When we thus contemplate the process of social hygiene, we are no longer
in danger of looking upon it as an artificial interference with Nature.
It is in the Book of Nature, as Campanella put it, that the laws of
life and of government are to be read. Or, as Quesnel said two centuries
ago, more precisely for our present purpose, "Nature is universal
hygiene." All animals are scrupulous in hygiene; the elaboration of
hygiene moves _pari passu_ with the rank of a species in intelligence.
Even the cockroach, which lives on what we call filth, spends the
greater part of its time in the cultivation of personal cleanliness. And
all social hygiene, in its fullest sense, is but an increasingly complex
and extended method of purification--the purification of the conditions
of life by sound legislation, the purification of our own minds by
better knowledge, the purification of our hearts by a growing sense of
responsibility, the purification of the race itself by an enlightened
eugenics, consciously aiding Nature in her manifest effort to embody new
ideals of life. It was not Man, but Nature, who realized the daring and
splendid idea--risky as it was--of placing the higher anthropoids on
their hind limbs and so liberating their fore-limbs in the service of
their nimble and aspiring brains. We may humbly follow in the same path,
liberating latent forces of life and suppressing those which no longer
serve the present ends of life. For, as Shakespeare said, when in _The
Winter's Tale_ he set forth a luminous philosophy of social hygiene and
applied it to eugenics,

"Nature is made better by no mean
But Nature makes that mean ...
This is an art
Which does mend Nature, change it rather, but
The art itself is Nature."

In whatever way it may be understood, however, social hygiene is now very
much to the front of people's minds. The present volume, I wish to make
clear, has not been hastily written to meet any real or supposed demand.
It has slowly grown during a period of nearly twenty-five years, and it
expresses an attitude which is implicit or explicit in the whole of my
work. By some readers, doubtless, it will be seen to constitute an
extension in various directions of the arguments developed in the larger
work on "Sex in Relation to Society," which is the final volume of my
_Studies in the Psychology of Sex_. The book I now bring forward may,
however, be more properly regarded as