The main grounds on which the Davidic authorship of this psalm is denied are four. First, it is alleged that its conceptions of sin and penitence are in advance of his stage of religious development; or, as Cheyne puts it, "David could not have had these ideas" ("Aids to Dev. Study of Crit.," 166). The impossibility depends on a theory which is not yet so established as to be confidently used to settle questions of date. Again, the psalmist's wail, "Against Thee only have I sinned," is said to be conclusive proof that the wrong done to Bathsheba and the murder of Uriah cannot be referred to. But is not _God_ the correlative of _sin_, and may not the same act be qualified in one aspect as a crime and in another as a sin, bearing in the latter character exclusive relation to God? The prayer in ver. 18 is the ground of a third objection to the Davidic authorship. Certainly it is hopeless to attempt to explain. "Build the walls of Jerusalem" as David's prayer. But the opinion held by both advocates and opponents of David's authorship, that vv. 18, 19, are a later liturgical addition, removes this difficulty. Another ground on which the psalm is brought down to a late date is the resemblances in it to Isa. xl.-lxvi., which are taken to be echoes of the prophetic words. The resemblances are undoubted; the assumption that the psalmist is the copyist is not. The personified nation is supposed by most modern authorities to be the speaker; and the date is sometimes taken to be the Restoration period, before the rebuilding of the walls by Nehemiah (Cheyne, "Orig. of Psalt.," 162); by others, the time of the Babylonish exile; and, as usual, by some, the Maccabean epoch. It puts a considerable strain upon the theory of personification to believe that these confessions of personal sin, and longing cries for a clean heart, which so many generations have felt to fit their most secret experiences, were not the wailings of a soul which had learned the burden of individuality, by consciousness of sin, and by realisation of the awful solitude of its relation to God. There are also expressions in the psalm which seem to clog the supposition that the speaker is the nation with great difficulties--_e.g._, the reference to birth in ver. 5, the prayer for inward truth in ver. 6, and for a clean heart in ver. 10. Baethgen acknowledges that the two latter only receive their full meaning when applied to an individual. He quotes Olshausen, a defender of the national reference, who really admits the force of the objection to it, raised on the ground of these expressions, while he seeks to parry it by saying that "it is not unnatural that the poet, speaking in the singular, should, although he writes for the congregation, bring in occasional expressions here and there which do not fit the community so well as they do each individual in it." The acknowledgment is valuable; the attempt to turn its edge may be left to the reader's judgment.