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 three filters [against folly] operate through these particular questions: Literacy: What are the words? Numeracy: What are the numbers? Ecolacy: And then what?

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

Value is a relative concept: the value of each action is determined by comparing it with other possible actions.

Continuity is at the heart of conservatism: ecology serves that heart.

You cannot do only one thing.

A finite world can support only a finite population; therefore, population growth must eventually equal zero.