The debate between Martin Luther and Erasmus on the nature of the human will is one of the most significant in the history of the Christian church. In the course of the dispute Erasmus declared a deep distaste for Luther’s manner of expressing himself in positive and categorical terms. “So great is my dislike of assertions,” wrote Erasmus, ‘that I prefer the views of the Sceptics wherever the inviolable authority of Scripture and the decision of the Church permit.” Luther was scandalized by this failure to appreciate the propositional nature of Christian faith, and responded to Erasmus in typical fashion:

“To take no pleasure in assertions is not the mark of a Christian heart; indeed, one must delight in assertions to be a Christian at all . . . Away, now, with Sceptics . . . let us have men who will assert . . . Take away assertions, and you take away Christianity . . . What Christian can endure the idea that we should deprecate assertions? That would be denying all religion and piety in one breath” (The Bondage of the Will, 66f.).

J. I. Packer concurs with Luther and insists that “Christianity is . . . by its very nature an assertive, dogmatic faith. Luther knows, of course, that the world and the church are often bedevilled by a dogmatism which springs from nothing higher than pig-headedness, obscurantism, and sheer superstition, but he disclaims all intention of defending dogmatism of that sort. His point is not that it is never desirable to have an open mind, but simply that on the central issues of the Gospel – the person, place, and work of Jesus Christ, the sola gratia, and the way of salvation – an open mind, so far from being a true expression of Christian humility and self-distrust, is sub-Christian and indeed anti-Christian, for it argues ignorance, both theological and experimental, of the work of the Holy Spirit. The question Luther would press on anyone who, like Erasmus, extolled an undogmatic temper in Christian theology would be this: ‘Do you believe in the Holy Ghost?’” (“Luther Against Erasmus,” in Honouring the People of God, 110).