THE SORCERER'S APPRENTICE. By Charles Johnson. Atheneum. 169 pp. $9.95.

THESE EIGHT STORIES, though designed with wit and written with craft, aren't for pleasure cruising. They're stripped models, the vehicles of ideas, built not for acceleration or sweet ride but payload.

Each asserts a philosophical point. Generally, the stories express distrust in ratiocination, free will, "the ooga-booga of Christianity," and Western culture in general. Readers will enjoy the play of Johnson's thought, even while wishing his characters were permitted thoughts, especially dumb ones, of their own.

Most start, like "China," with an appearance of close-grained realism: "Evelyn's problems with her husband, Rudolph, began one evening in early March -- a dreary winter evening in Seattle -- when he complained after a heavy meal of pig's feet and mashed potatoes of shortness of breath."

But soon the characters' diction grows learned, their acts fanciful. Overfed Rudolph, a 54-year-old postman, becomes a mystical warrior of the martial arts. At the end, he appears to gain spiritual ascendance over his church-going, life-denying wife by leaping 20 feet in the air.

In "Alethia," a professor who has been teaching Kant (i.e., cant) has his nose rubbed in life by a sexy young student. First, in a highly plausible scene, she threatens blackmail: either he gives her a B or "I'm gonna have to tell your chairman . . . that you been houndin' me for trim."

Here too, the realistic situation is abandoned, along with colloquial speech. Student virtually abducts professor and takes him on a surreal tour of the seamy side. "The old values are dead," she explains with new- found eloquence. "Our money is paper. Our art is suicide. Our philosophy is a cackle, obscene and touching, from the tower."

Roles have been reversed; it's the professor (and reader) who must learn this story's lesson: that "contemplation of essence, the fundamental approach to Being peculiar to metaphysical knowledge, demands an attitude of loving devotion."

IN FICTION, the figure of the sorcerer customarily stands for that of another conjurer, the writer. So it is in "The Sorcerer's Apprentice," which investigates the origins of creativity. The story's surface is so attenuated that we apprehend the symbolic level without pausing at the literal. Don't place your faith in study, the story advises apprentice writers, nor in reason, nor in models. Just trust the mysterious springs of talent.

Though most of these stories have black protagonists, the author seems interested in black people no more than he is in people. Rather, he tends to treat blackness -- often ingeniously -- as a condition, a state of being, which is already halfway to a metaphor.

In "Popper's Disease," a black physician observes the crash of a flying saucer. Entering the craft to provide medical assistance, he meets a lone alien, resembling "what you might expect to find on a seafood platter in a decent restaurant," dying of an incurable disease.

This disease proves to be, simply, "the Self." It arises from the painful relationship between Self -- that "lonely Leibnizean monad" -- and not-Self.

Dr. Popper suffers from it too, a black (Self) in a white society (not-Self). In this sense, being black is like being an extra-terrestrial -- "It seems we are both strangers here," the alien tells Popper. It all goes back to "the ontogenesis of personality," for "Personality is the product -- no -- the historical creation of society."

A similar determinism informs "The Education of Mingo." The slave Mingo, fresh from Africa, knows nothing -- not even how to laugh -- so Moses Green, his master, sets out to teach him. Soon Moses finds himself actually creating Mingo, "like an artist fingering something fine and noble from a rude chump of foreign clay." The slave learns with frightening speed and spooky completeness, mimicking even his master's limp.

"It's like I just shot out another arm," Moses muses, "and that's Mingo." Or, as Mingo puts it, "When Mingo works, it bees Massa Green workin', right? Bees Massa Green workin', thinkin', doin' through Mingo."

In time, Mingo performs bloody acts that Moses dares not acknowledge as his own desires, though they are. The black man here is not only the white man's creation but also the expression of his darker nature.

Even readers who feel patronized when argument displaces experience, and bored when information drives out feeling, will at the same time be charmed by some of these stories. Often the ideas are nimbly expressed. Sometimes the plots take dramatic turns. Charles Johnson writes so well that one is disposed to patience when he puts down his pen for other tools: his grindstone, his saws.