“I would not sacrifice a single living mesquite tree for any book ever written. One square mile of living desert is worth a hundred 'great books' - and one brave deed is worth a thousand.”
“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.”
“What we need now are heroes and heroines, about a million of them, one brave deed is worth a thousand books. Sentiment without action is the ruin of the soul.”
“One book, printed in the Heart's own wax / Is worth a thousand in the stack's”
“Any experiment that can benefit by one hairsbreadth any single human life is a thousand times worth trying.”
“I think it is far more important to save one square mile of wilderness, anywhere, by any means, than to produce another book on the subject.”