Iconic science fiction author Philip K. Dick penned numerous novels in the 1960s and 1970s. His earlier work—including such notable titles as The Man in the High Castle (1963 Hugo Award), Do Androids Dream of Electric Sheep (the basis for the 1982 film Blade Runner), and Ubik—was more traditional sci-fi/speculative fiction. However, the 1970s marked a transition in his writing. After dabbling in the early 1970s Southern California drug scene, Dick experienced a spiritual epiphany, and his writing began to focus on metaphysical and theological topics. Many of those issues appear in A Scanner Darkly. Characters ponder The Nature of Reality, which, according to Dick, is all a matter of perception. Arctor undergoes a metaphysical crisis when he loses touch with his sense of self. A passage from Goethe’s Faust is cited evoking God as a beacon in an existential wilderness. Dick explored these issues in his subsequent writing—most deeply in his 1981 novel Valis—as he struggled to process his revelation.

Part of that revelation, one which thematically dominates the narrative, is the potentially destructive nature of recreational drugs. Early in his career, Dick wrote many of his novels while under the influence of amphetamines.