Now, when we come to chs. xl.-lxvi., we find that, occurring in a book which we have just seen no reason for supposing to be in every part of it by Isaiah, these chapters nowhere claim to be his. They are separated from that portion of the book, in which his undisputed oracles are placed, by a historical narrative of considerable length. And there is not anywhere upon them nor in them a title nor other statement that they are by the prophet, nor any allusion which could give the faintest support to the opinion, that they offer themselves to posterity as dating from his time. It is safe to say, that, if they had come to us by themselves, no one would have dreamt for an instant of ascribing them to Isaiah; for the alleged resemblances, which their language and style bear to his language and style, are far more than overborne by the undoubted differences, and have never been employed, even by the defenders of the Isaian authorship, except in additional and confessedly slight support of their main argument, viz. that the chapters must be Isaiah's because they are included in a book called by his name.
Let us understand, therefore, at this very outset, that in discussing the question of the authorship of "Second Isaiah," we are not discussing a question, upon which the text itself makes any statement, or into which the credibility of the text enters. No claim is made by the Book of Isaiah itself for the Isaian authorship of chs. xl.-lxvi.
A second fact in Scripture, which seems at first sight to make strongly for the unity of the Book of Isaiah, is that in the New Testament, portions of the disputed chapters are quoted by Isaiah's name, just as are portions of his admitted prophecies. These citations are nine in number.[3] None is by our Lord Himself. They occur in the Gospels, Acts and Paul. Now if any of these quotations were given in answer to the question, Did Isaiah write chs. xl.-lxvi. of the book called by his name? or if the use of his name along with them were involved in the arguments which they are borrowed to illustrate (as, for instance, is the case with David's name in the quotation made by our Lord from Psalm cx.), then those who deny the unity of the Book of Isaiah would be face to face with a very serious problem indeed. But in none of the nine cases is the authorship of the Book of Isaiah in question. In none of the nine cases is there anything in the argument, for the purpose of which the quotation has been made, that depends on the quoted words being by Isaiah. For the purposes, for which the Evangelists and Paul borrow the texts, these might as well be unnamed, or attributed to any other canonical writer. Nothing in them requires us to suppose that Isaiah's name is mentioned with them for any other end than that of reference, viz., to point out that they lie in the part of prophecy usually known by his name. But, if there is nothing in these citations to prove that Isaiah's name is being used for any other purpose than that of reference, then it is plain--and this is all that we ask assent to at the present time--that they do not offer the authority of Scripture as a bar to our examining the evidence of the chapters in question.
