In a finite world this means that the per capita share of the world's goods must steadily decrease.

The essence of dramatic tragedy is not unhappiness. It resides in the solemnity of the remorseless working of things.

No one should be able to enter a wilderness by mechanical means.

It takes five years for a willing person's mind to change. Have patience with yourself and others when treading in an area protected by a taboo.

The only thing we can really count on in this uncertain world is human unreliability itself.

It is a mistake to think that we can control the breeding of mankind in the long run by an appeal to conscience.

The Universal Declaration of Human Rights describes the family as the natural and fundamental unit of society. It follows that any choice and decision with regard to the size of the family must irrevocably rest with the family itself, and cannot be made by anyone else.