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

Economists (and others) who are satisfied with nature-free equations develop a dangerous hubris about the potency of our species

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

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.

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

Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons.

We see only what we have names for.