The modern conception of the words 'human' and 'civilized' don't accurately reflect the socio-political construct which gave rise to those terms. This ambiguity plays out in other words which represent ideas relating to social identity and security. In a slightly wider context it is the reason for Operation Gladio, a kind of cultural paranoia built upon a fraudulent protection model.
"Everybody knows that the human race is the dominant form of life on this planet."
But wait, did you see what I did there? Did you notice the fallacy that implies that you in error if you don't identify as human? I'm not talking about aliens or insects, this discussion is about people who look like humans but do not subscribe to the human condition.
By now you're probably thinking WTF is he talking about?, so I should describe the origins of humanism and how it come to be that it was considered to be a universal state of being within society.
Above all: "appellari ceteros homines, esse solos eos, qui essent politi propriis humanitatis artibus" (De re publica I, xvii, 28). "Thus, not all men are humani or demonstrate humanitas. Only in the civilization of the Roman Empire and its social order does humanitas count as an educational value and socio-ethical virtue. Those who live outside the Empire are not yet fully 'human,' they are 'barbarians'."
What is being described here is the distinction made by Cicero and others which classified people as either homo humanus or homo barbarus, human or barbarian. Rome adopted Christianity as the official religion of the state, and thus the Roman Catholic Church formed an unholy alliance with the Roman body politic. By applying the religious title as a descriptive name, we get the universal church of Rome, since Katholika, from Catholic means universal or general.
catholic (adj.) mid-14c., "of the doctrines of the ancient Church," literally "universally accepted," from French catholique, from Church Latin catholicus "universal, general," from Greek katholikos, from phrase kath' holou "on the whole, in general," from kata "about" + genitive of holos "whole" (see safe (adj.)). Applied to the Church in Rome c. 1554, after the Reformation began. General sense of "of interest to all, universal" is from 1550s.
So there you have it. Humans are people who belong to the Roman security model who believe that all people are human. Other people are not necessarily barbaric, but cultural supposition of humanism implies a distrust of those who do not conform to the norms of human society.
Legal distinction between men and humans:
person: A man considered according to the rank he holds in society, with all the rights to which the place he holds entitles him, and the duties which it imposes. 1 Bouv. Inst. no. 137. A human being considered as capable of having rights and or being charged with duties, while a "thing" is the object over which rights may be exercised.
Black's 2nd (1910)
Humans as monsters:
human being See MONSTER.
Ballentine's Law Dictionary (1930)