Literary devices in "Stability" by Philip K. Dick include personification, vivid imagery, oxymoron, metaphor, simile, interruption, and euphemism. Let's look at an example of each of these and then talk about how they impact the story.
Personification occurs as the night swallows up the...
flying Benton. Night is given a human characteristic here. Vivid imagery is strong during the flight but also in Benton's travel through time. Oxymoron is present in the phrase "frantic joy." Joy generally does not suggest something frantic, yet the combination of the two words gives this joy a sinister tinge.
Metaphor is apparent in the "black bowl" in which Benton flies. This means the sky, of course, and it is also described as having an "invisible floor." In similes, Benton aims "like an arrow," and the people in the offices work together "like a great symphony orchestra." The second simile is expanded a bit in a speculation of what would happen if one person were "off key" or "out of time."
The author uses interruption when the narrator interrupts himself and leaves a sentence hanging as he does when the Controller is reflecting to himself and when the narrator hints at what might happen if someone is seen as upsetting the Stability. He doesn't say what will happen to that person, but readers can certainly guess. The Cart will come for that person. The Cart is a euphemism for death—actually, murder.
All of these literary devices enhance the interest of the story. They draw readers in and hold their attention. They also make the story's primary theme (that of a controlled society under threat from an outside force) all the more vivid. They raise tension (as in the interruptions). They set the scene and help readers understand the characters. Then even add notes of fear (as with the Cart). Indeed, the author uses these literary devices to fine effect.