Chris Lansdown is confused about Papal Infallibility and Ex Cathedra statements

He writes:

I have written a few posts on the topic of contraception (totaling about 4,000 words) and have been contemplating it for a while. The upshot is that I cannot accept any of the arguments against contraception which I have yet seen, and that if Humanae Vitae is an example of the pope speaking Ex Cathedra, then I can no longer keep an open mind about papal infallibility and must reject it as false. Thank you for your time.

Anyhow, if you care:

But if the Pope spoke Ex Cathedra on the issue, I don’t think that this discussion any longer has any relevance. No one but those who believe in papal infallibility reject contraception, and those who do can’t change their mind (especially since they don’t believe it by argumentation anyway).

Thanks for your time and I hope that my position on this does not preclude our discussing other matters where I our beliefs coincide more (while I was baptised Greek Orthodox, my beliefs are nearly catholic with the one big exception of papal infallibility).

I’m no expert in moral theology so don’t look to me for the fine points. However, FWIW, Humanae Vitae, while an expression of the ordinary magisterial teaching of the Church (i.e. what the Church has always taught and said and therefore infallible) was not an ex cathedra definition of dogma. It simply reiterated the constant teaching of the Church that nature is good and that our technologies are to assist, not thwart, natural processes. You can’t get an argument against papal infallibility out of your problems with Humanae Vitae since the Pope’s position is most emphatically not contrary to either Scripture or Tradition. Saying the arguments for the Tradition don’t appeal to your reason is not sufficient to rebut the infallible nature of the teaching. You would have to show that the teaching is absolutely contrary to Scripture and Tradition. It’s not.

Just to be clear, Papal infallibility is simply a corollary of the infallibility of the Church. It is reflected in Jesus’ promise to be with the Church to the end of the age and, in particular, in his promise that the Holy Spirit would lead the Church into all truth. An infallible definition is never new revelation. It is merely a clarified description of old revelation. (See this article for a discussion of that.) Thus, infallibility is a negative charism, not a positive act of inspired prophecy. In plain English, it’s the promise of the Holy Spirit that when the Church is guided to define its teaching formally, the Holy Spirit will not permit her to define error as doctrine.

Some Christians have a problem with this and see in this a denial of human freedom. Yet very few such Christians have any problem thinking that, as Paul said, “where the Spirit of the Lord is, there is freedom” or in thinking that the Scriptures (which recorded precisely what the Holy Spirit intended to be written) were not also written in complete freedom by the human authors. Same principle obtains here. Catholics would argue that the infallibility is not an expression of slavery, but of freedom. The Church is *liberated* to proclaim the truth in defining doctrine, set free (in that moment) from the bondage of ignorance, stupidity and sin to clearly articulate the revelation.

Papal infallibility is simply a corrollary of this. Other sources (see Catholic Answers, for instance), give the biblical, patristic and theological arguments for this better than me though. So I’ll let them do it. To see what I have to say about infallibility, go here.