The Authorship and Unity of Isaiah

This is a paper I wrote for one of my Old Testament seminary classes. I was given a range of topics and picked Isaiah simply because I wanted an excuse to bolster my personal library with some commentaries on Isaiah. It actually ended up being a very eye opening assignment for me and probably one of my favorites so far in seminary.


The Authorship and Unity of Isaiah

by Matthew McNutt, May 4, 2014

Table of Contents



Isaiah 1-39

Isaiah 40-55

Isaiah 56-66






Isaiah, one of the cornerstone books of both the Old and New Testaments, presents many challenges to the Biblical student. Questions about authorship, inspiration and unity of the book itself have been the subject of debate for centuries, in particular recent decades. With its prophetic nature, the book of Isaiah provides much theological insight. At the same time, with the accuracy of some of the statements, it has long been the target of accusation regarding the timing of its writing – questioning whether or not it was truly written as prophecy, or documented after the events foretold and presented as though it had been written before. This paper will explore the authorship of Isaiah, whether or not it was written by Isaiah, or Isaiah and a mix of others, and in so doing tackle the question of whether or not this impacts the validity of its inspiration and message. Ultimately, it will be demonstrated that regardless of authorship, Isaiah has authority as the Word of God and presents a unified message, within itself and with scripture in general.


For centuries it was assumed that the book of Isaiah was written by its namesake. There were questions at the varying writing styles found in the book, and even the seemingly different time frames referenced, but a literal reading and acceptance of scriptures was the traditional approach and so that is how it was accepted. After all, no other book in the Bible is written in this way[1]. Granted, while books like Psalms do have multiple authors, it is noted within the text and not presented as though one author had written the entirety of it.

In the late 1800’s, B. Duhm changed the conversation dramatically when he presented the first serious commentary to claim multiple authors.[2] He proposed three major divisions in Isaiah, based on the timeframe they seemed to be written in, and the varying writing styles; chapters 1-39, chapters 40-55, and chapters 56-66.[3] This opened the door to serious conversation and debate.

While the book of Isaiah only claims “Isaiah son of Amoz” of Jerusalem as author[4], scholars noticed a lack of historical references after chapter 39. There was also the challenge of explaining stylistic and vocabulary differences between chapters 1-39 and 40-66, as well as the Persian emperor Cyrus being named a hundred years before his birth (if Isaiah was the sole author). While it could be a true prophecy in which Isaiah foretold of someone’s birth to that level of detail, it does not fit the pattern of scripture and prophecy, nor does Cyrus seem to be that critical of a player in the narrative to warrant that kind of detail. In this instance, multiple authors spanning the centuries makes more sense. In addition, chapters 40-66 seemed to be addressed to people in the exilic period, which would have been long after Isaiah’s death.[5] Eventually, the debate over these observations culminated in three major interpretations[6]:

  1. Based on typical contemporary historical-critical reconstruction, Isaiah was written in three parts, with an unknown number of individuals (some suggest more than 10) involved in putting together what is currently present in the Bible.
  2. Isaiah may not have been involved in writing the book at all; the Babylonian Talmud claims that Hezekiah and his colleagues wrote it (as well as other books of the Bible).
  3. A single author. 2 Peter1:20-21 states that “no prophecy of Scripture came about by the prophet’s own interpretation. For prophecy never had its origin in the will of man, but men spoke from God as they were carried along by the Holy Spirit,” which some interpret to mean that God inspired and spoke through one person who then wrote Isaiah.

A natural consequence of this debate over authorship led some to being to argue over which parts are genuine and which parts are not[7]. Questions as to whether or not Isaiah is dependable began to arise. Over the last few decades, the focus has shifted more towards an emphasis of there being primary authors, as well as others who edited, or accumulated the various writings that make up the Isaiah of the canon.

While it is understandable that some would be reluctant to acknowledge the possibility of multiple authors over a span of time out of fear that it may somehow lessen the strength of the Bible or the validity of Isaiah, especially in light of past accusations that Isaiah’s prophecies had to have been written after the time of Christ of to explain their accuracy. Perhaps seeming to admit to one part of the belief would somehow invalidate so much more, perhaps a history of rejecting this theory plays into that attitude. One of the great discoveries of the past century for Biblical scholarship was the Dead Sea Scrolls from the Qumran community, in which full copies of Isaiah, virtually matching what was already in hand, were discovered and dated to a hundred years before the time of Christ[8]. This discovery documented two critical points; first, that prophecies of Christ were documented before the time of Christ, and secondly, that the editing, or modifying of Isaiah was limited to a specific window of time as the Qumran copies virtually matched all copies discovered from after the time of Christ.

Isaiah 1-39

The first portion of Isaiah is frequently attributed directly to the prophet Isaiah, or to disciples under his training who documented his teaching. The style of the first 39 chapters is somewhat of a narrative flow. It begins with a preface to the work itself in the first five chapters, then moves on to four major narratives; parable, application, consequence, and the reality that nothing more could be done.[9] From there, chapters 31-39, Isaiah moves into prophecy.

There is significant disagreement over whether or not chapters 1-39 were written completely in isolation from 40-66, or if there was influence from one to the other, or even in both directions as later scribes functioned in a redactional mode.[10] In reality, much of that debate is purely speculative, as there is no evidence one way or the other, and there is also no evidence of a group of scribes, or school of Isaiah that would have performed the edits so many believe happened.

Isaiah 40-55

According to Brevard Childs, there are three major arguments for crediting different authors from the sixth century BC for the remaining chapters of Isaiah (as opposed to eighth century BC for Isaiah 1-39):[11]

  1. Chapters 40 and after appear to be set in the exilic period after the fall of Jerusalem in 587 BC.
  2. The differences in language, style, and even concepts are so strong that the most logical explanation is a different author.
  3. The level of detail in chapters 40 on are such that if an eighth century BC prophet spoke them it would be beyond anything else in the Bible in its precision.

While scholars wanted to avoid further fragmenting Isaiah, many feel there is a particular unity in chapters 40-55 that set it apart from the other two portions of Isaiah.[12] As referenced earlier, Duhm was a significant influence in bringing this line of thought to the front. As they further studied and researched it, the oral patters of prophetic speech made it undeniable to some that this second part of Isaiah was written separately from the earlier and later portions.[13]

Isaiah 56-66

Childs introduces this third portion of Isaiah following Duhm’s model and rational.[14] Duhm dated it shortly before the period of Nehemiah, and viewed these last eleven chapters as a collection of different texts brought together by an unknown individual or an unknown team of people. Further, Childs feels that the relationship between the second and third portions of Isaiah is what defines their need to be considered separate.[15] While it does fit with the message and overall thrust of Isaiah, the seeming style of being a collection of writings collected together requires a different classification. It is a strong enough shift in style to warrant the ongoing debate over its origins.


One of the logical next questions, if Isaiah is indeed written by a number of individuals while purporting to be written by one, is it truly inspired? Can it be trusted as scripture from God? It is fascinating to note that the New Testament authors and Christ Himself quoted from Isaiah more than all the other prophets combined, certainly seeming to display their confidence in the inspiration of Isaiah.[16] While the various authors using Isaiah as authoritative lends support to its inspiration, the use of Isaiah by Christ, God Himself, certainly should carry weight in any debates regarding the confidence that can be placed in Isaiah.

In fact, The United Bible Society’s Greek New Testament estimates over four hundred quotes, paraphrases, and allusions to the book of Isaiah throughout the New Testament.[17] If believers hold to the belief that the New Testament is inspired, by virtue of heavy reliance on Isaiah alone a measure of confidence in the inspiration of Isaiah should be understood. While scholars today may struggle with some of these issues, it was unquestionably accepted in both the Old and New Testaments as truth.[18]

The apostle Paul was a significant force for using Isaiah.[19] For example, in 2 Corinthians 6:1-2, Paul quotes Isaiah 49:8. What’s fascinating is how Paul quotes Isaiah, attributing the very words to God, not the prophet. In Paul’ view, Isaiah may have been brought into existence through a man, but the words were very much from God – an undeniable support of inspiration. Paul’s focus in using Isaiah generally was in support of him defending his theology through biblical interpretation – in effect, Paul is often times making, or arguing a case, and uses Isaiah as the evidence proving it.[20] From his perspective, its reliability was unquestioned.

Schultz notes in his article some of the differing views on inspiration of Isaiah, and while they each seem to come at it from different standpoints, they all still arrive at the conclusion that it is indeed inspired. For example[21]:

How does Meade understand inspiration in Isaiah? According to his analysis, each of the individual prophetic figures who contributed to First, Second and Third Isaiah were equally conscious of inspiration and of participating in the council of Yahweh. Their legitimizing ‘call’ narratives (found in Isaiah 6, 40, and 61, respectively) serve to affirm ‘their participation in an ongoing revelation and their dependence on previous revelation.’ Why do Second and Third Isaiah remain anonymous? Because they both claim to be ‘part of one revelation and one tradition, whose recognized head is Isaiah of Jerusalem.’ Inspiration guarantees that their reinterpretations of Isaiah’s words in order to actualize them (i.e., to make them apply to later audiences) will cause Isaiah of Jerusalem’s prophecies to speak to future generations just as he originally had intended.

Schultz later observes that the emphasis in determining inspiration in recent decades is moving away from a vertical perspective, that is, a direct relationship between author and God alone, in which case knowing the identity of the author does become more urgent. His observation is that it is instead becoming a vertical relationship in regards to inspiration; that God inspires the author, and then continues to inspire those who contribute or edit, as well as the readers themselves to give His word power generation after generation.[22]

Ultimately, having stood the test of time, with clear support from biblical authors following Isaiah, as well as apparent support from Christ Himself, it would seem that the book of Isaiah, in spite of questions about its authorship, is not questioned on the issue of inspiration. Childs said it well in concluding his writings on this particular topic when he wrote that the scriptures “receives its true meaning within a specific context in which its message is proclaimed and received in the obedience of faith. When seen in the light of this confessional stance, the Bible’s authority provides an essential and foundational feature of Christian exegesis. Thus, interpreters of Isaiah … could affirm that the prophet’s meaning was at times hidden and obscure, yet its authority was never compromised or rendered inoperative by the working of the Spirit.”[23]


Initially, with the debate on the authorship of Isaiah swelling, many saw Isaiah becoming more and more fragmented, with very little unity.[24] With the focus on writing styles and theories of different authors, the overall message and thrust of the book was seemingly lost sight of for some time. However, in recent decades the pendulum seems to be swinging back to a more balanced view in theological circles as more and more are accepting the overall unity of the book of Isaiah.[25]

Shultz notes that the “transmitters of Isaiah’s words so closely identify themselves with him in their self-understanding that they are simply expounding, clarifying, systematizing, extending and applying his message in terms of their own later setting. Thus, their creative new interpretations are correctly described as Isaianic.”[26] The various authors were so dedicated to the message of Isaiah, and with the inspiration of God, that in spite of their differences in style that have been noticed there is still a thematic unity that shines through when one steps back and looks at the full picture.[27]

In his commentary, Childs questions whether or not the issue of multiple authors is even actually an issue; his primary concern is in preserving the unity of Isaiah which he claims rings true through all 66 chapters. He sees no conflict in later chapters being authored by others as Isaiah himself does not make an appearance after chapter 39.[28] Over and over, Childs stresses that when the reader steps back and looks at the whole picture, rather than focusing on the details, the unity between all three sections tell a unified message of a “coming, eschatological change brought about by divine intervention.”[29] Consequently, he cautions against engaging in too much speculative theory about the nature of Isaiah when its primary value is in its message, which holds true regardless of which author theory one holds to.[30]

The Bible as a whole maintains its integrity as a unified collection of books, writings, and letters, in spite of being gathered over a tremendous amount of time and authored by many individuals from different times, cultures and languages.[31] When that is taken into consideration, it is not so hard to accept the apparent unity of Isaiah in spite of a handful of possible authors over the course of two centuries. God is still able to inspire and preserve His message regardless of the manner in which it is transmitted and recorded. Shultz rightfully reminds readers that we are intended “to read Isaiah 1-66 as ‘a book concerned with Isaiah in its entirety.’”[32]


In spite of compelling arguments suggesting multiple authors for Isaiah, it is evident that whether or not Isaiah himself wrote and/or dictated every word of the book, it is still Isaiah’s message, given from God. Through it all, God’s hand is seen working, shaping, and molding this book of Isaiah as beneficial and necessary for believers today. Whether through His divine protection of the recording of the book – keeping it virtually intact word for word over the course of millennia – or through the affirmation of Isaiah’s authority as inspired scripture through repeated support throughout the New Testament and from Christ Himself, Isaiah is a unified, inspired, authoritative part of the canon of scriptures. Even within the book itself there are connecting measures, found through looking at chapters 65 and 66 which form a type of bracket around the book with chapter one, or even the connections between the three volumes contained within Isaiah.[33] It is a critical, indispensable part of God’s word to man.


Bacote, Vincent, ed., and Laura C. Miguelez, ed., and Dennis L. Okholm, ed. Evangelicals & Scripture: Tradition, Authority and Hermeneutics. Downers Grove, IL: InterVarsity Press, 2004.

Childs, Brevard S. The Old Testament Library: Isaiah. Louisville: Westminster John Knox Press, 2001.

Childs, Brevard S. The Struggle to Understand Isaiah as Christian Scripture. Grand Rapids: Wm. B. Eerdmans Publishing Co., 2004.

Enns, Peter. Inspiration and Incarnation: Evangelicals and the Problem of the Old Testament. Grand Rapids: Baker Academic, 2005.

Motyer, J. Alex. Tyndale Old Testament Commentaries: Isaiah. Downers Grove, IL: IVP Academic, 1999.

Oswalt, John N. The NIV Application Commentary: Isaiah. Grand Rapids: Zondervan, 2003.

Walton, John H. Ancient Near Eastern Thought and the Old Testament. Grand Rapids: Baker Academic, 2006.

[1] Oswalt, John N., The NIV Application Commentary: Isaiah, (Grand Rapids: Zondervan, 2003), 18.

[2] Childs, Brevard S., The Old Testament Library: Isaiah, (Louisville: Westminster John Knox Press, 2001), 1.

[3] Ibid., 1.

[4] Isaiah 1:1, 2:1

[5] Oswalt, Isaiah, 33.

[6] Bacote, Vincent, ed., and Laura C. Miguelez, ed., and Dennis L. Okholm, ed., Evangelicals & Scripture: Tradition, Authority and Hermeneutics, (Downers Grove, IL: InterVarsity Press, 2004), 150.

[7] Childs, Isaiah, 2.

[8] Childs, Brevard S., The Struggle to Understand Isaiah as Christian Scripture, (Grand Rapids: Wm. B. Eerdmans Publishing Co., 2004), 4.

[9] Motyer, J. Alex, Tyndale Old Testament Commentaries: Isaiah, (Downers Grove, IL: IVP Academic, 1999), 47.

[10] Childs, Isaiah, 7.

[11] Ibid., 289.

[12] Ibid., 290.

[13] Ibid., 290.

[14] Ibid., 440.

[15] Ibid., 441.

[16] Motyer, Isaiah, 39.

[17] Childs, Struggle to Understand Isaiah, 5.

[18] Walton, John H., Ancient Near Eastern Thought and the Old Testament, (Grand Rapids: Baker Academic, 2006), 94.

[19] Enns, Peter, Inspiration and Incarnation: Evangelicals and the Problem of the Old Testament, (Grand Rapids: Baker Academic, 2005), 135.

[20] Childs, Struggle to Understand Isaiah, 17.

[21] Bacote, Evangelicals & Scripture, 157.

[22] Ibid., 160.

[23] Childs, Struggle to Understand Isaiah, 302.

[24] Childs, Isaiah, 2.

[25] Bacote, Evangelicals & Scripture, 154.

[26] Ibid., 156.

[27] Ibid., 165.

[28] Childs, Isaiah, 7.

[29] Ibid., 442.

[30] Ibid., 445.

[31] Childs, Struggle to Understand Isaiah, 312.

[32] Bacote, Evangelicals & Scripture, 169.

[33] Childs, Isaiah, 447.

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