The moral of a story profits from being tacked on at the end; nobody wants it halfway through. A careful disregard for anything that resembles preachiness marks many a good morality tale, from Robin Hood on. Good adventure stories capture a childlike intuition that adults can also buy into. Bad ones dump foregone adult conclusions into a landscape of wishful thinking.

Louis de Bernieres and David Mitchell have both written woefully over serious novels; both deal in tropical islands, bandits, and magic; and both are extremely long. Mr. de Bernieres is an Englishman who began his career writing magical realist novels set in Colombia, where he taught for a few years. “Birds without Wings” (Alfred A. Knopf, 553 pages, $25.95) magicalizes a few bits of Turkish folk life, but the floridness of Mr. de Bernieres’s Colombian period has mellowed into a general taste for quaint peoples and their vaguely exotic misadventures.

“Birds Without Wings” pairs life in a Turkish village during the early 19th century with the rise of Mustafa Kemal Ataturk. It champions the droll villagers of Eskibahce – Christians and Muslims who share gossip and develop crushes on one another. Mr. de Bernieres writes in a cliched peasant diction, resisting contractions and using “pleased by” instead of “likes,” “wish” instead of “want,” “sorrow” instead of “trouble.” The prose seems so convinced that it is not English that it sometimes ventures sophisticated ESL malapropisms: “Nonetheless, the habit of hacking extra rooms out of the rock also pertained in these buildings.” Does he mean “obtained”?

More maddeningly, this novel is made of ever-expanding fairy-tale sentences, in which traditions, events, and superstitions are introduced afresh and explained ad nauseum, as if Mr. de Bernieres were being paid by the line, as if mythicness, not myth, were the point:

suddenly I took fright, because I heard a
noise and I thought it might be Markala or
some other demon because they like deserted
spots, but it was only Ibrahim, and I sat down
on a rock because I’d been so frightened in
case it was the demon, and I had demons on my
mind because it was only the day after
epiphany and we’d just burned Siphotis to get
rid of the evil and filth.

The impression that Mr. de Bernieres is just making things up as he goes along is reinforced by his repetition and the skimpiness of his overall plot. Events are constantly retold by different characters with similar voices (to imitate oral tradition), again by a third-person narrator when expedient, and sometimes by the same character (to imitate narrative sweep).

Mr. de Bernieres’s unsatisfying methods may be overlooked by fans of his previous novel, “Captain Corelli’s Mandolin,” not least because the real point of “Birds Without Wings” is the post-September 11 piety among intellectuals that religion is the root of all evil. As nationalism fosters fundamentalism, the village’s Christians are exiled, and Muslim fathers turn on their daughters.

Mr. de Bernieres pompously complains that “the primary epiphenomena of any religion’s foundation are the production and flourishment of hypocrisy, megalomania, and psychopathy, and the first casualties of a religion’s establishment are the intentions of its founder.” This is too spine-tingling, these “epiphenomena” accrue too many successful movements besides religions, and “flourishment” is not a word. If Mr. de Bernieres were not so permissive with himself and his language, he might not have written such a dull and patronizing book.

***

Mr. Mitchell’s “Cloud Atlas” (Random House, 509 pages, $14.95) is corrupted by a similar high-mindedness. Mr. Mitchell has written six interrelated stories in which the hero is somehow oppressed, achieves a pyrrhic freedom, and leaves behind some document of his struggle. This is found by the hero of the next story, who mentions it in his or her own document.

Mr. Mitchell also has contrived to distract each character at a climactic moment of his story. Then, at the end of the sixth story, the sixth narrator picks up the fifth story where it left off, and so on, making for one of the most hard-won denouements in literary history. It is certainly more trouble than it is worth.

The stories take place in successive futures, beginning in the 19th century, so that they constitute an alternative universe. Indeed, “Cloud Atlas” is a novel indebted to one of the more sentimental conceits of science fiction: namely, that our civilization, though it may be destroyed, can persist in texts kept by outlaw bands who may revive it when the succeeding civilization dies out. This is the premise of Bradbury’s “Fahrenheit 451,” Asimov’s “Foundation,” even “Star Wars.”

But “Cloud Atlas” is published as literary fiction: Because there are six not-necessarily-true messages in a bottle rather than one story about a message in a bottle, it is unsatisfying in a seemingly daring and impressive way. It aspires to the wizardry of the Oulipo group, who invented arbitrary rules like not using the letter “e” in a novel. But Oulipo thought its rules were more interesting that the resultant text, and Mr. Mitchell’s resultant text is certainly a case in point.

Mr. Mitchell treats his stories like chopped liver. To serve his conceit, he will interrupt a somewhat charming epistolary adventure narrated by a haughty young composer in Belgium to introduce a made-for-TV potboiler about an intrepid reporter and some nuclear secrets. Turning the page of an Orwellian robot story to find the sentence “Old Georgie’s path an’ mine crossed more times’n I’m comfy mem’ryin’ ” – the start of a new story – is one of the most dispiriting experiences I have had in my reading life.

Mr. Mitchell might like to be David Foster Wallace; “Cloud Atlas” would like to be “Infinite Jest.” But it has more in common with the bland piety of Ayn Rand’s “Anthem.” Mr. Mitchell, like Mr. de Bernieres, makes his idealism superior to his material – silly priests in the former case, impossible apocalyptic robots in the latter. It is quite grown-up of them.