Having written recently on the meaning of the Psalms by observing its structure, I wanted to clarify how some people view the Psalter’s structure. Here is a basic summary of the issue. It’s definitely some food for thought.
The traditional view divvies up the Psalter into five equal portions:
I. Book 1 (1–41)
II. Book 2 (42–72)
III. Book 3 (73–89)
IV. Book 4 (90–106)
V. Book 5 (107–150)
These five books within the Psalter have various characteristics and emphases but nothing they are simply divisions that the editor(s) put together when creating the Psalter. Nothing is wrong with this view, and, in fact it quite obviously pulls the division from the text itself and from tradition.
Another proposal seeks to define the relationship between the five books of the Psalter in cogent and theological powerful way. Gerald Wilson observed this trajectory in the Psalter first in his publication, The Editing of the Hebrew Psalter (1985). However, he had hinted at this cohesion to the Psalms previously and provided clarifying insights afterwards. John Walton began to popularize this view through writing in JETS. Later, he even supported this this proposal in his introduction to the Old Testament. Today, no discussion of the Psalms is replete without discussion of Wilson’s proposal for its structure. I call this view the “intentional structure” view of the Psalter.
INTENTIONAL STRUCTURE OF THE PSALTER
Gerald Wilson proposes “purposeful editorial activity” in the Psalter, which he observed by three method of the editor used to group the Psalms. First, the editor grouped the psalms by the author designation derived from the psalm headings. While this may not the primary way the editor grouped the psalms, it is interesting to note that book I opens with David (Psalm 3; more on why Psalm 3 later), book II abruptly changes authorship to the sons of Korah, Book III opens with Asaph’s collection, and book IV opens with a psalm by Moses. While this may not be the only organizing principle, “author-changes do serve, however, to mark strong disjunctions within the first three Books.” Thus, the function of author changes in the Psalms is to mark strong disjunctions between what has come before and what will follow.
Wilson writes concerning these structure markers, “This correspondence of authorship-change with the book divisions and the doxologies which serve to mark them is hardly fortuitous. It must represent conscious editorial activity either to introduce such author-changes in order to indicate disjuncture between such divisions or to make use of such existing points of disjuncture in the division of the Psalter.” In this way, an intentional structuring of the Psalms is observed.
Since Books IV and V do not end with this abrupt author change, other strategies must exist to cohere them together. Admitting this difficulty, Wilson offers his explanation as to why the change in authorship as seams between books ends. He writes, “This may be due to the paucity of non-Davidic authors in Ps. xc-cl. Apart from the Mosaic Ps. xc which opens Book IV, the only non-Davidic author mentioned is Solomon for Ps. cxxvii, which is a fixed part of the hm’lwt collection. For obvious reasons, author-change can no longer serve as an effective indicator of disjuncture.”
The second intentional organizing principle Wilson observes is genre groupings. Thus, throughout the psalter different genres can be observed through the descriptions of the psalm in the title headings. Unlike the function disjunctive function of author change, the function of genre group is to bind together and soften the disjuncture between groupings within the Books of the Psalms.
Quoting Wilson’s summary in full clarifies the function and meaning of genre groupings in the Psalms:
In summary, while the analysis of the distribution of genre terms in the psalms-headings reveals the existence of clusters of terms scattered throughout the Psalter, there is no evidence of any consistent attempt to group all psalms by genre categories (as in Mesopotamian catalogues). There is evidence, however, of the editorial use of these genre terms and clusters to assist in the organization of the Psalter. Basic divisions of the psalms are indicated by the disjuncture (in the Psalms-headings) of author attributions and genre designations. Such disjuncture is most noticeable as the “seams” of the Psalter: at the book divisions.
In contrast to this “divisive” function of the Psalms-headings, genre terms are used within these larger segments to bind together and to “soften” the transition between groups of psalms. The widespread and consistent nature of this phenomenon militates against any chance distribution of the psalms and supports the idea of purposeful, editorial activity behind the organizational process.
The third organizational technique differs from the first two methods and is used specially in Books IV and V (where the first two methods of conspicuously absent). The editor used Halleluiah’s in the superscripts and post scripts throughout Books IV and V. These Halleluiah psalms end Book IV, begin book V and ends Book V. An additional factor is that immediately after these Halleluiah psalms, this phrase beings the next psalm: “Praise YHWH for he is good, for his mercy is for ever.” Wilson thinks this phrase serves to “introduce the segments which follow.”
Wilson’s conclusion of the third organizing principle is that “All these factors confirm that the conjunction of hllwyh and hwdw psalms in these texts is not coincidental, but is the result of conscious arrangement according to accepted traditions and serves to mark “seams” of the Psalter as a whole.”
Thus, Wilson cogently explains that three editorial techniques for grouping the five Books exists. The editor(s) used author-changes, genre groupings, and key phrases (Halleluiah, etc.) to indicate transitions and cohesion between the five Books.
While the significance of all this seems minimal, it has huge theological important when one considers the content of each book. While this is neither the time nor the place to write it, one could demonstrate from the Psalter a chronological-redemptive progression from David’s reign to Judah’s exile that both points back to the Davidic covenant and looks forward to an ideal Davidic King (the Messiah).
 Gerald H. Wilson, “Evidence of editorial division in the Hebrew Psalter,” Vetus testamentum 34, no. 3 (1984): 336–352.
 Gerald H. Wilson, “The use of royal psalms at the ‘seams’ of the Hebrew Psalter,” Journal for the Study of the Old Testament 35 (1986): 85–94.
 John H. Walton, “Psalms: A Cantata About the Davidic Covenant,” Journal of the Evangelical Theological Society 34, no. 1 (March 1991): 21–31.
 Andrew E. Hill and John H. Walton, A Survey of the Old Testament, Third ed. (Grand Rapids: Zondervan, 2009).
 Wilson, “Evidence of editorial division in the Hebrew Psalter,” 337.
 For a defense on the originality of the psalm headings, see Bruce Waltke, “Superscripts, Postscripts, or Both,” Journal of Biblical Literature 110, no. 4 (Winter 1991): 583–596.
 Wilson, “Evidence of editorial division in the Hebrew Psalter,” 339.
 Ibid., 339–340.
 Ibid., 345.
 Ibid., 349.
 Ibid., 352.