Andre Norton. Magic lavender green (№ 167881)

... In this wide world so much that you never finish to learn. And goodness the earth gives so much, that man could not. A man takes and does not give thanks. He doesn't believe the truth - that man must be one with all that grows and that runs, even with the four-legged, and with the fact that spreads its wings and lives in the sky. People kill without thinking, digging and tearing no sense, don't appreciate the great gifts. But let cherish or it will turn against them.