In
Roman Catholicism, a
dogmatic definition is an infallible statement published by a
pope or an
ecumenical council concerning a matter of faith or morals, the belief in which is required of all
Christians. Dogmatic definitions by popes are rare. Among them are the definition of
Pope Pius XII concerning the
Assumption of Mary in
1950 and the definition concerning Mary's
Immaculate Conception. [Which pope and which year?]