Perhaps it is through the weaknesses of his friends that Jake's own strength grows most in Ernest Hemingway's breakthrough novel, The Sun Also Rises. Jake's week spent at the bullfights at the festival of San Fermin has given him a stronger insight into his friends and their own human frailties. Cohn is a follower who turns on his friends when a woman comes between them. His punch is strong, but his heart is weak, and he will probably return to Frances. Mike's boozing is out of control and he is a leech to everyone who knows him. The aging Lady Ashley has little control over her heartstrings, and she will soon move on to yet another man. She is Jake's one true friend, however, and their friendship will endure in part because he is incapable of responding to her sexual advances. Additionally, Jake has literally had some sense knocked into him by Cohn's punches, for when he returns to his hotel,

... everything looked new and changed... It was all different.

Jake's writing talents are intact; aside from his impotency, he is physically strong; and, unlike the others, he is financially secure. He will survive with or without those around him.