Jason now begins his [church] infallibility / canon of the Bible disanalogy. He claims that there was more consensus on the latter than the former. In fact, development proceeded in both cases, rapidly in the fourth century. Most of the explicit elements of the historic papacy were in place by the reign of Pope St. Leo the Great (440-461), which was not long after the formulation of the canon. The true late (and radical) development here was when Protestants decided to demote the Deuterocanon over a thousand years later.
As I mentioned in an earlier response to Dave, we have to distinguish between developments that are implied by apostolic teaching and developments that aren't. The amount of time it took a concept to first appear in the extant historical record or to reach a particular level of popularity isn't as important as whether the concept is an implication of what the apostles taught.
I've used a DNA illustration in the past. Jesus' humanity implies that He had DNA, so we conclude that He had it, even though we didn't develop an awareness of DNA until recently. If somebody had claimed, in the same year that DNA was discovered, that Jesus was six feet tell, would we place the two conclusions in the same category? Would we say that the two concepts developed in the same manner? No, since DNA is a probable implication of a person's humanity, whereas a height of six feet isn't an implication, but only a possibility. A human might be that tall, but we wouldn't conclude that he's six feet tall merely because he's a human.
As I've argued in previous responses to Dave and elsewhere, nothing the apostles taught implies a papacy, much less the entire Roman Catholic system of church infallibility. Thus, even if the twenty-seven-book New Testament first appeared in the extant historical record around the same time as the papacy, or even if the two attained a high level of popularity around the same time, we would still have to distinguish between the two. The canon is an implication of apostolic teaching. The papacy isn't.
In my first response to Dave, I replied to his comments about the Old Testament canon. I explained why he was wrong about the relevance of that canon to the context I was addressing. I also linked to an article in which I summarize an Evangelical argument for that canon. The Jewish consensus we appeal to predates the Christian consensus Dave appeals to.
If Dave is going to reduce church infallibility to "most of the explicit elements of the historic papacy", then the appropriate object of comparison would be some reduced form of the New Testament canon. To compare "most of the explicit elements of the historic papacy" to the entirety of the twenty-seven-book New Testament is misleading. The Catholic system of church infallibility involves more than a papacy.
And as I explained in an earlier response to Dave, forming a canon of scripture, which involves judging many documents written by many authors to different locations under different circumstances, is much more difficult than judging whether one individual has papal authority. We would expect a canon of scripture to take some time to develop, as we see with other canons of literature. But why would so much time be needed to discern that one bishop has universal jurisdiction? The idea that we should expect the two concepts to be discerned in a similar manner is unreasonable.
And what claims do Catholics make about the history of the papacy? Have they usually suggested that the doctrine was discerned in a way similar to how the canon was gradually discerned? Were forgeries like the Pseudo-Isidorian Decretals intended to promote such a view of the papacy's development? Is that the impression you come away with after reading the First Vatican Council? Or after reading a Catholic apologist who writes about how necessary the papacy is for church unity? (How was unity maintained before an understanding of the papacy developed?) Or after seeing a Catholic argue that Peter acted as a spokesman for the disciples in the gospels because of his papal authority? Or that Peter was presiding as a Pope in Acts 15? Or that Victor acted as a Pope, exercising universal jurisdiction, during the Quartodeciman controversy? Etc. It seems that Catholics often try to have it both ways. On the one hand, they suggest that a papacy involving universal jurisdiction was understood in the earliest generations of church history. On the other hand, they appeal to doctrinal development when evidence is offered against an early understanding of the papacy and they're unaware of a way to overcome that evidence.
The twenty-seven-book New Testament canon and the papacy are similar in some ways. Both concepts seem to first appear in the extant historical record around the middle of the third century. But the reasoning offered to justify each is much different, as is their history following their first appearance in the historical record.
The canon is first found in Origen, whose qualifications for judging such a matter are significant. See here. The papacy is first found in the Roman bishop Stephen, a man about whom we have much less information, when he was acting in his own interests in a dispute with other Christians. As I documented in a previous response to Dave, Stephen's claim was denounced by bishops in the West and East. Though disputes over the canon continued after Origen's day, his twenty-seven-book canon wasn't nearly as controversial as Stephen's assertion of papal authority, and Origen's canon would go on to gain far more widespread acceptance over time. Stephen's church would accept Origen's canon, but the churches of the East would long reject Stephen's papal claims, as reflected to this day in Eastern Orthodoxy.