Origin and history of unhuman

mid-15c., humain, humaigne, "human," from Old French humain, umain (adj.) "of or belonging to man" (12c.), from Latin humanus "of man, human," also "humane, philanthropic, kind, gentle, polite; learned, refined, civilized." This is in part from PIE *(dh)ghomon-, literally "earthling, earthly being," as opposed to the gods (from root *dhghem- "earth"), but there is no settled explanation of the sound changes involved. Compare Hebrew adam "man," from adamah "ground." Cognate with Old Lithuanian žmuo (accusative žmuni) "man, male person."

Human interest is from 1779. Human rights is attested by 1650s; human being by 1670s.

"Curst with hereditary love of pelf,

"I hate all human beings but myself ;

"Cross and perplex my wife, because she prov'd,

"Poor girl !—not rich enough to be belov'd."

["The Diaboliad, A Poem Dedicated to the Worst Man in His Majesty's Dominions," 1677] 

Human comedy "sum of human activities" translates French comédie humaine (Balzac); see comedy. Human relations is from 1640s as "interaction and connection among persons;" by 1916 as a department in a modern corporation; the phrase had been used from about 1912 in discussions of modern industry.

More than ever, perhaps, the successful manager must be a close student of men and their psychological processes. With the steady rise in intelligence, the increasing complexity of personal relations and the growing tendency of the public to interest themselves in industrial matters, the human element in factory management looms up with increasing importance; and no system of management can be successful that does not take this factor into account. [Dexter S. Kimball, "Principles of Industrial Organization," N.Y., 1913]

 Human resources is attested by 1907, American English, apparently originally among social Christians and based on natural resources. As a personnel management department in a government or corporation by 1977.

prefix of negation, Old English un-, from Proto-Germanic *un- (source also of Old Saxon, Old Frisian, Old High German, German un-, Gothic un-, Dutch on-), from PIE *n- (source of Sanskrit a-, an- "not," Greek a-, an-, Old Irish an-, Latin in-), combining form of PIE root *ne- "not."

The most prolific of English prefixes, freely and widely used in Old English, where it forms more than 1,000 compounds. It disputes with Latin-derived cognate in- (1) the right to form the negation of certain words (indigestable/undigestable, etc.), and though both might be deployed in cooperation to indicate shades of meaning (unfamous/infamous), typically they are not.

Often euphemistic (untruth for "a lie") or emphatic, if there is a sense already of divestment or releasing: unpeel " to peel;" unpick "pick (a lock) with burglars' tools;" unloose for "to loosen."

It also makes words from phrases, such as uncalled-for, c. 1600; undreamed-of, 1630s. Fuller (1661) has unbooklearned. A mid-15c. description of a legal will has unawaydoable; Ben Jonson has un-in-one-breath-utterable. The word uncome-at-able is attested by 1690s in Congreve, frowned at by Samuel Johnson in the 18th century and by Fowler in the 20th ("The word had doubtless, two or three centuries ago, a jolly daredevil hang-the-grammarians air about it ; that has long evaporated ; it serves no purpose that inaccessible does not ....").

But the practice continued; unlawlearned (Bentham, 1810), unlayholdable (1860); unputdownable, of a book, is by 1947; unpindownable, by 1966. Also compare put-up-able-with (1812). As a prefix in telegraphese, to replace not and save the cost of a word, it is attested by 1936.

With the variety of its possible use, and the need for negatives, the number of un- words that might be made in English is almost endless, and that some are used and some never is owing to the caprice of authors.

Dictionary editors noted this since 18c. but also padded the list. John Ash's "New and Complete Dictionary of the English Language" (1775) has many pages of one-line un- entries; among a dozen consecutive entries are unhaggled, unhaired, unhalooed, unhaltering (adj.), unhaltering (n.), which sorts of words OED (1989) notes were "obviously manufactured for the purpose" and some turn up in other texts only decades later, if at all. (Ash vindicated.)