Ad Petri Cathedram §116

¹¹⁶ This is a serious matter that has occasioned much sorrow and unhappiness and induces Our predecessors to summon the laity to the ranks of a peaceful militia, Catholic Action. It was their wise intention that the laity should cooperate in the apostolate of the hierarchy. In this way, what the hierarchy could not do under present circumstances, these Catholic men and women would accomplish in a spirit of generosity. They would work, of course, in union with their bishops and in constant obedience to them.