The Deutero-Isaiah theory is an idea in biblical scholarship that proposes the Book of Isaiah was written by two or more authors rather than just one. According to this theory, there were at least two major authors who contributed to the book of Isaiah. The first author is known as the prophet Isaiah who lived in the 8th century BCE. This author wrote chapters 1-39 of the Book of Isaiah. The second author is an anonymous writer who lived during the 6th century BCE, after the Babylonian exile. This second author wrote chapters 40-55 of Isaiah and is commonly called “Deutero-Isaiah” or “Second Isaiah.” Some scholars even propose a third author for chapters 56-66, referring to this person as “Trito-Isaiah.”
The Deutero-Isaiah theory emerged in the late 1700s from biblical scholarship in Germany. Up until this point, it was traditionally believed that the prophet Isaiah wrote the entire book himself in the 8th century BCE. However, German scholars began to notice differences in style, language, themes, and historical references between the first 39 chapters and the last 26 chapters. Based on these perceived differences, they theorized the book of Isaiah had multiple authors writing at different times.
One of the main reasons for this theory is that chapters 40-55 of Isaiah assume that the Babylonian exile has already occurred. The exile took place from 586-539 BCE when the Babylonians conquered Jerusalem and forced many Judeans into captivity in Babylon. Isaiah 1-39 contains prophecies about the coming exile, while Deutero-Isaiah addresses people already in exile and prophesies their return to Judah.
For example, Isaiah 39:6-7 predicts the Babylonian captivity: “Behold, the days are coming, when all that is in your house, and that which your fathers have stored up till this day, shall be carried to Babylon. Nothing shall be left, says the Lord. And some of your own sons, who will come from you, whom you will father, shall be taken away, and they shall be eunuchs in the palace of the king of Babylon.”
Meanwhile, Isaiah 43:14 declares that God will bring back the exiles from Babylon: “Thus says the Lord, your Redeemer, the Holy One of Israel: For your sake I send to Babylon and bring them all down as fugitives, even the Chaldeans, in the ships in which they rejoice.”
These references indicate Deutero-Isaiah was written after the fall of Jerusalem when many Judeans were already exiled in Babylon. The author is prophesying and comforting those in captivity about their future release. Isaiah 1-39, on the other hand, warns the people before the exile occurs.
In addition to historical situation, there are differences in style and vocabulary between the sections. Isaiah 1-39 contains more poetic expression, metaphors, and appeals to Israel’s covenant with God. Isaiah 40-55 has less poetry and more prose in the form of a prophetic message. There are certain words and phrases that appear often in Deutero-Isaiah but rarely or never in Isaiah 1-39.
For instance, the phrase “the Holy One of Israel” is used 12 times in Isaiah 40-55 but only 6 times in chapters 1-39. References to Israel as the “Servant of the Lord” also appear much more frequently in Deutero-Isaiah. These types of variations suggest the sections were written by different authors.
The unity of the book of Isaiah was traditionally accepted until the late 18th century when German scholars like J.C. Doderlein and J.G. Eichorn began questioning Isaiah’s sole authorship. Over the next 200 years, the Deutero-Isaiah theory became widespread as more academics analyzed the book’s content and style.
Today, most mainstream biblical scholars accept the multiple authorship of Isaiah although there are some dissenting views. Conservative Christian scholars tend to reject the Deutero-Isaiah theory and argue that Isaiah wrote the entire book himself as traditionally thought.
While authorship remains debated, most scholars emphasize the importance of reading Isaiah as a whole. They may acknowledge multiple authors but still see a unified message and common themes across all 66 chapters.
Evidence for Multiple Authorship of Isaiah
Scholars point to the following evidence that the Book of Isaiah has multiple authors writing at different points in Israel’s history:
Differences in Historical Background
Isaiah 1-39 reflects the geopolitical situation in the 8th century BCE when Assyria was the main threat against Jerusalem. Isaiah 40-55 shifts focus to the 6th century BCE with the Babylonian exile and return from exile. This change in historical background suggests two different time periods for the authors.
Literary Style
Isaiah 1-39 contains poetic, vivid oracles while Isaiah 40-55 has longer passages of prose and repetition. The later chapters are less poetic and more liturgical.
Themes
Earlier chapters emphasize Judah’s sin and need for purification while later chapters focus on redemption and consolation. There is a shift from threat language to salvation language between the sections.
Vocabulary Differences
Certain words and phrases like “Holy One of Israel” occur more often in Isaiah 40-66. The name Isaiah also appears more in 1-39 then disappears in 40-55 before returning in 56-66.
Cyrus the Persian
Isaiah 44-45 prophesies about Cyrus freeing the Jews from Babylon. He is called God’s anointed. But Cyrus lived after Isaiah’s time in the 6th century BCE.
Arguments Against Multiple Authorship
While most scholars believe in multiple authors, there are opposing views. Here are some arguments for the unity of Isaiah and single authorship:
Manuscript Tradition
The earliest Isaiah manuscripts we have make no distinction between sections and present the book as one singular text.
New Testament Quotes
New Testament authors quote from both sections of Isaiah but attribute them all to Isaiah himself.
Thematic Unity
There are common themes about God’s mercy and salvation that tie the whole book together. Some see a unified message.
Possibility of Prediction
Some argue Isaiah could have supernaturally predicted Babylonian captivity and Cyrus the Persian before they happened.
Lack of Historical Precision
Names and places in Deutero-Isaiah’s prophecies are vague which suggests he didn’t have precise historical knowledge of the exile.
Implications of the Deutero-Isaiah Theory
This theory has significance for understanding when the book of Isaiah was written, interpreting its prophecies, and applying higher criticism to the Bible. Here are some implications:
Later Date of Writing
Multiple authors would mean the last 26 chapters were written 100-150 years after Isaiah’s time in the 6th century BCE rather than the 8th century.
Prophecy After the Fact
Predictions about Cyrus and exile may have been written after the events happened which changes how prophecy is understood.
Development of Messianic Ideas
Deutero-Isaiah enlarges the messianic role and introduces the idea of God’s suffering servant. This shows a development in theological concepts over time.
Higher Criticism of the Bible
This theory opened the door for scholars to analyze biblical books as human literary products with multiple authors and sources. This led to rethinking traditional views of authorship.
Key Passages Attributed to Deutero-Isaiah
Some important prophecies and themes from Isaiah 40-55 thought to be authored by Deutero-Isaiah include:
Isaiah 40: Comfort for God’s People
“Comfort, comfort my people, says your God. Speak tenderly to Jerusalem, and cry to her that her warfare is ended, that her iniquity is pardoned.” (Isaiah 40:1-2)
This passage indicates God’s compassion and the end of exile judgement.
Isaiah 42: The First Servant Song
“Behold my servant, whom I uphold, my chosen, in whom my soul delights.” (Isaiah 42:1)
This introduces the “servant of the Lord” motif found throughout Deutero-Isaiah.
Isaiah 43: Redeemer of Israel
“I, I am he who blots out your transgressions for my own sake, and I will not remember your sins.” (Isaiah 43:25)
God promises redemption and forgiveness for exiled Israel.
Isaiah 49: The Second Servant Song
“And now the Lord says, he who formed me from the womb to be his servant.” (Isaiah 49:5)
Further develops the identity and mission of the servant.
Isaiah 53: The Fourth Servant Song
“But he was pierced for our transgressions; he was crushed for our iniquities.” (Isaiah 53:5)
This passage about the suffering servant is quoted in the New Testament to refer to Jesus.
Isaiah 55: An Invitation to Grace
“Come, everyone who thirsts, come to the waters; and he who has no money, come, buy and eat!” (Isaiah 55:1)
A concluding invitation to receive God’s gift of grace.
Conclusion
The Deutero-Isaiah theory proposes that at least two distinct authors contributed to the book of Isaiah. Isaiah 1-39 is attributed to the original prophet while Isaiah 40-55 is ascribed to an anonymous 6th century BCE writer known as Deutero-Isaiah. This theory developed from analyzing differences in language, style, themes and historical background between the two sections. Scholars debate whether it diminishes or enhances interpretation of the book. While authorship continues to be studied, Isaiah remains an essential prophetic book in the Bible with a lasting message of judgement, redemption and hope.