One of my absolute favorites is Aldo Leupold
“Ethical behavior is doing the right thing when no one else is watching- even when doing the wrong thing is legal.”
“To those devoid of imagination, a blank place on the map is a useless waste; to others, the most valuable part.”
“Acts of creation are ordinarily reserved for gods and poets, but humbler folk may circumvent this restriction if they know how. To plant a pine, for example, one need be neither god nor poet; one need only own a shovel. By virtue of this curious loophole in the rules, any clodhopper may say: Let there be a tree - and there will be one.”
We reached the old wolf in time to watch a fierce green fire dying in her eyes. I realized then, and have known ever since, that there was something new to me in those eyes - something known only to her and to the mountain. I was young then, and full of trigger-itch; I thought that because fewer wolves meant more deer, that no wolves would mean hunters' paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.…
“Only the most uncritical minds are free from doubt.”