This pioneering book brings the 16th-century reformer, Martin Luther, and the 15th-century philosopher-cardinal, Nicholas of Cusa, into conversation on issues long considered divisive. It compares their thought on central issues such as justification, the cross, learned ignorance, hiddenness, Islam, non-contradiction, reform, freedom of the will, and implications for ecumenical dialogue. Without appealing to a “common denominator” or “little Luthers” before Luther, the methodology of “differentiated consensus” allows new perspectives on two of the best-known theologians and reformers of their time.