We wish here to call the particular attention of the reader to a fact which is too often lost sight of in treating of the customs of the early Church. We refer to the Disciplina Arcani, as it was called, or the Discipline of the Secret, in virtue of which the principal mysteries of our holy faith and the nature of many of the public prayers of the Church were carefully concealed from all who were not considered as belonging to the household of faith, and this with a view to follow out to the letter that sacred admonition of our Divine Lord himself, viz. : not to “cast pearls before swine or give what was holy to dogs.” “The mysteries,” says St. Athanasius, “ought not to be publicly exhibited to the uninitiated, lest the Gentiles, who understand them not, scoff at them, and the catechumens, becoming curious, be scandalized” (Apol. contra Arimi., p. 105).
The caution which was to be observed during the prevalence of this discipline—which, as we have said in another place, lasted during the first five centuries—influenced the preachers of those days very considerably, from the fact that their audiences were often made up of Jews, Gentiles, pagans, and others who were wholly ignorant of the nature of our belief, and who would, had they but understood it in all its bearings, have made it a pretext for inciting fresh persecution.