Cthulhu Mythos

The Cthulhu Mythos is a shared fictional universe, based on the work of American horror writer H. P. Lovecraft.

The term was first coined by August Derleth, a contemporary correspondent of Lovecraft, who used the name of the creature Cthulhu — a central figure in Lovecraft literature and the focus of Lovecraft's short story "The Call of Cthulhu" (first published in pulp magazine Weird Tales in 1928) — to identify the system of lore employed by Lovecraft and his literary successors. The writer Richard L. Tierney later applied the term "Derleth Mythos" to distinguish between Lovecraft's works and Derleth's later stories.

Authors of Lovecraftian horror use elements of the Mythos in an ongoing expansion of the fictional universe.

In his essay "H. P. Lovecraft and the Cthulhu Mythos", Robert M. Price described two stages in the development of the Cthulhu Mythos. Price called the first stage the "Cthulhu Mythos proper." This stage was formulated during Lovecraft's lifetime and was subject to his guidance. The second stage was guided by August Derleth who, in addition to publishing Lovecraft's stories after his death, attempted to categorize and expand the Mythos.

An ongoing theme in Lovecraft's work is the complete irrelevance of mankind in the face of the cosmic horrors that apparently exist in the universe. Lovecraft made frequent reference to the "Great Old Ones": a loose pantheon of ancient, powerful deities from space who once ruled the Earth and who have since fallen into a deathlike sleep. This was first established in "The Call of Cthulhu", in which the minds of the human characters deteriorated when afforded a glimpse of what exists outside their perceived reality. Lovecraft emphasized the point by stating in the opening sentence of the story that "The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents."

Writer Dirk W. Mosig notes that Lovecraft was a "mechanistic materialist" who embraced the philosophy of cosmic indifferentism. Lovecraft believed in a purposeless, mechanical, and uncaring universe. Human beings, with their limited faculties, could never fully understand this universe, and the cognitive dissonance caused by limitation leads to insanity. Lovecraft's viewpoint made no allowance for religious belief which could not be supported scientifically, with the incomprehensible, cosmic forces of his tales having as little regard for humanity as humans have for insects.

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