The literary philosophy strongly associated with Lovecraft's fiction is Cosmicism.
Cosmicism presents humanity as insignificant within an immense, ancient, and largely indifferent universe. In Lovecraft's stories, terror often comes not from a traditional devil or moral punishment but from discovering that human beings cannot understand—or control—the forces surrounding them.
This idea appears vividly in “The Call of Cthulhu,” where ancient entities and alien influences dwarf human history. The cosmic beings are frequently indifferent rather than conventionally evil, which distinguishes Lovecraft's approach from simpler supernatural horror.
Cosmicism is related to, but not identical with, nihilism. It emphasizes humanity's smallness and vulnerability rather than merely claiming that life has no meaning. Lovecraft also described himself as a cosmic or scientific indifferentist, reflecting his materialist outlook and fascination with astronomy, science, and the limits of human knowledge.