that
societies and peoples which, other things being equal, possess the most
advanced and active personalities contribute most to the enrichment of
civilization. It does not seem necessary to demonstrate that the pacific
competition of nations and their success depends on the development of
the personalities which compose them. A nation weak in the development
of individualities, of social units which compose it, could not defend
itself against the exploitation of nations composed of personalities
with a superior development.

D. BIOLOGICAL AND SOCIAL HEREDITY

1. Nature and Nurture[75]

We have seen that the scientific position in regard to the
transmissibility of modifications should be one of active scepticism,
that there seems to be no convincing evidence in support of the
affirmative position, and that there is strong presumption in favor of
the negative.

A modification is a definite change in the individual body, due to some
change in "nurture." There is no secure evidence that any such
individual gain or loss can be transmitted as such, or in any
representative degree. How does this affect our estimate of the value of
"nurture"? How should the sceptical or negative answer, which we believe
to be the scientific one, affect our practice in regard to education,