As Gene stares at the tree from which Finny fell, Knowles uses an idiom and personification to illustrate Gene's reflections on time, change, and memory:
The tree was not only stripped by the cold season, it seemed weary from age, enfeebled, dry. I was thankful, very thankful that I had seen it. So the more things remain the same, the more they change after all—plus c’est la même chose, plus ça change.
The French idiom Gene uses here translates to "the more things remain the same, the more they change." It captures one of the novel’s central ideas: that while nothing is ever actually unchanging, people tend to repeat their mistakes and return to the same patterns of behavior. The only thing that’s unchanging is the relationship between continuity and transformation. Here, Gene notes that although the tree is still standing, its appearance has evolved over the 15 years that have passed. Like the Devon School itself, it has both fundamentally changed and remained the same.
The personification of the tree as "weary from age, enfeebled, dry" also endows it with human traits. The tree played such an important role in Gene’s past that it takes on an agency of its own here. By depicting the tree as an “enfeebled” and aged being, Gene projects his emotions about returning to the Devon School onto it.
After the carnival, in Chapter 9, Knowles uses an idiom and a simile to convey the tension and strain between Gene and Finny as their relationship flirts with disaster. Gene observes Finny’s very precarious emotional state:
He gave me a long, pondering look, his face closed and concentrating while behind it his mind plainly teetered between fury and hilarity; I think if I had batted an eye he would have hit me. The carnival’s breaking apart into a riot hung like a bomb between us.
When someone uses the idiom "batted an eye," they are usually referring to the idea of making a very small movement, gesture, or sound that might disturb a situation. In this instance, Gene is doing this, but he’s also literally referring to blinking. He feels that even the smallest movement might provoke Finny into violent action. Gene’s constant awareness of Finny’s emotional state reflects how well he knows his friend. He searches every subtle cue he can spot for signs of potential aggression.
The simile "hung like a bomb" likens the tension between the boys to the dread of an unexploded bomb falling. The unresolved emotions between Gene and Finny—paired with the chaos and noise of the carnival around them—make Gene feel that Finny is seconds away from losing his temper and “detonating” the bomb.