Until the late eighteenth-century A.D., the overwhelming majority of Jewish and Christian interpreters believed that Isaiah, the son of Amoz, who ministered in Jerusalem during the eighth century B.C., authored the entire book that bears his name. However, German historical-critical scholars Julius Döderlein (1789), Johann Eichhorn (1783), and Wilhelm Gesenius (1819) began to conjecture that Isaiah 1-39 and 40-66 were two separate works written by two different authors about 150 years apart. These scholars did not believe in the supernatural claims of the Bible because they had been influenced by the Enlightenment. Due to their anti-supernatural presuppositions, they rejected the biblical teaching that Scripture was inspired by God (cf. 2 Timothy 3:16; 2 Peter 1:21). As a result, many proponents of this view claimed that Isaiah 1-39 and 40-66 had to be from two separate authors because 1) the internal evidence appeared to show that chapters 40-66 was written in the Babylonian exile, 2) the style between both sections appear to be different (i.e., the writing in chapters 1-39 is terse and solemn while chapters 40-66 are more developed and its ethos warm and passionate), and 3) the theological viewpoints appear to be different in both sections.
Each of the reasons for propagating that an alleged “Deutero-Isaiah” anonymously wrote chapters 40-66 during the exile, however, is unconvincing. The internal evidence actually supports the view that Isaiah received the entire contents of the book as a direct revelation from God and had prophesied of the coming Babylonian exile in Isaiah 1-39 such as in 1:7-9; 5:13; 14:1-4; and 35:1-4, just as it is in chapters 40-55. Moreover, the argument alleging different writing styles falsely assumes that a writer may not change his writing style when he addresses a different subject or that a writer’s style may not change over time, especially since Isaiah prophesied for over 40 years. And finally, the theological argument is completely subjective because the purpose of chapters 1-39 deal mostly with God’s judgment against Judah and the nations, whereas chapters 40-66 emphasized God’s consolation. Therefore, the differences between the two sections with respect to their theological themes are plainly related to the book’s overall argument and not to a hypothetical second author.
One of the main reasons that critical scholars denied that Isaiah wrote chapters 40-66 is because Cyrus is mentioned about 150 years before he came on the scene. Again, they made this claim because they disallowed supernatural miracles and divine intervention, as well as alleging that prophecy did not function that way because prophets always addressed their contemporaries. Instead, they drew upon the principle of vaticinium ex eventu (Latin: “prophecy from the event”) because it explains how Cyrus’ name could be recorded in Isaiah 44:28 and 45:1 without resorting to divine inspiration. The principle conveniently circumvents any talk of divine intervention and, ultimately, makes biblical prophecy fraudulent since it was written after the prophesied event had already taken place which would make it a deceitful, blatant lie.
This wrong-headed assertion, however, does not satisfy all of the prophetic data contained in the book. It does not account for the fact that the Suffering Servant is none other than Jesus Christ, who fulfilled Isaiah 52:13-53:12 to the letter—not to mention many other messianic prophecies that He fulfilled from the book of Isaiah, such as in 7:14; 9:6; 11:1-2; 49:6; and 61:1-3. Furthermore, Isaiah prophesied of the millennial reign of Christ as well as the New Jerusalem in the New Heavens and New Earth in passages such as 2:1-5; 4:2-6; 9:7; 60:10-22; and 65:17-25. These passages have their counterparts in other prophetic texts such as the book of Revelation. For example, compare Isaiah 60:10-22 with Revelation 21:22-27. The Prophet Isaiah and the Apostle John saw the same vision regarding the New Jerusalem. Therefore, the fact that Cyrus is mentioned by name is not the only prophecy in Isaiah that the critics have to deal with. They must also explain why the prophecies related to Christ as the Suffering Servant (as confirmed in Acts 8:26-36) and the New Jerusalem are also in the book. What is patently clear is that their explanations are reductionistic and woefully insufficient because they do not fully account for the entire prophetic data nor their future fulfillment.
A better way to understand the data is to see the argument contained in chapters 40-66. Passages such as Isaiah 40:18-28; 41:21-25; 42:8-9; 43:10; 44:6-45:7; and 46:18-22, all address the LORD, as the sovereign God over the nations and their idols. In these key texts, God challenges the false gods/idols to a contest. For example, in Isaiah 41:21-29, the LORD demands that the idols tell the future. They cannot because they are less than nothing, but He alone can tell the future and of the coming of Cyrus:
“Present your case,” says the LORD. “Set forth your arguments,” says Jacob’s King.
“Tell us, you idols, what is going to happen. Tell us what the former things were, so that we may consider them and know their final outcome. Or declare to us the things to come, tell us what the future holds so that we may know that you are gods. Do something, whether good or bad, so that we will be dismayed and filled with fear. But you are less than nothing and your works are worthless; whoever chooses you is detestable. So I have stirred up one from the north, and he comes [i.e., Cyrus of Persia]—one from the rising sun who calls on my name. He treads on rulers as if they were mortar, as if he were a potter treading the clay. Who told of this from the beginning so we could know, or beforehand, so we could say, ‘He was right’? No one told of this, no one foretold it, no one heard any words from you. I was the first to tell Zion, ‘Look, here they are!’ I gave to Jerusalem a messenger of good news [i.e., Isaiah]. I look but there is no one—no one among the gods to give counsel, no one to answer when I ask them. See, they are all false! Their deeds amount to nothing; their images are but wind and confusion.”
After Isaiah prophesied of the Persian king, Cyrus, by name in 44:28 and 45:1, 13 regarding what His “anointed” will do in rebuilding Jerusalem (44:26, 28; 45:13), the temple (44:28), and restoring His people to Judah (45:13), the LORD once again challenged the false gods/idols:
“Assemble yourselves and come; draw near together, you survivors of the nations!
They have no knowledge who carry about their wooden idols, and keep on praying to a god that cannot save. Declare and present your case; let them take counsel together!
Who told this long ago? Who declared it of old? Was it not I, the LORD? And there is no other god besides me, a righteous God and a Savior; there is none besides me.”
Thus, it is evident that within the argument of the book that chapters 40-66 address the future exiles in Babylon in order to declare to them hope and comfort because the LORD had forecasted for them a coming “anointed one,” named Cyrus, who will release them from their captivity and assist them in the rebuilding of Jerusalem and its temple. God also declares that only He can prophesy of future events and people—naming them by name (!)—because there are no other gods, but Him alone. The sovereign LORD, however, does not stop there. He goes on to foretell of the coming “Suffering Servant” in Isaiah 52:13-53:12 who will be a substitutionary atonement for us as well as describing the forthcoming New Jerusalem and the New Heavens and New Earth in Isaiah 60:10-22 and 65:17-25. The context of the book, thus, matches the superscription of Isaiah 1:1 and the single call narrative in the entire book which appears in Isaiah 6. There was only one prophet that God called in the book of Isaiah, and he alone saw the vision recorded in the book that the LORD had given him during the reigns of Uzziah, Jotham, Ahaz, and Hezekiah, kings of Judah.
Eugene H. Merrill, Mark F. Rooker, Michael A. Grisanti, The World and the Word (Nashville, TN: B&H Academic, 2011), 367.
 Ibid., 368.
 Ibid., 369-70. The arguments for this section are from Mark Rooker in the pages noted.
The Latin phrase is translated “prophecy from the event,” meaning that the prophecy was written after the event had already occurred.
Note that the man of God in 1 Kings 13 also prophesied of King Josiah by name and gave specific details regarding what he would do centuries before he came on the scene (cf. 2 Kings 23:16-18).