The development of Martin Luther's thought was both a symptom and moving force in the transformation of the Middle Ages into the modern world. Geographical discovery, an emerging scientific tradition, and a climate of social change had splintered the unity of medieval Christian culture, and these changes provided the background for Luther's theological challenge.

Preface to the Complete Edition of Luther's Latin Writings, 1545 -- The Freedom of a Christian, 1520 -- Two Kinds of Righteousness, 1519 -- A Commentary of St. Paul's Epistle to the Galatians, 1531 (Selections) -- The Bondage of the Will, 1525 (Selections) -- Sermons on the Catechism, 1528 (Selected) -- Sermon in Castle Pleissenburg, Leipzig, 1539 -- The Pagan Servitude of the Church, 1520 -- Secular Authority: To What Extent it Should be Obeyed, 1523 -- An Appeal to the Ruling Class of German Nationality as to the Amelioration of the State of Christendom, 1530.