G.K. Chesterton's first book of essays, The Defendant, contains a short piece entitled "A Defense of Penny Dreadfuls." "Penny dreadful" was the British name for a type of a serialized novel, sold a few chapters at a time in penny-priced issues, and usually dealing with violent, lurid, or horrific subject matter. These stories were controversial among the English upper classes; it was thought that the penny dreadful inspired working-class boys to lives of crime.
Chesterton's defense of penny dreadfuls is occasionally quoted as a defense of "genre fiction" or "adventure stories" in general. In truth, this is a part of the argument, put quite memorably:
People must have conversation, they must have houses, and they must have stories. The simple need for some kind of ideal world in which fictitious persons play an unhampered part is infinitely deeper and older than the rules of good art, and much more important. [...] Literature and fiction are two entirely different things. Literature is a luxury; fiction is a necessity.
[...]
The vast mass of humanity, with their vast mass of idle books and idle words, have never doubted and never will doubt that courage is splendid, that fidelity is noble, that distressed ladies should be rescued, and vanquished enemies spared.
The larger part of Chesterton's argument, though, is a denunciation of class prejudice, albeit in terms that discomfit the democratically-spirited American reader by assuming the gap between the educated and working class, then specifically addressing the educated class as a member of that class:
There is no class of vulgar publications about which there is, to my mind, more utterly ridiculous exaggeration and misconception than the current boys' literature of the lowest stratum. This class of composition has presumably always existed, and must exist. It has no more claim to be good literature than the daily conversation of its readers to be fine oratory, or the lodging-houses and tenements they inhabit to be sublime architecture.
Chesterton assumes that his audience needs no defense of the more literary adventure stories by, say, Walter Scott, or Robert Louis Stevenson. It is noted that Scott and Stevenson have chosen scoundrels for protagonists, without inflicting noticeable moral degradation on their sophisticated audiences. If the non-literary writers fail to provide subtle commentary on human character and motivation, they nevertheless offer archetypical heroes who need no such subtlety:
While the increase of the artistic conscience tends in more ambitious works to brevity and impressionism, voluminous industry still marks the producer of the true romantic trash. There was no end to the ballads of Robin Hood; there is no end to the volumes about Dick Deadshot and the Avenging Nine. These two heroes are deliberately conceived as immortal.
Decades later, at the very end of his career, Chesterton returned to the subject in "Fiction as Food," collected in The Spice of Life. More specifically he returned to his maxim that "literature is a luxury; fiction is a necessity." Having forgotten that he wrote the line in the context of class prejudice and penny dreadfuls, he provided the general argument that fiction, of whatever literary quality, meets basic needs of the human spirit:
Human beings cannot be human without some field of fancy or imagination; some vague idea of the romance of life; and even some holiday of the mind in a romance that is a refuge from life.
What your humble critic calls "genre fiction," Chesterton calls "sensational fiction," and one must admit that Chesterton has the more accurate label. Literary realism is, after all, its own genre. Fantastical stories, or science fiction stories, more often than not appeal to some effect of romance, horror, or sublimity, rather than refined artistic considerations of the particulars of human nature. Chesterton raises the standard of the sensation:
My taste is for the sensational novel, the detective story, the story about death, robbery and secret societies; a taste which I share in common with the bulk at least of the male population of this world. [...] A novel without any death in it is still to me a novel without any life in it. [...] On the whole I think that a tale about one man killing another man is more likely to have something in it than a tale in which, all the characters are talking trivialities without any of that instant and silent presence of death which is one of the strong spiritual bonds of all mankind. I still prefer the novel in which one person does another person to death to the novel in which all the persons are feebly (and vainly) trying to get the others to come to life.
[...]
I believe that sensational novels are the most moral part of modern fiction, and I believe it upon two converging lines, such as make all real conviction. It is, I think, the fact that melodramatic fiction is moral and not immoral. And it is, I think, the abstract truth that any literature that represents our life as dangerous and startling is truer than any literature that represents it as dubious and languid.
Chesterton's defense of sensational literature easily applies to much classic American pulp fiction, but one must wonder how what it makes of the cosmic pessimism of H.P. Lovecraft or Robert E. Howard. Lovecraft portrays human culture and morality as a pragmatic necessity but an objective falsehood: we can only be happy while we remain ignorant of the universe's amoral indifference to us and all that we hold dear. Howard, on the other hand, uses Conan and his other muscle-bound warriors to moralize the fall of Rome, condemning the decadence of all civilization, glorifying instead vitality and physical domination.