These three studies concentrate on the changes in religious thought and institutions in the eleventh and twelfth centuries, and include not only monks and nuns but also less organized types of life such as hermits, recluses, crusaders, and penitents. "The Interpretation of Mary and Martha" deals primarily with the balance of action and contemplation in Christian life; "The Ideal of the Imitation of Christ" studies the growing emphasis on the human Christ, especially His body and wounds; and "The Orders of Society" looks at the conceptual divisions of society and the emergence of the modern idea of a middle class.