Book excerpt: This substantial work by one of Europe's most respected twentieth-century legal minds unpacks Luther's doctrine of law, showing how it derived from his central theological concern, justification by faith. "When Johannes Heckel's Lex Charitatis appeared more than half a century ago, it brought new clarity to the much-disputed issue of Luther's understanding of the law and of God's governance of his created order. The Wittenberg reformer's use of the language of 'two kingdoms' and 'two governances' is still fiercely debated; having Heckel's work in English will assist scholars and students alike in putting Luther's insights to use in the context of twenty-first-century problems." -- Robert Kolb, Concordia Seminary