the process of evolution
adapted. In the light of these conditions men have found
that if they are to live happily and fruitfully together, certain
original tendencies must be stimulated and developed, others
weakened, redirected, and modified, and still others, within
limits possibly, altogether repressed. Individuals display at
once curiosity and fear, pity and pugnacity, acquisitiveness
and sympathy. Some of these it has been found useful to
allow free play; others, even if moderately indulged, may
bring injury to the individual and the group in which his own
life is involved. Education, public opinion, and law are
more or less deliberate methods society has provided for the
stimulation and repression of specific instinctive tendencies.
Curiosity and sympathy are valued and encouraged because
they contribute, respectively, to science and to cooeperation;
pugnacity and acquisitiveness must be kept in check if people
are not simply to live, but to live together happily.

But the substitution of control for caprice in the living-out
of our native possibilities is as difficult as it is imperative. As
already noted, instincts are imperious driving forces as well
as mechanisms. While we can modify and redirect our native
tendencies of fear, curiosity, pugnacity, and the like, they
remain as strong currents of human behavior. They can be
turned into new channels; they cannot simply be blocked.
Indeed, in some cases, it is clearly the social environment that
needs to be modified rather than human behavior. Though
it be juvenile delinquency for a boy to play baseball on a
crowded street, it is not because there is intrinsically anything
unwholesome or harmful in play. What is clearly demanded
is not a crushing of the play instinct, but better facilities
for its expression. A boy's native sociability and gift for
leadership may make him, for want of a better opportunity, a
gangster. But to cut off those impulses altogether would be
to cut off the sources of good citizenship. The settlement
clubs or the Boy Scout organizations in our large cities are
instances of what may be accomplished in the way of providing
a social environment in which native desires can be freely and
fruitfully fulfilled.

Social conditions can thus be modified so as to give satisfaction
to a larger proportion of natural desires. On the other
hand, civilization in the twentieth century remains so divergent
from the mode of life to which man's inbor