The question has been raised as to just what the divines might have meant by the noun “psalms” in the Westminster Confession of Faith (1648).1 WCF 21.5 says,
5. The reading of the Scriptures with godly fear, the sound preaching and conscionable hearing of the Word, in obedience unto God, with understanding, faith, and reverence, singing of psalms with grace in the heart; as also, the due administration and worthy receiving of the sacraments instituted by Christ, are all parts of the ordinary religious worship of God: beside religious oaths, vows, solemn fastings, and thanksgivings upon special occasions, which are, in their several times and seasons, to be used in an holy and religious manner.
It has been suggested that psalms here might include something other than the 150 canonical psalms, that it might include extra canonical songs. This is an interesting question worthy of investigation and a an interesting exercise in confessional hermeneutics. How should we seek to interpret our confessional documents?
As we interpret all other documents, Scripture included, we begin by trying to ascertain what the word psalm meant in context. The most obvious sense would seem to be a reference to the 150 canonical psalms in Holy Scripture. The church had sung the Psalms since the earliest post-apostolic days. Though the psalms are not often sung today and in some cases they are not easy to find in some song books, prior to the second half of the 20th century the psalms were widely sung. The patristic church sang the psalms. The medieval church sang the psalms, even if that singing was largely sequestered to monks and monastic choirs, and the Reformers sang the 150 canonical psalms.
Is there any evidence that Reformed writers prior to the Westminster Assembly used the word psalm in the broader sense? If we judge by his use of the word “psalm” in his 1557 commentary on the Book of Psalms, Calvin used the word to refer to canonical psalms. The “psalmist” is a person who composed a canonical psalm. In his treatises, including his 1559 Institutes, where the word psalm occurs about 500 times, the word psalm seems to refer almost invariably to a canonical psalm. In his commentary on 1 Corinthians 14:26 he did not comment on the Latin noun canticum (the Greek NT has ψαλμὸν). The closest thing we get to a definition is found in his 1548 commentary on Colossians 3:16:
…that a psalm is that, in the singing of which some musical instrument besides the tongue is made use of: a hymn is properly a song of praise, whether it be sung simply with the voice or otherwise; while an ode contains not merely praises, but exhortations and other matters. He would have the songs of Christians, however, to be spiritual, not made up of frivolities and worthless trifles. For this has a connection with his argument.
These characterizations leave some questions unanswered but we can fill in some of the blanks for Calvin’s own practice. We know that he translated some of the Psalms for singing and adopted the French Psalter of Clement Marot (1496–1544) for use in public worship in Geneva. In the Genevan liturgy the congregation sang nothing in public worship except Scripture (mostly Psalms) and the Apostles’ Creed as a summary of the Word.
Ursinus’ use of the word psalm, in his 1585 Corpus Doctrinae (his commentary on the Heidelberg Catechism), referred to the canonical songs. I suspect that an investigation William Ames (1576–1633) 1627 Marrow of Divinity and in his (untranslated) 1628 Bellarminus Enervatus (1629) used psalm only to refer to canonical psalms. These writers and texts are typical of that which influenced the Westminster Divines. Certainly they were well read in Calvin, Ursinus, and Ames. It is possible that, in early orthodox usage, leading up to the Westminster Assembly, psalm might have been used to include non-canonical songs but that usage does not seem to be prominent.<sup>2</sup>
There is a document proximate to the Westminster Confession that might help us understand what the divines meant by psalm in WCF 21.5. Particularly, we should look at the Westminster Directory of Publick Worship (1644). The last chapter of the Directory was titled, “Of Singing Of Psalms.” Under that heading the divines declared:
It is the duty of Christians to praise God publickly, by singing of psalms together in the congregation, and also privately in the family.
In singing of psalms, the voice is to be tunably and gravely ordered; but the chief care must be to sing with understanding, and with grace in the heart, making melody unto the Lord.
That the whole congregation may join herein, every one that can read is to have a psalm book; and all others, not disabled by age or otherwise, are to be exhorted to learn to read. But for the present, where many in the congregation cannot read, it is convenient that the minister, or some other fit person appointed by him and the other ruling officers, do read the psalm, line by line, before the singing thereof.
When we consider that, as Chad van Dixhoorn’s recent commentary reminds us, the divines worked diligently to compose a Psalter that contained only the 150 canonical songs.
It may be that the word psalm was used in the 16th and 17th centuries to refer to non-canonical songs. It is true that there were synonyms for the canonical psalms (e.g., canticum, hymnus, ode, oratio) but the preponderance of evidence leads us to think that we should interpret the word psalm in WCF 21.5 to refer to a canonical psalm.
1. The edition linked here is that adopted by the Orthodox Presbyterian Church.
2. I searched about 114 orthodox Reformed texts (from Junius, Perkins, Bucanus, Cartwright, Twisse, Gilespie, Diodati, Paraeus) from 1600 to 1640 and found no obvious evidence of psalm used to include an extra-canonical song.