The term is from Latin for the “discipline of secrecy.” It concerns the secrecy practiced by the early church so that certain teachings and practices were not shared with converts until they were initiated and had begun full participation in the life of the Christian community. Catechumens in the early church were dismissed from the Sunday service before the prayers of the faithful, the peace, and eucharistic sharing. Some have noted parallels of the Disciplina Arcani to the secrecy of mystery religions. But the main reasons for the Disciplina Arcani were to protect the church during times of active persecution or marginal toleration, and a catechetical approach that emphasized experiencing the initiatory sacraments (including baptism, anointing, laying on of hands, and first communion) before learning about them. After the sixth century the need for secrecy had passed, but there was continuing catechetical emphasis on experience and participation. The BOS explains that “The catechetical methodology of the catechumenal and baptismal rites is: experience first, then reflect.” See Mystagogy.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from “An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians,” Don S. Armentrout and Robert Boak Slocum, editors.