In John Knowles's A Separate Peace, Brinker is the "big man on campus":
Brinker looked the standard preparatory school article his gray gabardine suit with square, handsewn-looking jacket pockets, a conservative necktie, and dark brown cordovan shoes. His face was all straight lines--eyebrows, mouth, nose, everything--and he carried his six feet of height straight as well. He looked but happened not to be athletic, being too busy with politics, arrangements, and offices.
There was nothing idiosyncratic about Brinker unless you saw him from behind; I did as he turned to close the door after him. The flaps of his big gabardine jacket parted slightly over his healthy rump, and it is that, without any sense of derision at all, that I recall as Brinker's salient characteristic, those healthy, determined, not over-exaggerated but defined and substantial buttocks. [The implication here cannot be missed as Brinker than takes Gene to the Butt Room in Chapter 7.]
Brinker treats Gene like a prisoner when he takes him to the Butt Room:
"Here's your prisoner, gentlemen," announced Brinker, seizing my neck and pushing me..."I'm turning him over to the proper authorities."
In Chapters 7 and 11, the reader will find more passages in which Brinker is described with vocabulary evocative of legality and court rooms. For instance, he raising "an arresting hand," and he "qualified judiciously" a statement. He acts as though he is a prosecutor, even shouting "Liar!" at Gene, accusing him of "Trying to weasel out of it with a false confession." Later, he ridicules Leper for wanting to photograph a beaver dam. Certainly, he is sarcastic, as he leers also at Quakenbush:
"Everybody in this place is either a draft-dodging kraut or a...a..." the scornful force of his tone turned the word into a curse, "a nat-u-ral-ist!"
With the old man who supervises the boys as they work to free the freight car immobilized in the snow, the bossy Brinker acts as though he is the supervisor, asking the man if the trains should not be called "unrolling stock."
Leper, on the other hand, is more genuine, although also more vulnerable and weaker. Gene describes him as
the person who was most often and most emphatically taken by surprise, by this [the war and the first snow of winter] and every other shift in our life at Devon.
One day in the winter, also in Chapter 7, Gene remarks that Leper looks like "a burlesque explorer" as he is dressed for skiing, but not the fast downhill that others prefer. Leper says, "I just like to go along and see what I'm passing and enjoy myself." Leper has to fight to defend his way of thinking.
As one of his "vagaries," Leper is the first to join the army, "satisbying one of his urges to participate in nature." Leper is wooed by the united States ski troops' film shown at school; Leper explains that the war is the test to see "who've been evolving the right way [to]survive."
Later, Gene learns that Leper has "escaped." When Gene goes to his house, he notices Leper's appearance:
he looked at me, and I noticed the sleft side of his upper lip lift once or twice as though he was about to snarl or cry. Then I realized that this had nothing to do with his mood, that it was involuntary....I saw tears trembling in his eyes.
Although he is broken and filled with terror, Leper has the temerity to challenge Gene, who later admits that Leper is "closer to the truth."
"You always were a lord of the manor, weren't you? A swell guy, except when the chips were down. You always were a savage underneath."