Editing Sedevacantism (section)

==== Relationship to sedeprivationism ====
In contrast to sedevacantists, [[sedeprivationism|sedeprivationists]] affirm the [[Thesis of Cassiciacum]] by the [[Order of Preachers|Dominican]] theologian Bishop [[Michel-Louis Guérard des Lauriers]] as being a valid position, which states that John XXIII and his successors are popes {{lang|la|materialiter sed non formaliter}} (“[[Hylomorphism|materially but not formally]]”), and that post-Vatican II popes will become legitimate once they recant their heresies.

This position is endorsed by the {{lang|la|[[Istituto Mater Boni Consilii]]}}.<ref>[[Istituto Mater Boni Consilii]] (IMBC). [https://www.sodalitiumpianum.com/who-we-are/ "Who we are"]. Retrieved 29 August 2021.</ref>