Why do you think The End of the Affair is Modernist ?
In defining the qualities of Modernism, Virginia Woolf writes of a shift that takes place within human consciousness. This sense of change is an essential part of the Modernist movement: "All human relations shifted... and when human relations change there is at the same time a change in religion, conduct, politics, and literature.” With this understanding, The End of the Affair can be seen as Modernist. One way is in how Bendrix's understanding of consciousness is "shifted." Bendrix has to experience the shift from a specific romantic type of love to a wider construction that encompasses the divine. Bendrix's sense of shift and change is a part of the shift that takes place within his characterization. This is one way in which Bendrix embraces a sense of Modernism in his change.
I think that another way in which Modernism is evident can be seen in the relationship itself. The ending of the affair is an abrupt one, something that Bendrix fails to see as possessing any rational understanding. Even though he comes to the realization that Sarah ended it as a sacrifice for something larger, Bendrix fails to understand the rational calculus for the affair ending. In addition to this, Bendrix's own irrationally jealousy toward Sarah undermined any real and sustaining love between both. This represents Modernist tendencies in its assertion that rationality is absent, reflective of another "shift" in consciousness and being in the world.
Graham Greene's novel has elements of modernism. It is a circular narrative that ends roughly where it begins and goes back in time, and that kind of structure is modernist. The novel begins with the lines, "A story has no beginning and no end; arbitrarily one chooses a moment of experience from which to look back or look ahead." This type of circular narrative that has no beginning or end point and the way in which subjective opinion and experience are presented instead of objective truth is modernist in nature.
The beginning of the novel also points to the narrator's uncertainty and unreliability. He states that he has chosen one moment in time in which to begin a tale that exposes his greater uncertainty about life. Bendrix, the narrator, begins the tale by hating Henry Miles and his wife, Sarah. Throughout the course of the novel, he realizes that he has understood very little about Sarah, a woman with whom he earlier had an affair, and has understood very little about the nature of God. The uncertainty that the narrator faces and his self-doubt also mark this as a modern novel. While an earlier form of the novel presented a definitive view of reality, this novel suggests reality is subjective, which is a feature of modernism.