Of course, any chronological arrangement of Isaiah's prophecies must be largely provisional. Only some of the chapters are fixed to dates past possibility of doubt. The Assyriology which has helped us with these must yield further results before the controversies can be settled that exist with regard to the rest. I have explained in the course of the Exposition my reasons for the order which I have followed, and need only say here that I am still more uncertain about the generally received dates of chaps x. 5-xi., xvii. 12-14 and xxxii. The religious problems, however, were so much the same during the whole of Isaiah's career that uncertainties of date, _if they are confined to the limits of that career_, make little difference to the exposition of the book.
Isaiah's doctrines, being so closely connected with the life of his day, come up for statement at many points of the narrative, in which this Exposition chiefly consists. But here and there I have inserted chapters dealing summarily with more important topics, such as The World in Isaiah's Day; The Messiah; Isaiah's Power of Prediction, with its evidence on the character of Inspiration; and the question, Had Isaiah a Gospel for the Individual? A short index will guide the student to Isaiah's teaching on other important points of theology and life, such as holiness, forgiveness, monotheism, immortality, the Holy Spirit, etc.
Treating Isaiah's prophecies chronologically as I have done, I have followed a method which put me on the look-out for any traces of development that his doctrine might exhibit. I have recorded these as they occur, but it may be useful to collect them here. In chaps. ii.-iv. we have the struggle of the apprentice prophet's thoughts from the easy religious optimism of his generation, through unrelieved convictions of judgement for the whole people, to his final vision of the Divine salvation of a remnant. Again, chap. vii. following on chaps. ii.-vi. proves that Isaiah's belief in the Divine righteousness preceded, and was the parent of, his belief in the Divine sovereignty. Again, his successive pictures of the Messiah grow in contents, and become more spiritual. And again, he only gradually arrived at a clear view of the siege and deliverance of Jerusalem. One other fact of the same kind has impressed me since I wrote the exposition of chap. i. I have there stated that it is plain that Isaiah's conscience was perfect just because it consisted of two complementary parts: one of God the infinitely High, exalted in righteousness, far above the thoughts of His people, and the other of God the infinitely Near, concerned and jealous for all the practical details of their life. I ought to have added that Isaiah was more under the influence of the former in his earlier years, but that as he grew older and took a larger share in the politics of Judah it was the latter view of God, to which he most frequently gave expression. Signs of a development like these may be fairly used to correct or support the evidence which Assyriology affords for determining the chronological order of the chapters.