Edward Abbey said this quote

A man could be a lover and defender of the wilderness without ever in his lifetime leaving the boundaries of asphalt, powerlines, and right-angled surfaces. We need wilderness whether or not we ever set foot in it. We need a refuge even though we may never need to set foot in it. We need the possibility of escape as surely as we need hope; without it the life of the cities would drive all men into crime or drugs or psychoanalysis.

~ Edward Abbey

Philosophy without action is the ruin of the soul. One brave deed is worth a hundred books, a thousand theories, a million words. Now as always we need heroes. And heroines! Down with the passive and the limp.

~ Edward Abbey

But it is a writer's duty to write and speak and record the truth, always the truth, no matter whom may be offended.

~ Edward Abbey

The novel should tell the truth, as I see the truth, or as the novelist persuades me to see it. And one more demand: I expect the novelist to aspire to improve the world. ... As a novelist, I want to be more than one more dog barking at the other dogs barking at me. Not out of any foolish hope that one novelist, or all virtuous novelists in chorus, can make much of a difference for good, except in the long run, but out of the need to prevent the human world from relaxing into something worse. To maintain the tension between truth and falsity, beauty and ugliness, good and evil. ... I believe the highest duty of the serious novelist is, whatever the means or technique, to be a critic of his society, to hold society to its own ideals, or if these ideals are unworthy, to suggest better ideals.

~ Edward Abbey