Description: The enduring influence of the Catholic Church has many sources—its spiritual and intellectual appeal, missionary achievements, wealth, diplomatic effectiveness, and stable hierarchy. But in the first half of the nineteenth century, the foundations upon which the church had rested for centuries were shaken. In the eyes of many thoughtful people, liberalism in the guise of liberty, equality, and fraternity was the quintessence of the evils that shook those foundations. At the Vatican Council of 1869–1870, the church made a dramatic effort to set things right by defining the doctrine of papal infallibility.