From the February 2009 Idaho Observer:
Are we not human? By Don Harkins Yes, we are not human.
I then consulted a dictionary of word origins and was amazed at what I found. "Human" traces back to the Latin "homunculus" (the root word for "uncle") or "homo" (man); the adjective form of which is "humanus" which gives us "human" and "humanity" and "humane." All that goes back to 12th century English and it was not until the 17th century that the term "being" was attached to "human" as a description of Man (probably for legal purposes).
So, while Maxwell was not correct entymologically, he was right grammatically. "Human" is not a noun, it is an adjective and it requires "being" (an adverb) to give us a phrase in common usage that connotes pure fiction—nothing else.
In the Ringing Cedars series, the heroine Anastasia refers to us collectively and individually as "Man" with a capital M. I think this is the proper term for us unless we need to be gender specific. When gender specificity is required, the female gender of Man can be specified as "woman." The most likely origin of "woman" is Old English from "womb-man."