at natural law
promises to those who obey it.

By using numerous tests which have been suggested in preceding chapters
we can learn how far we and our communities obey natural law when
working and playing. Health for health's sake has nowhere been urged.
On the contrary, healthful living has been frankly valued for its aid
to efficient living by individual and by community; wherefore the
emphasis upon others' health and upon the civic aspects of our own
health. Tests furnish us with the technic necessary to efficient
living; civics, with the larger reason; natural law, with the "pillar
of fire by night" to help us choose our path among habits and pleasures
whose immediate results upon efficient living cannot easily be
determined.

Fashions, tastes, mannerisms, personal indulgences, have been left for
Agassiz to deal with. Generally speaking, we all know of numerous acts
committed and numerous acts omitted in our daily routine that convict
us of not living up to our knowledge of physiology and hygiene,--wearing
tight shoes or tight corsets, drinking strong coffee, smoking, reading
while reclining, failing to insure clean air and clean bodies. Then
there are other acts whose omission or commission violate no physical
law so far as we can see, but whose unnaturalness we concede,--putting
chalk on the eyebrows, wearing false hair or curious puffs, putting
perfumery in the bath or on handkerchiefs, assuming artificial poses of
body or mouth. These violations of natural law are forced upon us by
"style" or "custom" or family convenience. When we come to choose
between following fashions and disobeying them, we generally decide that
it is better to do a foolish or slightly harmful thing than to occasion
criticism, mirth, or even special notice by our dress or our
abstemiousness.

Last night I went to a dinner party at eight. I ate and ate a great
variety of palatable foods that Nature Back never knew. After two hours
of eating I imbibed for two hours the tobacco smoke of the gentlemen
who made up the party. I knew that eight o'clock was too late for me to
begin eating, that two hours was too long to eat, that the tobacco of
others was bad for my health and for to-day's efficiency. All this I
knew when I accepted the invitation to dinner. I went with no intention
of preventing others from smoking or of lecturing my host or his chef
or his guests for the unhygienic practices of our day. Yet the physical
ills were more than o