Luther vs Erasmus: The First Written Debate of the Reformation

The first written debate of the Reformation occurred in 1525 between Martin Luther and the great Roman Catholic humanist scholar Desiderius Erasmus.

The topic of their debate was so important to Luther that he correctly recognised they were debating the “grand hinge” of the Reformation, an issue so central that everything else was mere trivia (what Luther called the “baubles” of “popery and purgatory”). So what was the grand hinge of the Reformation according to Luther?

It was the question as to whether man is truly and properly free. Does he have a free will? Or is his will in bondage to one power or another?

Of course this question does not sit in a vacuum. Questions about human freedom are also questions about the being and power of God, sin, and even reality itself. In fact, whatever position you hold will have real implications for how you see the gospel and how you behave and function.

Erasmus was a humanist – in the original scholarly sense – and what emerges from his discourse is a very modern indolence that proves that the fashionably laidback smug scholarly attitude is not new.

Desiderius Erasmus.

Erasmus claims he does not have a view, and claims he cannot decide which “traditional” posture he makes his own. Instead Erasmus prefers to state a minimalist view in comfortably agnostic and cloudy language. He says:

For these reasons then, I must confess that I have not yet formed a definite opinion on any of the numerous traditional views regarding the freedom of the will; all I am willing to assert is that the will enjoys some power of freedom.

On the surface this sounds like an intellectually-honest position, even humble. But it is a very devious position. You would hardly guess that this prefaces a detailed scholarly effort to overturn Luther’s position.

Thus, Erasmus says on the one hand that he simply does not know enough to come to a firm view about the freedom of the will, but at the same time he apparently knows enough to firmly reject Luther’s position!

I call this a “very modern indolence” because the same intellectual dishonesty is witnessed in dialogues on the subject today. People often claim they really do not know (“speaking for myself”), or they will profess not to have a strong opinion. Yet, they all exhibit remarkable a clarity in knowing that the human will is not in bondage as Luther argues. If the human will is not in bondage, this is the same thing as declaring that it possesses freedom and that is the same thing as a claim of at least some knowledge.

It is oddly comforting to observe such dishonest slips of mind and weasel phrases in a text that is 500 years old. It reminds us that there is nothing new under the sun. Humankind has always been prone to intellectual gimmicks to suppress truth. Dishonesty is not a 21st century disease. We have not blundered suddenly into an era of unexpected intellectual sterility. It has always been thus.

In writing, Erasmus appears almost aristocratic. He uses refined and languid prose. For him, the matter of free will appears to be one of mere philosophical interest. It stimulates like a good cup of coffee. It might even be a good opportunity in which to put the “elephant” of Luther in his place to the cheers and applause of Roman Catholic Europe.


Luther by contrast is fiery and coarse. He writes as he speaks. He writes with broken run-on sentences, dangling phrases, unreferenced pronouns and stacks of parentheses all over the place. Luther takes everything seriously. His humour rises only as high as sarcasm if it serves to demolish his opponent. Maybe he ascends to dry wit, but never without the tang of ridicule. Moreover, he rebuts everything at great length. His quill scratches the paper as fast as it can go, followed by the eyes of its director who cannot divest himself fast enough of all the words he wishes to say.

Yet Luther’s prose also carries the distinct aroma of intellectual honesty, sincerity and depth while Erasmus dynamites all of these qualities early in his piece. Firstly, Erasmus clearly does take a definite opinion, despite claiming the opposite. And secondly, to offer a thesis that the human will “enjoys some power of freedom” is so hazy and ill-defined as to be a truly pointless and meaningless position. Erasmus has a strong habit of foggy terminology.

Erasmus also offers a range of arguments against Luther’s position, of which we will consider only two because each deserves a detailed analysis. These arguments remain important for Protestants today, insofar as both Roman Catholics and Arminians often rely on substantially similar points.

Martin Luther Translating the Bible, Wartburg Castle, 1521 by Eugene Siberdt.

Argument 1: Scripture is Unclear

Erasmus first begins with an assault on the perspecuity of scripture:

Holy scripture contains secrets into which God does not want us to penetrate too deeply, because if we attempt to do so, increasing darkness envelopes us, so that we might come to recognise in this manner both the unfathomable majesty of divine wisdom and the feebleness of the human mind.

Pomponius Mela [a Spanish explorer], for instance, speaks of a certain Corycian grotto which at first entices intruders by its charm, and later frightens them and fills them with terror because of the majesty of the indwelling divinity… I think it more prudent and pious to exclaim with Paul, “Oh, the depth of the riches of the wisdom of the knowledge of God! How incomprehensible are his judgements and how unsearchable his ways!”

Erasmus’ argument here is disingenuous to say the least. Surely one of the most preposterous arguments anyone could make is that things have been revealed by God with the express intention that they should obscure truths and keep them hidden. Why reveal anything at all under such an economy?

Erasmus’ argument here fails on three counts.

Firstly, he simply begs the question that such a principle even exists. But scripture itself never enjoins its readers not to go “too deep” into any topic upon which it speaks. Quite the opposite. It commends meditations on the Lord’s laws and decrees “both day and night” and blesses such who do so (Psalm 1:2).

Secondly, Erasmus leaves us clueless about which secrets exactly scripture designs to keep from us. How do we know what constitutes a scriptural secret? What in scripture are we not intended to explore? Since he offers no way to answer these questions, it becomes a shamelessly arbitrary argument.

Thirdly, Erasmus offers no clarity as to what “too deep” might be. Is too deep when you do a survey of the entire Bible on a particular issue? Is too deep when you thoroughly analyse a particular passage? Erasmus never tells us. All we know for sure is that “too deep” involves any study that would lead you to Luther’s conclusion.

Finally, note that Erasmus simply assumes his conclusion from the outset. He assumes the scriptures are opaque on the matter of human free will, and therefore there is no point in looking more deeply. Talk about a circular argument.

Luther’s response pushes back on Erasmus’ assumptions:

Your allusion to the Corycian cave is therefore not to purpose. The case is not as you represent it, with respect to the Scriptures. The most abstruse mysteries and those of greatest majesty, are no longer in retreat, but stand at the very door of the cave, in open space, drawn out and exposed to view.

For Christ has opened our understanding that we should understand the Scriptures (Luk 24.45). And the Gospel has been preached to every creature (Mar 16.15; Col 1.23). Their sound has gone out into all the land (Psa 19.4). And all things which have been written,
have been written for our learning (Rom 15.4). Also, all Scripture having been written by inspiration of God, is useful for teaching (2 Tim 3.16).

You and all your Sophists come and produce a single mystery in
the Scriptures which still remains shut up. The fact that so many truths are still shut up to many, does not arise from any obscurity in the Scriptures but from their own blindness or carelessness, which is such that they take no pains to discern the truth, though it is most evident.

Luther fires back with scripture’s own testimony to its value, usefulness, clarity, and perspicuity.

“It is not that the scriptures are unclear,” argues Luther, “it is that people approach it with a darkened mind or in a slipshod way so they miss its truth.”

Luther goes on to explain that there is a twofold perspicuity to scripture. There is both an internal and external clearness to scripture. Externally, scripture is clear on all of the subjects upon which it teaches because it possesses the clarity and intelligibility of the One who spoke it forth. To malign scripture is to malign its originator. To say scripture is unclear is to presume God cannot communicate well.

Therefore Luther states: “nothing at all has been left obscure or ambiguous; rather, everything that is contained in the Scriptures has been drawn out into the most assured light, and declared to the whole world by the ministry of the word”.

But, in regards to internal clearness, Luther says:

…no one discerns an iota of Scripture, except one who has the Spirit of God. All men have a darkened heart; so that, even though they repeat and are able to quote every passage of Scripture, they neither understand nor truly know anything that is contained in these passages. Nor do they believe that there is a God, or that they are themselves God’s creatures, or anything else.

As a good humanist Erasmus would hardly grant this possibility. In his own time, and certainly long before, Roman Catholicism had long downplayed the noetic effects of the Fall because it has allied so much of its formal dogma to Aristotle, especially since Thomas Aquinas.

This admiration for pagan philosophers tended to result in a zeal and enthusiasm for human reason among its theologians. Aquinas completed this fusion with his “two storey model” of finely-tuned theology in harmony with Aristotelian thought. For this, Aquinas received the distinction of “Doctor of the Church” and his output has been required study for priests and Roman theologians ever since. Thus, Roman Catholicism has generally maintained the view that sin has damaged man’s will more than it has damaged man’s mind. The logical conclusion that must arise from such a view is that fallen man is able to reason rightly (with a little help) even about God to some degree, or otherwise, what becomes of Aristotle?

To grant Luther’s point here is to hand Luther victory. If the human mind is so impacted by sin that it is prone to wrongful conclusions even about God’s word, then man necessarily requires God’s help and grace to even arrive at the truth when it is staring at him in the face. If this is the case for divine revelation, how can man possibly be truly free in any other sphere of life?

Argument 2: Not Necessary for Piety

Next Erasmus simply moves the goal posts and makes the sweeping claims that a view of free will is necessary for Christian piety.

In my opinion the implications of the the freedom of the will in Holy Scripture are as follows: if we are on the road to piety, we should continue to improve eagerly and forget what lies behind us; if we have become involved with sin, we should make every effort to extricate ourselves, to accept the remedy of penance, and to solicit the mercy of the Lord, without which neither the human will nor its striving is effective… in my opinion it used to be sufficient for Christian piety to cling to these truths.

This is a crafty effort to raise a strawman.

“You see, Luther,” says Erasmus, his forehead furrowed, “before we get into the nitty-gritty, we must first weigh the implications of doctrinal teaching. Clearly free will teaching is the most fruitful when it comes to the really important matter of being a good Christian. In the old days people got along quite well and lived pious lives secure in their free will belief and all was well. Why come along and rock the boat?”

But of course, the question in dispute is not whether free will has utility to bring about a pious life. Indeed, the implications or ramifications of a doctrine should not be a first order question, because anyone may develop all kinds of speculative objections. “Feminist theologians” do this all the time when it comes to the doctrine of the Trinity; in particular, the use of male pronouns for the Persons of the Trinity.

“This doctrine promotes a patriarchal view of the world!” they complain with a straight face, “And it promotes the idea that men are closer to God than women. It has a damaging effect on women and disempowers them in the church!”

Such objections – even if they were not ridiculous – are secondary matters to the primary criterion of truth. The most important question is whether something is true. Has it been revealed by God? Is it taught in scripture? The supreme question is not whether a doctrine is any good for a particular purpose. Neither whether a doctrine is better or worse for a particular outcome. The greatest and most central question above all others is whether something is true.

Thus, even if Erasmus were right and free will teaching makes a real impact on the level of piety in a person’s life – externally observed piety, at least – there is no reason to suppose that free will teaching is actually true.

Erasmus must surely have been aware of sects of heretics that dot church history who practiced an absurdly high standard of piety as he defines it. The Donatists, for example, argued that the clergy in the church needed to be morally perfect in order to validly consecrate sacraments and discharge their ministries. Would such a teaching not be a great impetus to piety? Most surely it was and would be. Any hint of moral imperfection in Donatist churches resulted in a ruthless purge. But despite their high moral code, their doctrine was still rejected as false.

The Donatist Controversy

Erasmus’ determination to maintain a free will philosophy necessarily means he cannot be a consistent Christian reasoner from a foundation of the scriptures, regardless of what he might say later. Free will arguments almost always arise from philosophy and depend principally upon philosophy. Unfortunately, is almost impossible to get a free will sophist to critique their philosophy or subject it to the scriptures because for them it is so unassailable it needs no proof or support. But in the process, they never seem to grasp that their arguments are void of content that is uniquely Christian. In fact, people who argue for free will often make the same arguments as Hindus or Muslims, and even shave the Christian content off theology altogether in order to carry the point.

This is something that Luther recognises in Erasmus’ presentation. He says:

Assuredly, any Jew or Heathen who had no knowledge at all of Christ, would find it easy enough to draw out such a pattern of faith as yours. You do not mention Christ in a single jot of it, as though you thought that Christian piety might subsist without Christ — if only God, whose nature is most merciful, is worshipped with all our might. What shall I say here, Erasmus? That your whole air is
Lucian, and your breath a vast surfeit of Epicurus?

If you account this question an unnecessary one for Christians, then take yourself off the stage, I pray; for we account it necessary…

In essence, Luther criticises Erasmus’ minimalist form of piety and accuses him of being in bed with naturalistic philosophy and pagan moral philosophers, rather than in warm fellowship with Christian theology. If “piety” is drained of all Christian content and reduced to merely “being better than I was” in some loose external fashion, then what is the point of Christ at all?

Luther angrily bats away Erasmus’ practically proto-deistic conception of piety and replaces the issue front and centre. It is necessary, he says. So deal with it.

He goes on to attack Erasmus and ask that if it is merely a curiosity to know whether God foreordained men to eternal life, and the exact role of the human will – active or passive – in its relation to grace, then what exactly constitutes religious substance?

If it is irreligious, if it is curious, if it is superfluous, as you say it is, to
know whether God foreknows anything contingently, or whether our will is active in those things which pertain to everlasting salvation or merely passive, grace meanwhile being the agent… what will then be religious, I ask? What is important? What is useful
to be known? This is perfect trifling, Erasmus! This is too much.

So we see that bad arguments are not new, and bad reasoning about the issue of the bondage of the human will is very old.