Ex cathedra
Ex cathedra is from Latin, meaning "from the chair" (of the authorized and authoritative teacher).
In Catholicism the phrase refers to dogmatic teachings issued from the Chair of Peter, that is, from the successor of Saint Peter, the pope. These teachings must meet certain specific criteria. Teachings defined as ex cathedra are specifically limited solely to papal teachings promulgated by the Holy Father when as shepherd of the whole Catholic Church and successor of Peter he officially teaches in his capacity as universal shepherd of the whole orthodox catholic Christian Church and Vicar of Christ a doctrine on a matter of faith or morals and addresses it to the entire world. These universal teachings are defined by the Catholic Church as binding and infallible doctrines. According to the Magisterium of the Catholic Church, those Catholics who do not subscribe to these dogmas are guilty of mortal sin.