The main themes of the final third of Babbitt are rebellion and the return to conformity. George Babbitt experiments with vacations, jumping into liberal politics, befriending socialist litigator Seneca Doane, having an extra-marital affair with Tanis Judique and cavorting with flappers.
With each effort of rebellion, Babbitt becomes disillusioned, finding, for example, that the flapper subculture has just as many rules of conformity as his own previous life. When Babbitt’s friends learn of his rebellion, they ostracize him and boycott his real-estate business, offering him a chance at redemption through joining the “Good Citizens League,” an offer Babbitt quickly rejects, feeling bullied.
Babbitt realizes that his attempts at rebellion are futile, but continues with them until his wife becomes ill and needs an operation to remove her appendix. Babbitt has an epiphany, realizing the value of his married life, even though it is not exciting or romanticized and vows to give up his rebellion to care for his wife.
His friends welcome him back into the Booster club and Babbitt returns to conformity, although he does lose all of his empathy and hope for meaningful life. When Babbitt learns that his son has married before finishing college, he does not denounce the marriage, as the rest of the family do. He encourages the young man to make his own life and not merely do what is expected of him and conform to the expectations of society.