Charlton Heston and a savagely coiffed vixen, wrapped in animal skins, riding horseback along a desolate seashore, confronted by the spike-crowned ruin of the Statue of Liberty half buried in the sand: everyone knows how the world ends. First radiation, plague, an asteroid, or some other cataclysm kills most of humankind. The remnants mutate, lapse into feudalism, or revert to prehistoric brutality. Old cults are revived with their knives and brutal gods, while tiny noble bands cling to the tatters of the lost civilization, preserving knowledge of machinery, agriculture, and the missionary position against some future renascence, and confronting their ancestors’ legacy of greatness and destruction.
Ambivalence toward technology is the underlying theme, and thus we are accustomed to thinking of stories that depict the end of the world and its aftermath as essentially science fiction. These stories feel like science fiction, too, because typically they deal with the changed nature of society in the wake of cataclysm, the strange new priesthoods, the caste systems of the genetically stable, the worshipers of techno-death, the rigid pastoral theocracies in which mutants and machinery are taboo, etc.; for inevitably these new societies mirror and comment upon our own. Science fiction has always been a powerful instrument of satire, and thus it is often the satirist’s finger that pushes the button, or releases the killer bug.
This may help to explain why the post-apocalyptic mode has long attracted writers not generally considered part of the science fiction tradition. It’s one of the few subgenres of science fiction, along with stories of the near future (also friendly to satirists), that may be safely attempted by a mainstream writer without incurring too much damage to his or her credentials for seriousness. The anti–science fiction prejudice among some readers and writers is so strong that in reviewing a work of science fiction by a mainstream author a charitable critic will often turn to words such as “parable” or “fable” to warm the author’s bathwater a little, and it is an established fact that a preponderance of religious imagery or an avowed religious intent can go a long way toward mitigating the science-fictional taint, which also helps explain the appeal to mainstream writers such as Walker Percy of the post-apocalyptic story, whose themes of annihilation and re-creation are so easily indexed both to the last book of the New Testament and the first book of the Old. It’s hard to imagine the author of Love in the Ruins writing a space opera.
There is also a strong current of conventional hard-edged naturalism at work in much post-apocalyptic science fiction that may further serve to draw and to reassure the mainstream writer. If the destruction is sufficiently great, life and its appurtenances are reduced to a finite set, mitigating the demand for baroque inventiveness imposed by other kinds of science fiction, while the extreme state of the natural world—global ice, global goo, global ocean—serves to reflect the extremes of human psychology …