While Amory embraces Isabelle, his shirt-stud hurts her neck and leaves a mark. Out of this incident, a small argument erupts in which Isabelle accuses Amory of being completely egocentric. He realizes that they actually do not love each other and leaves quickly; the affair is over.
Having failed a course the semester before, Amory returns to school early to study and take a make-up exam. But even though failing the make-up exam would disbar him from the newspaper and campus success, he does not study, and fails. Amory decides that he has conformed too much in striving for social success and believes that in failing the exam, he has rediscovered "the fundamental Amory."
Amory's father passes away and Amory attends the burial without emotion. What does interest him is the finances of his family, which are diminishing because of some bad investments.
Upon his return to the East, Amory visits Monsignor Darcy in New York. Darcy makes a distinction between "personalities" and "personages." The distinction is somewhat vague but the former, he explains, are a constant entity, while the latter gather experiences like medals, losing and gaining them with no effect. Darcy convinces Amory that Amory has given himself a new chance at life, and Amory leaves feeling renewed.
Amory disappears from the social scene at school and writes a scornful poem denouncing those who still participate. Kerry Holiday leaves school to enlist in the aviation corps called the Lafayette Escadrille, a chivalrous decision that Amory admires.
On one of his trips to New York, Amory and a drunken friend are out with two girls. The group heads back to one of the girls' apartments, where Amory thinks he sees a man with curling, fourteenth-century shoes staring at him: the devil. He flees to the alley and, in a rather psychedelic nightmare, believes he is being followed by the devil, or that he is following the devil. He falls to the ground, saying he wants "someone stupid," someone good, and sees the face of Dick Humbird. Amory continues to be plagued by what he perceives to be the horror around him. He returns to his room in Princeton, where Tom, too, sees the devil watching Amory. The two discuss it all night long.
Amory's affair with Isabelle ends with the same abruptness with which it began. The fact that such a small incident could doom their affair reveals the shallowness with which Amory entered the romance and the extent to which he was playing the role of lover; he was not truly in love. Just as he adapted himself to the role of Princeton socialite, so had he assumed the role of lover. This shows his youth and innocence of his character.
The shallowness of his role as a Princeton success is revealed shortly after in his refusal to study for his make-up exam. Though initially annoyed by his failure, Amory takes it as an opportunity to rediscover "the fundamental Amory," realizing that prep school had divested him of the importance of the way his mother raised him, and that he has become conventionalized. His failure allows him to reexamine himself, and this reconnects him with his true self, the trappings of society removed.
Amory's discussion with Darcy serves to further indicate his true character. His conception of himself as a "personage" rather than a "personality" presents the fundamental Amory as one who is able to collect successes and then lose them without it affecting his self-image. This conception allows for Amory to achieve a sense of success or confidence even in the absence of socially recognized successes. He becomes more of a whole person and less of a reputation.
Perhaps as a result of this discussion, Amory removes himself from the social scene at Princeton. He no longer needs "success" there to maintain a healthy self-image; he has stripped itself of this superfluity.
Yet Amory is still haunted. His vision of the devil is a difficult one to dissect and stands as a reminder of his young age. In many ways, it highlights the moral backbone that sets Amory apart from his peers. The phantasm appears in the midst of a morally vacuous party and Amory, in seeing the devil, sees to the core of the situation. Amory has a conscience. The way in which Amory bolts from the company of his friends, totally disregarding them, shows that he no longer cares about social image. The scene is a poignant culmination of Amory's removing himself from convention, "the egotist considering," as the title of the chapter says. The fact that Tom sees this devil watching Amory as well hints at the connection between these two and suggests Tom's own independence from the conventionalizing forces of society.
Amory's utter lack of interest in the death of his father, beyond its finances, highlights his egotism. This scene serves both to show to what extent Amory is independent from his family, and to introduce the issue of his finances. Though quite wealthy when Amory was a child, the family resources are diminishing and will have utterly evaporated by the end of the novel.