But what need is there for searching for proofs? A single reflection banishes every difficulty. We have in the church two means for ascertaining whether a pontifical act is, or is not, a sovereign definition, an infallible decision. We have to enquire of the pontiff who is the author of it, or the people who subordinate themselves to his teaching. Neither one nor the other can deceive us in the answer they give. The divine promise continues equally assured in both: in the former, when he teaches; in the latter, when they listen and obey. It is what the theologians call active and passive infallibility. Admit that Pius IX. had left us in ignorance; that he published the Syllabus, but did not tell us what amount of assent he required of us. Well, none of us are in any doubt as to that. How many times has not this people said, how many times has it not repeated with an enthusiasm inspired by love, that this Syllabus, despised, insulted by the enemies of the church, they accept as the rule of their beliefs, as the very word of Peter, as the word of life come down from heaven to save us. Is it not thus that have spoken, one after the other, bishops, theologians, the learned and the ignorant, the mighty and the humble? Who amongst us has not heard this language? A celebrated doctor, Tanner, has said that in order to distinguish amongst the teachings of the church those which belong to its infallible authority, we must listen to the judgment of wise men, and above all consult the universal sentiment of Christians. If we adhere to this decision, it reveals to us our duties in regard to the sovereign act by which Pius IX. has withdrawn the world from the shadow in which it was losing its way, and has prepared for it a future of better destinies.