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

The exquisite sight, sound, and smell of wilderness is many times more powerful if it is earned through physical achievement, if it comes at the end of a long and fatiguing trip for which vigorous good health is necessary. Practically speaking, this means that no one should be able to enter a wilderness by mechanical means.

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

You cannot do only one thing.

Moreover, the practical recommendations deduced from ecological principles threaten the vested interests of commerce; it is hardly surprising that the financial and political power created by these investments should be used sometimes to suppress environmental impact studies.

However, I think the major opposition to ecology has deeper roots than mere economics; ecology threatens widely held values so fundamental that they must be called religious.

Ecological differentiation is the necessary condition for coexistence.