The Word for World is Forest:

There are many points of satirization in this novel, but the point I want to focus on is the satirizing of inhumanity and murder. As part of their culture and beliefs, the Athsheans take no part in violence and killing - that is, until the increasing threats against their home leave them no other choice than to participate in violent retaliation. Selver is considered a god, in the sense that he introduced them to a new way of life. "And the translator is the god. Selver had brought a new word into the language of his people. He had done a new deed. The word, the deed, the murder. Only a god could lead so great a newcomer as Death across the bridge between the worlds" (page 124). After the big massacre of the yumens, Selver keeps saying "The killing is done, no more killing." What he doesn't understand is that once you cross that threshold, once you have committed murder, there is no going back. There is no cleansing of your soul and no return to the nonviolent, peaceful culture. Lepennon tells Selver this at the end of the novel, "Maybe after I die people will be as they were before I was born, and before you came. But I do not think they will" (page 189). The darkening of one's heart as a result of the greatest wrong that could be committed, murder, cannot be undone, and once a society has been introduced to killing, there is no chance that it will go back to a culture of nonviolence. Selver even explains, "When he has done this, it is done. You cannot take things that exist in the world and try to drive them back into the dream, to hold them inside the dream, with walls and pretenses" (page. 189). The Athsheans are forever altered, they will never be able to return to their peaceful, untainted culture as was before the yumens came, even after the last of the yumens have left; this is because it was they that committed the murder, that killed, regardless of the yumens.