A fascinating philosophical structure thought up by Orson Scott Card
for the Ender
series of Sci-Fi novels. The hierarchy
describes how humans can possibly come to comprehend and interact with an alien culture
"...Demosthenes' History of Wutan in Trondheim...The Nordic language recognizes four orders of foreignness. The first is the otherlander, or utlanning, the stranger that we recognize as being a human of our world, but of another city or country. The second is the framling... This is the stranger that we recognize as human, but of another world. The third is the raman, the stranger that we recognize as human, but of another species. The fourth is the true alien, the varelse, which includes all the animals, for with them no conversation is possible. They live, but we cannot guess what purposes or causes make them act. They might be intelligent, they might be self-aware, but we cannot know it. "
Orson Scott Card, Speaker for the Dead.
New York: Tor (1986)
Note that here "human" really means "comprehensibly sentient," much like how on Star Trek all of the Federation gets mushed into "humanity." Also note for the purposes of the story "Demosthenes' History of Wutan in Trondheim" was invented by Card. In the story it was a classic work written by Ender's sister Valentine Wiggin under her pseudonym Demosthenes.
"So you thought up the hierarchy of alienness. Utlannings are strangers from our own world. Framlings are strangers of our own species, but from another world. Ramen are strangers of another species, but capable of communication with us, capable of co-existence with humanity. Last are varelse -- and what are they?"
"The pequeninos are not varelse. Neither is the hive queen."
"But the descolada is. Varelse. An alien life form that's capable of destroying all of humanity ..."
"Unless we can tame it ..."
"... Yet which we cannot possibly communicate with, an alien species that we cannot live with. You're the one who said that in that case war is unavoidable. If an alien species seems bent on destroying us and we can't communicate with them, can't understand them, if there's no possibility of turning them away from their course peacefully, then we are justified in any action necessary to save ourselves, including the complete destruction of the other species."
--Orson Scott Card, Xenocide
In "Speaker for the Dead," There is also an allusion to a fifth alien, a monstrous fearsome murderer.
"You're afraid of the stranger, whether he's utlanning or framling. When you think of him killing a man that you know of and value, then it doesn't matter what his shape is. He's varelse then, or worse--djur, the dire beast, that comes in the night with slavering jaws. If you had the only gun in your village, and the beasts that had torn apart one of your people were coming again, would you stop to ask if they also had a right to live, or would you act to save your village, the people that you knew, the people who depended on you?"