What evidence leads to the conclusion that the Book of Isaiah includes material by more than one author?

For many Christians, the authorship and unity of the Book of Isaiah has for long remained to be a sensitive issue for most part of the 20th century. This specific matter has been able to come to an unbalanced and large amount of discussion has brought up more heat than light. For most of the people, it has become a form of orthodoxy, which takes stand on issues sorting out those who do not believe in Bible and those who do. There are numerous reasons to the issue regarding why the unity and authorship of the book of Isaiah has become a combat for some people, and in the course of doing so, one issue appears in the forefront quickly and invariably: the issue of predictive prophecy. We, as human beings, often make the assumption that the title of the book tells us regarding the author of the entire book. However, the conventions title of the Bible does not communicate to the human beings, or its followers, anything regarding its authorship. Merely the fact that the book is titled "Isaiah" does not make any implication in any way about who wrote the complete book. There are numerous assumptions that the books that have a single title are necessarily the work of one person.

From numerous angles of concern and in various degrees of intensity, the protectors and opponents of the single authorship and unity of Isaiah challenge that, it was over a long period of time that the book was conceded, and this is likely to eradicate the surprisingly precise analytical component of prediction in the book. Sometimes, there are even claims made by the individuals, that those people who recommend or suggest anything that is different from the already existing one, are striving to foster an agenda which refuses the belief in the trustworthiness or prophecy of the Scripture (Dennis, 2011). To put it the other way, they make the claim that the entire book was written by the Isaiah of Jerusalem, and whatever he predicts could be nothing else but direct revelation from God. To the people, this provides the proof that the Scripture is of the supernatural origin, along with the evidence that there can be absolute future prediction for the happenings hundreds of years in advance.

The Book of Isaiah is the first and longest of the books of the Major Prophets in the Old Testament of the Bible. It derives its name from the prophet Isaiah, who lived in Jerusalem, perhaps of aristocratic origin. His prophetic career spanned half a century, from around 742 BC to at least 701. This book, however, contains the work of more than one man.

We, as human beings, often make the assumption that the title of the book tells us regarding the author of the entire book. However, the conventions title of the Bible does not communicate to the human beings, or its followers, anything regarding ...