Here is an intriguing remark from Blessed John Henry Cardinal Newman’s work An Essay in aid of a Grammar of Assent:
[I]f it is the duty of the Church to act as “the pillar and ground of the Truth,” she is manifestly obliged from time to time, and to the end of time, to denounce opinions incompatible with that truth, whenever able and subtle minds in her communion venture to publish such opinions. (p. 149; emphasis added)
Surely if the Christian church is in fact the pillar and ground of the truth as St. Paul says, then it seems clear that a bare minimum of responsibility she bears is represented by what Newman says in the quotation. How can she be a pillar of the truth if she remains silent in the face of heresy? With Newman’s question in view this duty of the Church becomes a defense of the notions that she is also Catholic and Apostolic.
I think Newman shines a rather embarrassing light upon Protestantism here as well. How can Baptists, Methodists, Presbyterians, Lutherans, Plymouth Brethren, Pentecostals, and who knows whom else be pillars of the truth when they do not even agree with each other? Christ is not divided, nor is the truth. The very fact that these communities disagree with each other undermines, it seems to me, their respective claims concerning the truth, and their position is made worse with respect to their standing as pillars of truth when they all deny their own infallibility: they are reduced to remarkably unstable “pillars” if they are more sure of their own fallibility than they are of the truth.
Newman’s words help us to see that we need the Church to stand as a pillar of truth, and that in order to so stand she must be infallible as well.