Bring out the contrast between Aram and Mourad in "The Summer of the Beautiful White Horse."

Aram is in awe of his reckless older cousin Mourad. As we see the story through Aram's eyes, one thing that is notable is the combination of the adult viewpoint from which Aram interprets the summer's events and his ability to place himself back into his childish perspective: the story is colored by nostalgia.
Aram presents the family's interpretation of Mourad's behavior as linked to their uncle's wild streak, which they gloss as an innate trait that was passed down to him. Aram, the child, has not yet learned to value his own gifts and envies Mourad and the daring boldness with which he approaches life. Even more, he wishes he could have his cousin's way with animals.
Mourad has a bit more self-awareness than Aram, but it is colored by his extreme self-confidence. Mourad has already learned that even the most outlandish fabrication will be tolerated—if expressed with conviction. Aram's inability to invent stories to justify illegal behavior is symbolically reflected by his inability to ride the "borrowed" horse.

To some extent, Aram are Mourad are foils. In literary terms, a foil is a character who provides a contrast to another character, usually the protagonist. Despite their similar backgrounds, and despite being related by blood, Aram and Mourad have notably different character traits. Aram is quite a shy young man, a bit of a dreamer who suffers from pangs of nostalgia; things were so much better when he was younger. To Aram, the world is full of romance, delightful and dreamy. He's quite naive and easily-led, which makes him the perfect foil to the wild, rebellious Mourad.
Mourad is a much more active, dynamic character than his cousin. Everyone except Aram regards him as stark, staring mad. The general consensus among the tribe is that Mourad has inherited his family's crazy streak from his Uncle Khosrove. Mourad lives up to this reputation by doing wild, crazy things such as stealing horses. Aram wouldn't dream of doing such a thing. (Though he certainly would still dream). Being so easily-led, Aram is happy to go along with Mourad's little games, but it's the forceful, active Mourad who always takes the lead.