Ingravescentibus Malis §2

² However, anyone who studies with diligence the records of the Catholic Church will easily recognize that the true patronage of the Virgin Mother of God is linked with all the annals of the Christian name. When, in fact, errors everywhere diffused were bent upon rending the seamless robe of the Church and upon throwing the Catholic world into confusion, our fathers turned with confident soul to her "alone who destroys all heresies in the world" ( Roman Breviary ), and the victory won through her brought the return of tranquillity.