"The Horla" by Guy De Maupassant

From:  Library of the World's Best Mystery and Detective Stories 

edited by Julian Hawthorne (a public domain book).

Great horror story.  A double takes over our narrator's life (story is told as a journal).  The double, who seems to live on milk and bread, controls our narrator's thoughts, but also makes our narrator wonderfully speculative on the nature of life.

"Whence do these mysterious influences come, which change our happiness into discouragement, and our self-confidence into diffidence. One might almost say that the air, the invisible air is full of unknowable Forces, whose mysterious presence we have to endure." p. 40

"Last night I felt someone leaning on me who was sucking my life from between my lips with his mouth.  Yes, he was sucking it out of my neck like a leech would have done." 44

The stars dart out their rays in the dark heavens.  Who inhabits those worlds? What forms, what living being are there yonder.  What do those who are thinkers in those distant worlds know more than we do?

"Our (bodies) are so weak, so awkwardly conceived, encumbered with organs that are always tired, always on the strain like locks that are too complicated . . . an animal machine which is a prey to maladies, to malformations, to decay; broken-winded, badly regulated,  . . . a coarse and a delicate work." 57