Book excerpt: In Beyond Reformation? An Essay on William Langland’s Piers Plowman and the End of Constantinian Christianity, David Aers presents a sustained and profound close reading of the final version of William Langland’s Piers Plowman, the most searching Christian poem of the Middle Ages in English. His reading, most unusually, seeks to explore the relations of Langland's poem to both medieval and early modern reformations together with the ending of Constantinian Christianity. Aers concentrates on Langland’s extraordinarily rich ecclesiastic politics and on his account of Christian virtues and the struggles of Conscience to discern how to go on in his often baffling culture. The poem’s complex allegory engages with most institutions and forms of life. In doing so, it explores moral languages and their relations to current practices and social tendencies. Langland’s vision conveys a strange sense that in his historical moment some moral concepts were being transformed and some traditions the author cherished were becoming unintelligible. Beyond Reformation? seeks to show how Langland grasped subtle shifts that were difficult to discern in the fourteenth century but were to become forces with a powerful future in shaping Western Christianity. The essay form that Aers has chosen for his book contributes to the effectiveness of the argument he develops in tandem with the structure of Langland’s poem: he sustains and tests his argument in a series of steps or “passus,” a Langlandian mode of proceeding. His essay unfolds an argument about medieval and early modern forms of Constantinian Christianity and reformation, and the way in which Langland's own vision of a secularizing, de-Christianizing late medieval church draws him toward the idea of a church of “fools,” beyond papacy, priesthood, hierarchy, and institutions. For Aers, Langland opens up serious diachronic issues concerning Christianity and culture. His essay includes a brief summary of the poem and modern translations alongside the original medieval English. It will challenge specialists on Langland's poem and supply valuable resources of thought for anyone who continues to struggle with the church of today.