Chris is a bit of an idealist in this play. He is insulated from financial hardship because his father owns a profitable business. He believes that his father is innocent. Chris is unwilling to acknowledge that his father could be guilty because he does not imagine that he, himself, could be so moral himself, if his father is not.
When he discovers that his father is guilty, he is emotionally crushed, but his sense of honor requires him to assert that Joe Keller should go back to prison for his crime. Although he has a very difficult time admitting it out loud that Joe should return to prison, and he won't be the one to make sure he goes to prison, instead, Chris just wants to run away.
"Chris rejoins the group and proposes yet another plan of action. He will depart immediately and leave his current life behind him, even Ann, whom he claims would surely grow to hate him over time for his association with the man and business that destroyed her family. He will neither open the case again nor jail his father."
"It seems that Chris has become, in his own words, too “practical” to enforce his own ideals. His claims are put to an immediate test as Joe reenters and engages his son in a final confrontation."