"An ethic, ecologically, is a limitation on freedom of action in the struggle for existence. An ethic, philosophically, is a differentiation of social from anti-social conduct. These are two definitions of one thing. The thing has its origin in the tendency of interdependent individuals or groups to evolve modes of co-operation. The ecologist calls these symbioses. Politics and economics are advanced symbioses in which the original free-for-all competition has been replaced, in part, by co-operative mechanisms with an ethical content."

“The real jewel of my disease-ridden woodlot is the prothonotary warbler. … The flash of his gold-and-blue plumage amid the dank decay of the June woods is in itself proof that dead trees are transmuted into living animals, and vice versa.”

“The ordinary citizen today assumes that science knows what makes the community clock tick; the scientist is equally sure that he does not.”

“What more delightful avocation than to take a piece of land and, by cautious experimentation, to prove how it works? What more substantial service to conservation than to practice it on one's own land?”

“This song of the waters is audible to every ear, but there is other music in these hills, by no means audible to all. To hear even a few notes of it you must first live here for a long time, and you must know the speech of hills and rivers. Then on a still night, when the campfire is low and the Pleiades have climbed over rimrocks, sit quietly and listen for a wolf to howl, and think hard of everything you have seen and tried to understand. Then you may hear it—a vast pulsing harmony—its score inscribed on a thousand hills, its notes the lives and deaths of plants and animals, its rhythms spanning the seconds and the centuries.”

“That land is a community is the basic concept of ecology, but that land is to be loved and respected is an extension of ethics.”

“There are some who can live without wild things, and some who cannot. These essays are the delights and dilemmas of one who cannot.”