'The Law Written on the Heart': Natural Law and Equity in Early Lutheran Thought

This Article analyzes the transformation of Western legal philosophy in the sixteenth-century Lutheran Reformation, with a focus on the legal thought of theologian Martin Luther, moral philosopher Philip Melanchthon, and legal theorist Johann Oldendorp. Starting with Luther's two kingdoms theory, Melanchton developed an intricate theory of natural law based not only on the law written on the hearts of all persons, but also on the law rewritten in the Decalogue, whose two tables provided the founding principles of religious law and civil law respectively. Building on both Luther and Melanchthon, Oldendorp developed an original theory of equity and equitable law making and law enforcement as part of a broader biblical-based theory of natural law. Together these writers, laid the foundations for a new legal, political, and social theory which dominated Lutheran Germany and Scandinavia for the next three centuries.