On chapter 21 Which book does Jarvis turn to, to help explain his son's reasoning?

Jarvis continues to read his son's manuscript, and reads the last unfinished paragraph: "The truth is that our Christian civilization is riddled through and through with dilemma. We believe in the brotherhood of man, but we do not want it in South Africa . . . We believe in help for the underdog, but we want him to stay under. . . The truth is that our civilization is not Christian; it is a tragic compound of great ideal and fearful practice, of high assurance and desperate anxiety, of loving charity and fearful clutching of possessions." It ends with the words "allow me a minute." Jarvis sits, deeply moved by the words.