Europe is overpopulated, the world will soon be in the same condition, and if the self-reproduction of man is not rationalized... we shall have war.

Governments always commit their entire populations when the demands grow heavy enough. By their passive acceptance, these populations become accessories to whatever is done in their name.

‎Using his burgeoning intelligence, this most successful of all mammals has exploited the environment to produce food for an ever increasing population. Instead of controlling the environment for the benefit of the population, perhaps it's time we controlled the population to allow the survival of the environment.

It is obvious that the best qualities in man must atrophy in a standing-room-only environment.

We have been God-like in our planned breeding of our domesticated plants and animals, but we have been rabbit-like in our unplanned breeding of ourselves.

If people waited to know one another before they married, the world wouldn't be so grossly over-populated as it is now.

Creation destroys as it goes, throws down one tree for the rise of another. But ideal mankind would abolish death, multiply itself million upon million, rear up city upon city, save every parasite alive, until the accumulation of mere existence is swollen to a horror.

Over-population is a phenomenon connected with the survival of the unfit, and it is a mechanism which has created conditions favourable to the survival of the unfit and the elimination of the fit.

All that tread The globe are but a handful to the tribes That slumber in its bosom.