The Word for World Is Forest is a science fiction novella by American writer Ursula K. Le Guin, first published in the United States in 1972.

I don’t know. Do men kill men, except in madness? Does any beast kill its own kind? Only the insects. These yumens kill us as lightly as we kill snakes. The one who taught me said that they kill one another, in quarrels, and also in groups, like ants fighting.

“You gave me a gift, the killing of one’s kind, murder. Now, as well as I can, I give you my people’s gift, which is not killing. I think we each find each other’s gift heavy to carry. However, you must carry it alone.”

and yet even so he called the world-time ‘real’ and the dream-time ‘unreal,’ as if that were the difference between them.

I don’t know what ‘human nature’ is. Maybe leaving descriptions of what we wipe out is part of human nature.