The Independent sacramental movement refers to a loose collection of individuals and Christian denominations who are not part of the historic sacramental Christian denominations and yet continue to practice the historic sacramental rites independently. Many such groups originated from schisms of these larger denominations, and they claim to have preserved the historical episcopate or apostolic succession, though such claims are frequently disputed or rejected outright by the historic churches of Rome, Constantinople, the Union of Utrecht, and Canterbury. Groups cited by ISM adherents as being part of the movement may struggle to demonstrate a historical connection to other denominations apart from a claim to apostolic succession. In addition, some groups which do not claim apostolic succession may sometimes have been claimed by ISM sources as part of their movement. Groups within the Independent sacramental movement frequently share the following characteristics:
The term was popularized in 2005 by John Plummer, in The Many Paths of the Independent Sacramental Movement, although it was used earlier, in 2002 by Richard Smoley, in Inner Christianity, and perhaps first used in the mid-1970s by a short-lived cooperative organization called the Synod of Independent Sacramental Churches. Independent sacramental groups range from the broadly inclusive to the socially conservative; also from the traditionally orthodox to the esoteric, although the term is most commonly employed to refer to the liberal end of the spectrum. While the term "Independent sacramental" originated as an eticdescription, it has been used increasingly as an emic self-description by members of some of these organizations. Independent Orthodox, Catholic, and Anglican Movement The term is actually an expansion of an earlier term: the Independent Orthodox, Catholic, and Anglican Movement. This earlier term was used extensively during many years when many of these groups cooperated, although they were not in formal communion with one another. The majority of these groups' holy orders and sequences of apostolic succession are derived through mutually common sources, especially Arnold Harris Mathew, Aftimios Ofiesh, Carlos Duarte Costa, and Joseph René Vilatte. Independent Sacramental or Independent Catholic movement It remains difficult to define the ISM as an entity and to distinguish it from the closely related Independent Catholic movement; the two terms can sometimes be used interchangeably, to refer to the same groups.
