The hymn may be used to teach truth as well as to express emotion. If we are to accept Paul’s statements regarding the use of song in the churches in his early day, the didactic hymn is the oldest form of the Christian hymn. “Teaching and admonishing one another” is his phrase in Colossians 3:16. Indeed, we can go back to Moses for authority for it, for the ninetieth Psalm is largely didactic. In the Psalms we find more instruction than worship. There is really no reason why an assembly should not sing truth, as well as recite it, as it does in the Apostles’ or in the Nicene Creed. The didactic value of the hymn is too great that we should refuse its help in laying a foundation of doctrine in the hearts of the people of God. Never was it more necessary than now. It is significant of John Wesley’s appreciation of its didactic value that in his announcement of his hymnal of 1780, _The Large Hymn Book_, he refers to his grouping of the hymns under subjects, making the hymnal “a little body of experimental and practical divinity.” Many of our most frequently used hymns are unfeignedly didactic. Bishop Wordsworth’s “O day of rest and gladness” is a resume of the arguments for the validity of the Christian Sabbath. “The Church’s one foundation” is one of a series of hymns by Samuel J. Stone expounding the Apostles’ Creed. Heber’s hymn, “Holy, holy, holy, Lord God Almighty” is suffused with poetical feeling, but is none the less a didactic hymn emphasizing the doctrine of the Trinity. At the same time, this religious truth must have a poetic element. It is the great value of a hymn as a teaching method that it puts heart and feeling into the doctrine it expresses, and so gives it reality and appeal. Despite Dr. Austin Phelps’ rejection of Montgomery’s “Prayer is the soul’s sincere desire” as “without the wings of song,” the Church at large has been singing it for a century. Even if the last stanza were omitted, it would still be a good hymn, because the doctrine of prayer is clothed in such beautiful and inspiring language that it is eminently fitted for the expression of a congregation in song. _The Doctrinal Hymn._ The doctrinal hymn is simply a limited form of the didactic hymn in that it is devoted to the promulgation of the leading Christian doctrines, while the general didactic hymn may be used to inculcate any truth or duty, whether of a fundamental character or not. The use of the hymn to teach the doctrines of the Church has numerous advantages. It is clear and succinct, not obscuring the truth with philosophical or metaphysical subtleties. It is dogmatic and not argumentative. It has the mnemonic advantage of rhythm and rhyme and is easily remembered. It has the inspiration of collective singing. Above all it is vivid and poetical, emotionalizing and vitalizing what in the philosopher’s hands becomes abstract and dry.