be the greatest help in the spread of ideas. The
individual eats a certain food because his neighbor does. Boston
determines to make an effort for a better city because Chicago has
felt the stirrings of civic pride.

A gifted individual with a deep sense of the need of his community
sees an ideal condition, which by his thought becomes a possibility.
These beliefs he shares with a few choice spirits till the circle has
widened. The new ideas come to the notice of the city or the town
officials, new means are adopted of educating the whole community,
and, if necessary, legal measures are passed. But the new means to
betterment must be applied by the individual. Beginning with the
exceptional individual and ending with the average individual, the
perfect circle is rounded out.

The leaders must show convincingly that the laws which they have
discovered may be applied to daily life, but the _individual himself_
must adopt them. When he has been saturated with knowledge, his
inertia will break down, his hopelessness give way to its very
antithesis, a strong hope for a better future. Every known method must
be used by the laboratory to develop this hope into a belief wide
enough to reach all members of every section of the community and deep
enough to become a vital working principle. Only through a belief
strong enough to ride over unbelief and inertia, a belief in the value
of science for personal life strong enough to make a wise choice
possible, can the will to obtain a better environment be developed.
The belief in better things must be thoroughly impressed on the
individual mind. Each individual must understand that it does affect
_him_, that it is _his_ concern, that _he_ must give heed to his
environment. Then he may have the will and make the effort to combat
dangers to body and mind.

Today, belief is much more difficult than ever before because the
dangers are unseen and insidious, and our enemies do not generally
make an appeal through the senses of sight and hearing. But the
dangers to modern life are no less than in the days of the pioneers,
when a stockade was built as a defense from the Indians. We have no
standards for safety. Our enemies are no longer Indians and wild
animals. Those were the days of big things. Today is the day of the
infinitely little. To see our cruelest enemies, we must use the
microscope. Of all our dangers, that of uncleanness leads--uncleanness
of food and water and air--uncleann