Why do the characters in The Sun Also Rises deplore Robert Cohn?Is it because of his religion, his low self esteem etc.?
Robert Cohn is smug and self-satisfied, while also needing to prove himself. These traits stand nearly in direct opposition to those of Jake, the novel's anchor of moral perspective and judgement. Cohn's personality that is the central reason that others dislike him.
The fact that Cohn is Jewish is certainly discussed, but this fact is cosmetic in comparison to the deeper problems with his character and it is used to deride Cohn because it is simpler than commenting on the more complex issues of personality.
When Cohn appears in the novel, he is flushed with excitement over a novel he has published.
The success of his first novel goes straight to his head as he lives out his dreams of chivalry and romance; Frances becomes his mistress.
Taking on a mistress and moving to Europe, Cohn is assuming the life of Jake and his cohort, though for Cohn this seems like a mere romp. Cohn does not respect the life of the expatriates in Jake's circle, or at least does not understand the passions, values, and beliefs that are integral to the decision to live as they do.
Because Cohn cannot create his own version of the group’s code, he becomes the subject of persecution.
Cohn is a poseur, whose presence is demeaning to Jake and Brett because, for them, their lifestyle has been chosen for reasons that are real and even unavoidable. They have lost something significant and have little hope of replacing what they have lost. Cohn, a wealthy and lucky man, is merely playing in Europe.
Where there is clear desperation for the others, there is none for Cohn.
...as Brett says, he is not “one of us.”