"The mortal enemies of man are not his fellows of another continent or race; they are the aspects of the physical world which limit or challenge his control, the disease germs that attack him and his domesticated plants and animals, and the insects that carry many of these germs as well as working notable direct injury. This is not the age of man, however great his superiority in size and intelligence; it is literally the age of insects." – W. C. Allee
- Simple: The human enemy of people is not other people from other countries or races. They are the form of the real world which limit or test his control, the disease germs that attack him and other plants and animals, and the insects that carry a lot of these germs as well as causing direct injury. This is not the people's period, no matter how great his power in size and mind. It is really the age of insects.