I think everyone expected to see a man emerge—possibly something a little unlike us terrestrial men, but in all essentials a man.
He pointed out—writing in a foolish, facetious tone—that the perfection of mechanical appliances must ultimately supersede limbs; the perfection of chemical devices, digestion; that such organs as hair, external nose, teeth, ears, and chin were no longer essential parts of the human being, and that the tendency of natural selection would lie in the direction of their steady diminution through the coming ages.
There are no more uses of "essential" in the book.
Show samples from other sources
The essential feature of the pen is that it writes so consistently.
I carry all the essential tools and materials I need in this toolbox.