an Life]

The combined effects of all the unhygienic modes of living are
undoubtedly greatly to shorten human life. Most other mammals live about
five times the growing period. In man, this would mean that the normal
life-span should be about a century and a quarter, an age which is now
reached only in one case out of millions.

[Sidenote: No Return to Nature]

Yet it would be foolish, even if it were possible, to attempt a complete
"return to Nature" by abolishing all the ways and conventions of
civilization. This would be throwing away our social inheritance and
returning to barbarism. We must go forward, not backward. Just as the
cure for the evils of Democracy is said to be more Democracy; so the
cure for the evils of civilization must be more civilization. The
equilibrium of Nature having been upset by civilization, science, one of
the great products of civilization, must now work out the remedies. Just
as the waste of the soil which civilization has brought is to be
compensated by that great product of civilization, scientific
agriculture, so the waste of vital resources is to be compensated by
scientific hygiene. The saving of civilization depends on following not
those who repudiate it, like Thoreau, but those who make use of it, like
Pasteur. What the world needs is not to abolish houses, but to ventilate
them; not to go naked, but to devise better clothes, which have all the
advantages and none of the disadvantages of those we now wear; not to
return to the diet of the anthropoid apes, but to remodel that which we
have; not to give up chairs, but to improve the form of chairs; not to
abandon reading, but to employ corrective eyeglasses and clear printing;
not to abrogate division of labor, but to shorten the hours of labor and
provide wholesome recreations and special compensating advantages when
needed. When, in future centuries, these come to be reckoned among the
great triumphs of civilization, we may expect human life to be longer
and perhaps stronger than in any primitive state of Nature, just as
where modern scientific forestry has been applied we find longer lived
and better trees than ever grew in Nature's jungles.

Section VI--The Fields of Hygiene

[Sidenote: Public Versus Individual Hygiene]

The object of this book is primarily to instruct the individual as to
what he can do to maintain his own individual health. But individual
hygiene is only one particular branch of hygiene, and it is wel