One of the overriding themes of Crispin, and one that both Bear and Crispin fight against, is the powerful role that fate plays in human life. Bear is a conscious and willing rebel against fate. Crispin starts as a much more passive and accidental rebel, but he slowly converts to Bear’s self-assertive ways. The first way that fate affects human life in Crispin is through shaping English society: each person is born into a specific location, both geographic and social, and expects to stay there throughout his or her entire life. The second way is the plagues that sweep the land. In a world before advanced medicine, life or death was often just a matter of chance.

Christianity and its role in society are analyzed at great length and from a range of perspectives in Crispin. Crispin experiences the kindness of Christianity in Father Quinel, who genuinely cares for him and his mother and tries to help them. However, Father Quinel also explains the Christian underpinnings of their society in ways that make it seem like God wants things to be precisely as they are (a common period belief). Later, Bear, who had trained to be a priest, methodically challenges common beliefs about Christianity. He is cheerfully profane, but he makes a point of showing respect to the church. Bear overflows with his own brand of joy and human kindness, but he does not behave as the church would have him. He is a Christian rebel against Christian structures.

Two physical objects signify the complex nature of Christianity in Crispin. The first is the grandeur of the cathedral in Great Wexly. It is beautiful enough to awe Crispin. It also hosts more wealth than would be needed to feed Crispin’s entire village, and right next to it is the palace where Bear is tortured, showing the church’s coexistence with pain. The other object is Crispin’s cross of lead. He cherishes it, and prays with it—but he cannot read what it says. He must take others’ words as explanations of his own symbol of faith.

When Crispin’s mother dies, John Aycliffe declares him a “wolf’s head,” which shows the precarious nature of society in the Middle Ages. Putting Crispin outside his society spurs him to see more of it than most in his time. This is spurred on by Bear, who is, along with John Ball, a voice of social criticism and early democracy. Between Crispin’s need and Bear’s drive, considerable attention is paid to all aspects of society. Bear explains class structures as they travel, pointing out how people’s clothes and bearing mark their specific places in society. The tremendous gaps and tensions between classes are underscored by Lady Furnival’s disdain for peasants and by the violence that Crispin’s noble parentage generates.

For Crispin, and for others throughout the novel, what is right is shaped by a tension between duty and love. At first, Crispin is willing to stay in Stromford after his mother’s death and do what is demanded of him. However, once he is driven out into the world, he must choose for himself. When Bear traps him in the church, Crispin does not want to stay with him, but must because of the oath he swears. Even John Aycliffe, the novel’s major villain, finds oaths binding and lets them guide his actions. On the other hand, as Bear frees Crispin’s mind, the boy is free to act on the demands of his heart. These lead him to disobey Bear and follow him through Great Wexly—and to risk his life to warn Bear and the other conspirators. It is what leads Crispin to break Bear out of a dungeon at the risk of his own life rather than flee Great Wexly in relative safety.