The whole difficulty seems to arise from the long prevalent assumption that chaps. xl.-lxvi. form a whole in themselves. Natural as the feeling against disintegration may be, the difficulties in the way of admitting the unity of chaps. xl.-lxvi. are insurmountable. Even if, by a bold assumption, we grant the unity of authorship, it is plain upon the face of it that the chapters in question cannot have been composed at the same time or under the same circumstances; literary and artistic unity is wholly wanting. But once admit (as it is only reasonable to do) the extension of Jewish editorial activity to the prophetic books and all becomes clear. The record before us gives no information as to its origin. It is without a heading, and by its abrupt transitions, and honestly preserved variations of style, invites us to such a theory as we are now indicating. It is only the inveterate habit of reading Isa. xlix.-lxvi. as a part of a work relating to the close of the Exile that prevents us from seeing how inconsistent are the tone and details with this presupposition.
The present article in its original form introduced here a survey of the portions of Isa. xl.-lxvi. which were plainly of Palestinian origin. It is needless to reproduce this here, because the information is now readily accessible elsewhere; in 1881 there was an originality in this survey, which gave promise of a still more radical treatment such as that of Bernhard Duhm, a fascinating commentary published in 1892. See also Cheyne, _Jewish Quarterly Review_, July and October 1891; _Introd. to Book of Isaiah_ (1895), which also point forward, like Stade's _Geschichte_ in Germany, to a bolder criticism of Isaiah.
IV. _Non-Isaianic Elements in Chaps. i.-xxxix._--We have said nothing hitherto, except by way of allusion, of the disputed prophecies scattered up and down the first half of the book of Isaiah. There is only one of these prophecies which may, with any degree of apparent plausibility, be referred to the age of Isaiah, and that is chaps. xxiv.-xxvii. The grounds are (1) that according to xxv. 6 the author dwells on Mount Zion; (2) that Moab is referred to as an enemy (xxv. 10); and (3) that at the close of the prophecy, Assyria and Egypt are apparently mentioned as the principal foes of Israel (xxvii. 12, 13). A careful and thorough exegesis will show the hollowness of this justification. The tone and spirit of the prophecy as a whole point to the same late apocalyptic period to which chap. xxxiv. and the book of Joel; and also the last chapter (especially) of the book of Zechariah, may unhesitatingly be referred.