The first science-fiction novel by H. G. Wells, describing a journey into the world of the future inhabited by two kinds of creatures: the Morlocks, who live in an underground world and tend to machines, and the fragile Eloi, who are completely unsuited for labor.
Over thousands of years, both have practically lost their reason, becoming half-animals.
“…In earlier times, the dwellers of the Upper World were a privileged class, and the Morlocks their working servants; but that was long ago—gone into the past… The Eloi have degenerated into beautiful, worthless trifles. They still hold the surface of the earth by grace… but the relentless Nemesis was quietly drawing near to the pampered happy ones. Many centuries ago man deprived his neighbor of happiness and sunlight. And now that neighbor has become utterly unrecognizable! The Eloi have received again the first lesson of life. They have learned fear anew…”