Malleus Haereticorum - St. Anthony of Padua
The great Anthony of Padua has a universal appeal in the Catholic Church (he is truly a "catholic" saint). His statue can be found in churches the world over. He is most famous as the patron of lost articles. God knows how many times I've invoked his intercession in that area. But he has earned another title for his gift of converting the "sheep who had wandered" with his preaching - malleus haereticorum - or "the hammer of heretics."
While he is known for being a saint of the Italian city of Padua, St. Anthony was actually from Portugal, and spent much of his priestly ministry traveling across France and Italy, offering Masses and preaching. He was literally a one-man crusade against the prevailing heresy in those countries at the time, which was Catharism (also known as Albigensianism). He was so effective in converting people back to the Church that in response, the Cathars of the town of Rimini tried to poison him. Though he knew their treachery, he nevertheless ate at the feast they had prepared for him, and was unharmed.
St. Anthony continued to preach in Rimini, but some of the Cathars still did not heed his words. He demonstrated their hardness of heart when he preached on the shore of a river there, and in response, fish in the water sticked their heads out and turned to attentively hear his words. At this miraculous sight, people fell at the saint's feet and listened. Many returned to the Church.
Due to this reputation, Dom Gueranger invoked St. Anthony's intercession in the struggle against the heresies of modern times, which often have many similiarites to the heresy of Catharism. He wrote, "O thou who dost daily fly to the aid of thy devoted clients in their private necessities, thou whose power is the same in heaven as heretofore upon earth, succour the Church, aid God's people have pity upon society, now more universally and deeply menaced than ever. O thou ark of the covenant, bring back our generation, so terribly devoid of love and faith, to the serious study of sacred letters, wherein is so energizing a power. O thou hammer of heretics, strike once more such blows as will make hell tremble and the heavenly powers thrill with joy" (The Liturgical Year, Vol. XII, June 13).
St. Anthony of Padua, Hammer of Heretics, pray for us!