The clarity of scripture is the establishment of all confession. Without a clear understanding of what God says in His Holy Word, every doctrine capitulates on the opinions of man. An understanding of the clarity of scripture is absolutely necessary for such doctrines for a proper confession of the Trinity, Christ Jesus, sin, death, the church, and the sacraments. The same is true concerning the clarity of Holy Scripture in the debate between Erasmus and Luther concerning the will of man. The debate between Luther and Erasmus in 1525 is best remembered for their polemics concerning either the freedom or the bondage of the will. However, the vast differences between the two concerning the clarity of Scripture is tantamount for their inevitable disagreement concerning the will of man. Luther confessed the Holy Scriptures as being clear in and of themselves without any need for outside interpretation. On the other hand, Erasmus made the assertion that Holy Scripture was cloudy in certain places so that outside interpretation was necessary for a proper understanding. Their disagreement is evident in different schools of exegesis, diverse opinions on the authority of Scripture, and an inevitable disagreement on the purpose and work of the Holy Scriptures and their outcome.
Erasmus, in De libero arbitrio, begins his argument concerning the darkness of scripture by saying,
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 recognize in this manner both the unfathomable majesty of divine wisdom and the feebleness of the human mind. [endnote 1]
Over and against this, Luther in De Servo Arbitrio, confesses,
The profoundest mysteries of the supreme Majesty are no more hidden away, but are now brought out of doors and displayed to public view. Christ has opened our understanding, that we might understand the Scriptures, and the Gospel is preached to every creature. [endnote 2]
From the outset Luther and Erasmus have contrary views concerning the clarity of Scripture. Erasmus fears the darkness of certain passages and therefore trembles before the majesty of God. In opposition to this, Luther makes the assertion that Holy Scripture is clear in every passage through the incarnation of God in Jesus Christ and therefore must be proclaimed to all of creation.
Luther and Erasmus’s opposing interpretations are revealed in their exegetical work especially in Romans 9:14 concerning the hardening of Pharaoh’s heart. Erasmus places this passage in his argument on texts that oppose the doctrine of free will. Erasmus proclaims his true colors concerning the inspiration of the Holy Spirit but also the job of the interpreter saying,
The Holy Spirit cannot contradict himself. The canonical books of Holy Scripture originated under his inspiration. Their inviolable sublimity is acknowledged and affirmed by both parties in the dispute. Therefore, one must find an interpretation, which resolves this seeming contradiction. [endnote 3]
Here Erasmus shows that both he and Luther agree that the Holy Spirit inspired the Word of God, and, therefore the sacred writings cannot contradict themselves because they have one author. However, Erasmus turns to the interpretation of church tradition or human reason when the text contradicts what his doctrine proclaims. This is evident in his interpretation of Romans 9:14ff.
Erasmus first quotes Romans 9:14 and Exodus 9, 12, and 16. He follows this with his interpretation of the text saying,
Since it is obviously contradictory that God, who is not only just, but also merciful, should have hardened the heart of a man, in order to show his might by the former’s evilness. [endnote 4]
Erasmus does not let the Scripture interpret itself, or even let the Holy Spirit interpret, but he automatically runs to the champion of allegory, Origen. Because Erasmus believes the hardening of Pharaoh’s heart seems contrary to a just and loving God, he attempts to interpret this text by following the interpretive tools of Origen as found in the early church exegetes Commentary on St. John. Erasmus’ interpretation would place the fault and guilt of a hard heart on Pharaoh instead of letting God be God and letting God harden who he will harden and have mercy upon whomever he will have mercy. Erasmus relies on the church fathers and a figure of speech to explain away what God wills.
Luther contradicts Erasmus’ understanding of the text by thundering many attacks against Erasmus. Luther begins his polemic against Erasmus saying,
But who gives us assurance that the explanation of Origen and Jerome is right? Furthermore, we agreed not to base arguments on the authority of any teacher whatsoever, but only on that of Scripture. What a crew of Origens and Jeromes does the Diatribe set against me!-but it has forgotten our agreement. [endnote 5]
Luther takes a literal interpretation of the text letting Scripture interpret itself. He has Christ at the center and therefore Christ has clarified all of Scripture. Luther has no need for allegory because all has been revealed in the incarnation, life, death, and resurrection of Jesus Christ. Luther can say, “God hardened the heart of Pharaoh,” and not have to place the blame on Pharaoh. He reads the text and proclaims what the words say. Therefore, we may conclude that Luther is literal and Erasmus is allegorical concerning their exegetical interpretation of Holy Scripture.
As is demonstrated in their contesting exegesis, both Luther and Erasmus have differing views concerning the authority of Scripture. Luther holds to a principle of Sola Scriptura allowing the Scriptures to interpret themselves. On the other hand, Erasmus uses the church, especially the early church fathers, and tradition, to interpret the Scriptures, reasoning that Scripture is not clear in and of itself.
Luther scolds Erasmus because he breaks the agreement, as mentioned above, that both he and Erasmus will use Scripture alone to make their arguments concerning the will of man. Luther himself uses the Scripture as his only authority for doctrine and Christian life, saying, “my doctrines are fortified with mighty Scripture proofs.” [endnote 6] Luther blames heresy not on the darkness of Scripture, but on the ignorance of fallen man. Luther argues that,
To many peoples a great deal remains obscure; but that is due, not to any lack of clarity in Scripture, but to their own blindness and dullness, in that they make no effort to see truth which, in itself, could not be plainer. [endnote 7]
Luther steadfastly maintains that the Scriptures are clear and therefore there is no need for the church to interpret the texts for him. He is convinced that in the fallen reason of man heresy arises. When human reason trumps the Holy Spirit, human reason triumphs and tramples underfoot a Gospel centered interpretation of Holy Scripture.
The Scriptures inherently themselves cannot produce heresy. However, a lack of understanding and man’s insatiable desire to interpret God gives rise to false doctrine. Therefore, clarity becomes an issue. Luther maintains it is the interpreter who is unclear-not the Scripture. [endnote 8]
Luther continues his discussion on the perspicuity of Scripture by confessing two clarities of Scripture. Luther writes
In a word: The perspicuity of Scripture is twofold, just as there is a double lack of light. The first is external, and relates to the ministry of the Word; the second concerns the knowledge of the heart. If you speak of internal perspicuity, the truth is that nobody who has not the Spirit of God sees a jot of what is in the Scriptures. All men have their hearts darkened, so that, even when they can discuss and quote all that is in Scripture, they do not understand or really know any of it. They do not believe in God, nor do they believe that they are God’s creatures, nor anything else-as Ps. 13 puts it, “The fool hath said in his heart, there is no God” (Ps. 14.1). The Spirit is needed for the understanding of all Scripture and every part of Scripture. If, on the other hand, you speak of external perspicuity, the position is that nothing whatsoever is left obscure or ambiguous, but all that is in the Scripture is through the Word brought forth into the clearest light and proclaimed to the whole world. [endnote 9]
For Luther the Holy Spirit is the interpreter of Scripture. Without the Holy Spirit, there is no understanding of the life, death, and resurrection of Jesus Christ for the forgiveness of sin. The Scriptures are also understandable concerning the will of man for the sacred writings have been clarified through the Word made flesh. Because of Christ, all things in the Scriptures are clear and therefore there is no need for the church to interpret, for the Spirit interprets and proclaims.
 Erasmus, Desiderius. Discourse on free will by Erasmus and Luther. Trans. and ed. by Ernst F. Winter. Ungar Press. New York, New York. 1961. 8
 Luther, Martin. The Bondage of the Will pg. 72
 Erasmus, Desiderius. Discourse on free will by Erasmus and Luther. Trans. and ed. by Ernst F. Winter. Ungar Press. New York, New York. 1961. 59
 Erasmus, Desiderius Discourse on free will by Erasmus and Luther. Trans. and ed. by Ernst F. Winter. Ungar Press. New York, New York. 1961. 47
 Luther, Martin. 195.
 Luther, Martin 63
 Luther, Martin 72
 Forde, Gerhard. Captivation of the will 28
 Luther, Martin. 73-74