The classical discussion of the doctrine of Predestination and the problem of Free-will is still to be found in Luther's book, the Bondage of the Will. In the course of four hundred pages he ranges through profound Biblical exegesis, trenchant theological statement, narrow scholastic argument, virulent vituperation—developing, through it all, the most powerful exposition of the doctrine ever made. The question naturally arises: How far can we, in our generation, go with him? The following paragraphs suggest the main points involved, and discuss the modifications of his position that would seem to be necessary.

The initial point where Luther joins issue with Erasmus is on the unlawfulness of human speculation before the final mysteries of the Faith, and the need to put the hand upon the mouth at that point, and simply confess. Erasmus has argued that certain Christian doctrines are ambiguous, and should therefore be rejected in the interests of a more rational theology. Luther quotes Erasmus as follows and replies:

In like manner, your examples which you subjoin, not without suspicion and bitterness, are nothing at all to the purpose. Such are those concerning the distinction of Persons, the union of the divine and human natures, the unpardonable sin, the ambiguity attached to which, you say has never been cleared up. If you mean the questions of Sophists that have been agitated upon these subjects, well. But what has the all-innocent Scripture done to you, that you impute the abuse of the most wicked of men to its purity?