It has been already laid down that sacred song is the union of music to the words of inspired truth, with the view of its thus becoming an auxiliary in the work of Christian instruction and sanctification.
Before passing on to the approaching details let us stop for a moment fairly to consider the result of this principle as it affects the comparison generally.
Here, on the one hand, we have the Canto Fermo, with its vast variety of music, embracing an equally varied range in the stores of divine revelation, inasmuch as it is the counterpart in song of the entire Ritual; on the other hand we have the works of modern music, of which I am speaking, embracing scarcely more than a fraction of the Ritual. With a vast numerical rather than a real variety in point of the one constitutive element of sacred song—viz., music—they are poverty itself as regards the other—viz., inspired truth—the Kyrie, Gloria, Credo, Sanctus, and Agnus Dei, from the Ordinary of the Mass, and a small number of hymns, antiphons, and scattered verses from the Holy Scriptures, in the form of motets, being literally the sum-total of their possession in this element.
And now to carry the comparison into its details. The divine idea of sacred song could not have been known to us without a revelation, the very gift itself being, from its nature, the companion of a revelation. We are not, therefore, as has been remarked in the introduction, thrown upon our own natural powers of speculation either for our general knowledge of the divine idea itself or for gaining an insight into its constituent details; indeed, without revelation this would have been altogether beyond our natural capacities. But since God became man and founded his own society, the Catholic Church, and both taught himself and placed inspired teachers in it to succeed him, the ideas of God as to questions that concern the welfare of his church have, through the Incarnation of the Son, been brought to the level of our capacities, and are to be found in the Scripture and in Christian theology, and are there to be sought for as occasion may require. Thus examined, then, by the light of the Christian revelation, the divine idea of sacred song will, without urging that these are co-extensive with it, admit of being resolved into the ensuing points; the truth of which will be proved separately, as they come forward successively in the course of the comparison. They are as follows:
I. Authority: 1, ecclesiastical; 2, moral.
II. Claim to the completeness and order of a system.
III. Moral fitness: 1, as a sacrificial song; 2, as a song for the offices of the church.
IV. Fitness for passing among the people as a congregational song.
V. Moral influence in the formation of character.
VI. The medium or vehicle for divine truth passing among the people.