reason a Catholic cannot be tolerant of a theory which holds all religions to be equally useful; that is, equally useless. He cannot be tolerant of any theory which involves a denial of Catholic doctrine, since he acknowledges an infallible authority as the source of the Catholic doctrine which he holds. I am now and here neither asserting nor denying any theory or any doctrine, Catholic or non-Catholic. I am only setting forth the inconsistency implied in the toleration of principles opposed to one’s own, whatever those principles be. Is it then irreclaimable prejudice, or indifference to the obligation of principle, that makes some persons throw up their arms and raise a cry of horror when they hear that some Catholic has been excommunicated for having denied or questioned some Article of Catholic faith? What is taken as a matter of course and of common justice in every society and in every club in the country, namely that one who is false to his society and unfaithful to its rules deserves expulsion, is stigmatised as intolerance and moral tyranny in the Catholic Church. There are certain rules in every association which a member may not break under pain of expulsion. But a man may say what he likes, write what he likes, do as he likes; may deny every doctrine, despise every principle, and may nevertheless have, according to some, a right to remain a member of the Catholic Church out of which only Romish intolerance would drive him. Everyone then, whatever be his religious, philosophical, political, or social principles, must be intolerant of principles which are opposed to his own. Tolerance, however, claims a place in matters of opinion. But must not one think another’s opinions false if they are opposed to his own? Certainly; but, being only opinions, one has no right to claim a monopoly of certainty for one’s own as against those of others. Opinions have no claim to the privilege of principles. And what is true in theory of opinions holds in practice in matters of principle. One cannot, it is true, be tolerant of principles opposed to his own; but others must not suffer at his hands because they own principles which are not his. Everyone must have credit for honesty, since one cannot fathom the depths of another’s conscience. The Catholic Church, not to speak of its individual members, disowns such a pretension as that; _Ecclesia non judicat de internis_ is a maxim in Catholic theology. Thus, Catholic teaching, whilst it binds Catholics to be intolerant of principles and doctrines which it condemns, obliges them also to be tolerant of those who hold those principles and doctrines for the sake of the sincerity which it presumes in those who hold them. If we compare this tolerance, imposed as a duty by Catholic teaching, with the unlimited tolerance professed by some who assert the autonomy of individual reason, we shall find a contrast between, for instance, the noble tolerance of St. Francis de Sales and the bigotry of Voltaire.