He took no interest in theology, and felt no sympathy for the Inquisition.[34] But he prudently left that institution alone to pursue its function of policing the ecclesiastical realm.

The Jesuits rendered him important assistance by propagating their doctrine of passive obedience to Rome.

Spain supported him with the massive strength of a nation Catholic to the core; and when the Spanish prelates gave him trouble, he could rely for aid upon the Spanish crown.

His own independence, as a prudent man of business, uninfluenced by bigoted prejudices or partialities for any sect, enabled him to manipulate all resources at his disposal for the main object of uniting Catholicism and securing Papal supremacy.

He was also fortunate in his family relations, having no occasion to complicate his policy by nepotism.