⭐⭐ The most direct clash on this thread in a thousand years — and the only time on the whole thread that the two leading figures fought each other directly. In the first part, Augustine and Pelagius never met in their lives.
The issue
Does the human will have any part in salvation?
Claim
Luther, On the Bondage of the Will (1525): only God has free will; human beings do not. The human will is like a beast of burden; God rides it or Satan rides it, and “Nor is it in the power of its own will to choose, to which rider it will run, nor which it will seek.” He firmly rejected every form of synergism, holding that only evangelical monergism, as Olson puts it, can preserve the New Testament teaching that salvation is a pure gift, and the majesty of God. ⚠ He charged Erasmus, Olson reports, with being, if not an outright Pelagian heretic, then at least fallen into the rut of Semi-Pelagianism.
Counterclaim
Erasmus, On Free Will (1524), as Olson gives his words: although free choice has been damaged by sin, it has not been destroyed by it … it has not been wholly rooted out, except in those whose grievous sins have become a second nature. He granted that a helping grace is absolutely indispensable to the free will of fallen humanity, but insisted that, with the help of grace, the damaged free will can choose to play a part in salvation — a synergism in which, as Olson puts it, grace is the chief partner. ⚠ He charged in turn that Luther's teaching was absurd and fanatical, contrary to Scripture and to the witness of the fathers before Augustine, and even accused Luther of believing Manichaeism.
The ruling
⭐ No ruling — no council, no anathema; the two books were simply left standing side by side.
What was at stake for salvation
Both sides were fighting for salvation, in opposite directions: Luther was guarding salvation as a pure gift and the majesty of God; Erasmus was guarding the reality of the human response in salvation. ⭐ We think the most valuable thing about this debate is precisely that it had no ruling — two views stand side by side, and readers read for themselves.
Aftermath
⭐ Luther's reaction to this debate deserves its own note. Erasmus chose this subject to fight over, and, Olson writes, Luther was delighted and congratulated the Dutch scholar on his sharp eye for going straight to the heart of their difference — the old question of monergism versus synergism. Even Luther himself thought this was the heart of the division — not indulgences, not the power of the pope. ⚠ Two more things to remember: first, the labels the two sides pinned on each other were exactly the same two as in the controversy over Pelagius a thousand years earlier (Pelagianism / Manichaeism). Second, both men came from the Augustinian tradition, but from different orders: Luther was an Augustinian friar (of the Observant congregation at Erfurt), Erasmus an Augustinian canon regular (at Steyn).