Explores in great detail the "problem of Church and State" in thirteenth-century France. It argues that while the spiritual and temporal powers existed, they were not parallel structures attempting to govern the same social space in a contest over sovereignty. Rather, the spiritual and the temporal powers were wrapped up together in a differentiated and sacramental world, and both included the other as aspects of their very identity. The realm was governed not by proto-absolutist institutions, but rather by networks of friends that cut across lay/clerical lines. Ultimately, the king's "fullness of power" and the papacy's "fullness of power" came together to govern a single social order.

Before Church and State reconstructs this social order through a detailed examination of the documentary evidence, arguing that the order was fundamentally sacramental and that it was ultimately congruent with contemporary incarnational and trinitarian theologies and the notions of proper order that they supported. Because of this, modern categories of secular politics cannot be made to capture its essence but rather paint always a distorted portrait in modernity's image.

In addition to a detailed reconstruction of the institutions of the kingdom, the work offers a reading of the political and ecclesiological thought of St. Thomas Aquinas that is consistent with that reconstruction. Thomas is here rescued from the liberal or Whig reading that has dominated in recent centuries and is returned to his thirteenth century context.

Previously, scholars interested in challenging modern conceptions of the secular and the religious when treating the Middle Ages, have had to rely largely on historical scholarship written from within the conventional modern paradigm. In this text, Jones provides these scholars with a methodologically and technically rigorous alternative. If the book's thesis is widely accepted, it will call for the reconsideration of the accepted narrative of medieval Church and State.