It has been my hunch that scholars who originated the Deutero Isaiah theory in the 18th century did so because of the theological implications of prophecies, which give them hemorrhoidal levels of discomfort. To scholars with atheistic leanings, fulfilled prophecies are impossible, so they simply date the authorship of those prophecies to the time in which they were fulfilled! They let their anti-theistic presuppositions form the foundations of their theories. And they don’t even hide their motivations, which I’ll uncover in this article.
In the case of Isaiah, scholars have determined that he could not possibly have known about King Cyrus or the Babylonian exile in the 6th century B.C. during his lifetime in the 8th century B.C. so they have attributed portions of his book to an unnamed author (or authors) who lived in the 6th century B.C. The original form of this theory on Deutero Isaiah split Isaiah into chapters 1 – 39 and 40 to 66. Later versions have added more divisions. Using this formula, they can nullify all of the prophecies in the Bible except those that occurred after the closing of the Jewish canon, which the ancient Jewish historian Josephus stated in Against Apion was during Artaxerxes’ reign (around 465-425 B.C.).
They believe prophets weren’t really prophetic. Rather they were merely Godly men whose names had prestige and whose words only sparsely appear (if at all) in the texts attributed to them. They believe the Jewish Scriptures were composed over centuries by a series of named and unnamed authors. The named authors such as Jeremiah and Isaiah may have written portions of the books attributed to them – but others added to their books in a series of insertions over centuries just as one could add structures and designs to a great cathedral.
Fortunately, people carting out these fanciful notions don’t hide their anti-theistic biases, which a quotation from Ulrich Berges of the University of Bonn demonstrates. Rather than paraphrase his wording, I have quoted him below (with bold text added for emphasis).
Ulrich Berges on How Deutero Isaiah Originated
“The historical gap of more than 150 years which lies between Isaiah at the end of the 8th century and the time of the end of the exilic period presumed in Isa 40-55 (Cyrus’ decree in 539 B.C.E.), could, with the rise of the historical critical Bible interpretation, no longer be overcome merely by referring to the visionary power of Isaiah. To compound matters, Isaiah is said not only to have announced the prospect of salvation, but also to have mentioned the name of the new Persian ruler, Cyrus II (559-530) in Isa 44:28; 45:1. It was this problem which gave rise, toward the end of the 18th century, to the argument between ecclesiastical and rationalistic interpretation. This argument was not only concerned with the question as to which words can be traced back to Isaiah, but more fundamentally with the question as to what rationally comprehensible accreditation one was prepared to give to the prophets and what not. This is of utmost importance to the emergence of the Deutero-Isaiah hypothesis. Johann Christoph Döderlein (1746-1792), Professor at the Franconian University of Altdorf writes: ‘The dogmatics of Christians cannot be the dogmatics of the contemporaries of Isaiah, and where Cyrus is being described, I cannot think of the Messiah.’ He then poses the question: ‘Might it not be feasible that this entire chapter was only written down during the Babylonian exile?’ Only as late as 1789 does Döderlein formulate the thesis in the third edition of his Isaiah-commentary that the “oratio,” or rather the entire book after chapter 40 cannot be attributed to Isaiah, but that it was written at the end of the exilic period by an anonymous, or rather a homonymous prophet. Because of this, Johann Christoph Döderlin is considered to be the discoverer of Deutero-Isaiah, and justifiably so, for in so doing he found middle ground between the rational and the orthodox view. The solution was as simple as it was brilliant: Isa 40-55 was not written by Isaiah ben Amoz, but rather by an inspired prophet whose name and identity, however, remained unknown.”
He Let the Cat is Out of the Bag
If his reasoning wasn’t crystal clear, let me put it another way. These people have allowed their anti-theist presuppositions to cloud their scholarship, which has fogged the windows of Biblical knowledge for over two hundred years.
SJ Thomason is a Christian business professor who teaches courses on human resource management, leadership, cultures, and communication. This article is a portion of a chapter in a new book she’s working on, which should be completed in coming months.
  Berges, U. (2010). The book of Isaiah as Isaiah’s book: the latest developments in the research of the prophets. Old Testament Essays, 23(3).
 Berges, U. (2010). The book of Isaiah as Isaiah’s book: the latest developments in the research of the prophets. Old Testament Essays, 23(3).