Secret Discipline (Lat. arcani disciplina), a term used to signify a practice of the early Christian Church of performing the rites of religion with secrecy. It was founded upon the words of Christ, "Give not that which is holy unto the dogs," etc. (Mt 7:6), and began to be common shortly after the middle of the 2d century. The first reason for its adoption was to guard the more sacred and mysterious doctrines from popular misconception and blasphemy among the pagans. The discipline of the secret appears in several forms:
(1.) Both unbelievers and catechumens were dismissed from the church, when the ordinary service was closed, by one of the deacons, who said, "Ire, missa est" — " Go, the assembly is dismissed." After this the sacrament was administered.
(2.) The lectures addressed by the presiding teacher to the body of catechumens in general were confined to the general doctrines of Christianity. The more mysterious doctrines, those which regarded the sacraments of baptism and the eucharist, called "Mystagogie," were only communicated at the close, and to those only who had undergone the preliminary probation.
(3.) The eucharist, if referred to at all in the presence of the uninitiated, was spoken of in words so conceived as to conceal its nature. Some very curious examples of this concealment might be cited — e, g. Epiphanius, referring to the formula "this is my. body," writes, "This is my that thing" (Τοῦτό μου ἐστι τόδε). The mysteries thus specially guarded were baptism, the unction, or chrism ordination of priests, the Lord's supper, liturgy, the knowledge of the Holy Trinity, the Creed, and the Lord's Prayer. See Coleman, Christ. Antiq. p. 85. SEE ARCANI DISCIPLINIA.