Sedeprivationism

Sedeprivationism is a doctrinal position within Traditionalist Catholicism invented by the excommunicated theologian Michel-Louis Guérard des Lauriers which holds that the current occupant of the Holy See is a duly-elected pope, but lacks the authority and ability to teach or to govern unless he recants the changes brought by the Second Vatican Council. The doctrine asserts that since this council, occupants of the See of Peter are popes materialiter sed non formaliter, that is "materially but not formally". As such, sedeprivationists teach that all popes since Pope John XXIII have not 'attained the fullness of the papacy'.

Sedeprivationism is taught by a very small number of traditionalist Catholic groups such as the Istituto Mater Boni Consilii and Orthodox Roman Catholic Movement, among others.