nowledge goes the responsibility and duty of applying it in
defense of society and civilization.

This book is a sincere effort, first, to supply the needed knowledge of
terrible wrongs and destructions; and, secondly, to indicate cautiously
and tentatively the most available means of attacking the evils described.
It is an attempt to enlighten public opinion on one of the gravest of
modern problems--indeed, the very gravest, with the exception of the
warfare between capital and labor. The book is not intended for children,
or even for adolescents, but rather for parents, teachers, and ministers
who have to answer the questions of children and youth about sex
relations, or deal sympathetically with the victims of sexual vice.

All efforts to deal directly with sex relations in schools, churches, and
clubs are hampered, and must be for some years to come, by the lack of
competent instructors in that difficult subject. So far as instruction in
educational institutions is concerned, it seems as if the normal schools
and the colleges for men or for women must be selected for the first
experiments on class instruction. Family instruction is in most cases
impossible; because neither father nor mother is competent to teach the
children what needs to be taught about both the normal and the disordered
sex relations. The ministers and priests are as a rule equally
incompetent. They can give precepts or orders, but not explanations or
reasons. Considerate managers of large industries ought to have a keen
interest in all social hygiene problems, because they nearly concern
industrial efficiency; but it is only lately that business men have begun
to understand the close connection between public health and industrial
prosperity, and most of them are not well informed on the subject.

Against prostitution and drunkenness governments of many sorts have been
struggling ineffectually for centuries. These two evils go together; but
whether taken separately or together no government has yet adopted an
effective mode of dealing with them. Fortunately medical science has
lately placed in the hands of government, and of private associations,
effective means of defense against the social vices and their
consequences; and the new social ethics call loudly on all men of good
will to enlist in the warfare against these ancient evils, which to-day
are more destructive than ever before, because of the prevailing
industrial and social freedom, and