In a long course of years I have made many mistakes. I have nothing of that high perfection which belongs to the writings of saints, viz., that error cannot be found in them; but what I trust that I may claim all through what I have written, is this,—an honest intention, an absence of private ends, a temper of obedience, a willingness to be corrected, a dread of error, a desire to serve Holy Church, and, through Divine mercy, a fair measure of success. And, I rejoice to say, to one great mischief I have from the first opposed myself. For thirty, forty, fifty years I have resisted to the best of my powers the spirit of Liberalism in religion. Never did Holy Church need champions against it more sorely than now, when, alas! it is an error overspreading, as a snare, the whole earth; and on this great occasion, when it is natural for one who is in my place to look out upon the world, and upon Holy Church as in it, and upon her future, it will not, I hope, be considered out of place, if I renew the protest against it which I have made so often.
Liberalism in religion is the doctrine that there is no positive truth in religion, but that one creed is as good as another, and this is the teaching which is gaining substance and force daily. It is inconsistent with any recognition of any religion, as true. It teaches that all are to be tolerated, for all are matters of opinion. Revealed religion is not a truth, but a sentiment and a taste; not an objective fact, not miraculous; and it is the right of each individual to make it say just what strikes his fancy. Devotion is not necessarily founded on faith. Men may go to Protestant Churches and to Catholic, may get good from both and belong to neither. They may fraternise together in spiritual thoughts and feelings, without having any views at all of doctrines in common, or seeing the need of them. Since, then, religion is so personal a peculiarity and so private a possession, we must of necessity ignore it in the intercourse of man with man. If a man puts on a new religion every morning, what is that to you? It is as impertinent to think about a man’s religion as about his sources of income or his management of his family. Religion is in no sense the bond of society. – from the Bigiletto Speech (1879)