The Encyclopedia Britannica expresses the almost unanimous verdict of critics respecting the authorship of the four principal historical books of the Old Testament: “We cannot speak of the author of Kings or Samuel, but only of an editor or successive editors whose main work was to arrange in a continuous form extracts or abstracts from earlier books.”

Isaiah.

Isaiah, the chief of the prophetic books, and, next to the Pentateuch and the Four Gospels, the most important book of the Bible, purports to be a series of prophecies uttered during the reigns of Uzziah, Jotham, Ahaz, and Hezekiah. Uzziah’s reign began B.C. 810, and ended B.C. 758; Hezekiah’s reign began B.C. 726 and ended B.C. 698. Isaiah’s ministry is supposed to have extended from about 760 to 700 B.C., and toward the close of this period, the book of Isaiah, as it now appears, is said to have been written.

In support of Isaiah’s authorship of the entire work the following arguments have been advanced:

The above arguments for the authenticity of the work are partly true and partly untrue. So far as they conflict with the following arguments against its authenticity as a whole they are untrue:

Isaiah might very properly be divided into two books, the first comprising the first thirty-nine chapters; the second, the concluding twenty-seven chapters. Impartial critics agree that while Isaiah may have written a portion of the first part he could not have written all of it nor any of the second. This is the conclusion of Cheyne, Davidson, De Wette, Eichorn, Ewald, Gesenius, and others.

That he wrote neither the first nor the second part of the book, as it now exists, is proven by the following passages taken from both: