Having written this post, I'm not sure I agree with my own argument. I'm going to go ahead and post it, but I think the issue of logical necessity of Church infallibility is a much closer call than I had initially assumed it to be. Initially, I thought it unneccesary but helpful; upon re-examination, it may, in fact, be neccesary. Anyways, I invite you to read this over and let me know what you think, because I'm still sort of stewing it over in my brain:
I like Peter Kreeft. A lot. A whole lot. But one of his arguments in Fundamentals of the Faith on sola Scriptura is, in my opinion, bad. Here's the argument:
Third, sola scriptura violates the principle of causality: that an effect cannot be greater than its cause. The Church (the apostles) wrote Scripture, and the successors of the apostles, the bishops of the Church, decided on the canon, the list of books to be declared scriptural and infallible. If Scripture is infallible, then its cause, the Church, must also be infallible.
Now I happen to agree with him that sola Scriptura is incorrect, and I also think that the role of the Magisterium and Tradition in setting the canon is a really good proof of the need for a living infallible Church in a post-apostolic age. Having an infallible Church ensures that we have an "infallible collection of infallible books," instead of what R.C. Sproul calls the Protestant Bible: a "fallible collection of infallible books."
But the argument from causality here is totally wrong, in my opinion. I think if we're going to present a comprehensive, Biblical, logical case why sola Scriptura is untenable, we need to prune the bad arguments, so they don't get in the way. This is on bad argument, in my opinion. First and foremost, the Apostles, the agents of Scripture-writing, were fallible, even after Pentecost: Galatians 2:11 stands for nothing if not that. So it's not logically required (even if it helps) for the writers or compilers of Scripture to be infallible or inspired. And an either/or situation would work fine: an inerrant compiler of Scripture would be able to choose the inspired works from the uninspired; likewise, it wouldn't take inspiration for a layperson or a church to realize that an inspired author's works are inspired. Additionally, a fallible and uninspired person could assemble an inerrant list (which is what Sproul claims that Protestants have done): logically, it's unlikely (and how would you know they're inspired?), but it's possible, which is what Kreeft seems to deny.
I'm sure Kreeft would respond to this, perhaps arguing something like:
- The Apostles were infallible when acting in their official capacity. After all, if one of the Apostles happened to be wrong on some doctrinal issue, it would destroy the Church: could you imagine how bad it would be if, say, James started teaching something different from Peter? The flock would be dispersed instantly. Obviously, not everything they wrote was infallible: they could forget the eggs on the grocery list, etc. But everything within the scope of their Apostleship was: why should speaking be any different? Personal falliblity, official infallibility.
- If their written preaching is infallible, why not their spoken word? Particularly when many of the Scriptures were dictated: see Romans 16:22 for a hello from Tertius (Paul's scribe). Additionally, Acts is a history: if the things said by the Apostles weren't inspired, then they're still not inspired written down (quotes in Scripture aren't automatically inspired by virtue of being in Scripture: Psalm 14:1, for example, quotes an uninspired fool).
- Alternatively, if the Apostles could be wrong on issues of faith and morals, the only way to know what is and what is not inspired is to have an infallible Church. Otherwise, it defeats the point of infalliblity and divine inspiration. If some statements are inspired, some are not, and no one can tell the difference, it's like playing Balderdash with Scripture: the right answer is in there, but there are a lot of convincing wrong answers.
- This latter view also has Scriptural support: Acts 15:6-7 describes the Apostles and presbyters in a big debate over whether or not circumcision is required for salvation. It seems to me unlikely that all Twelve were (initially) on the same side of the debate, because if they were all unified, I imagine most presbyters would have faithfully submitted (although maybe not: Acts 11:2 involves Peter getting in trouble for eating with the Gentiles, probably the reason for his cowardice in Galatians 2:11). It'd take sort of a hardheaded presbyter to stand up to all Twelve of them. So assuming that they were in initial disagreement, they ended with infallible and divinely inspired agreement. This seems to suggest individual Apostolic fallibility and corporate Church infallibility. By this standard, the Scriptures aren't known to be inspired just because they were written by the Apostles, but because they were confirmed by the Church (first, through Tradition; later, through the Magisterium).
Either of these views, or some combination thereof, may be true. For example, privately held beliefs of popes can still be wrong - perhaps the same was true of privately held beliefs of Apostles, and it took the Holy Spirit-inspired Council to sort it out, even while He assured that these errant views never tainted their public teaching? That would harmonize the two views.
But they don't have to be true. The Holy Spirit was able to inspire Baalam's donkey to speak infallibly (Numbers 22:28). The rest of the time, it was still a total... donkey. So while I happen to think the Church is infallible, it doesn't have to be. The real reason that this argument from causality is wrong is because we believe the Scriptures are "God-breathed," so the infallible cause leading to the inspired effect is the Holy Spirit, not the Church or the Apostles. The Apostles did err, members of the Church err, popes err, etc. The reason that papal and Church infallibility exists, and the reason the Apostolic writings were inspired and infallible (on issues of faith and morals), is because they're the instruments the Holy Spirit deigns to use. Certainly, if the Holy Spirit used random agents and in an inconsistent way, it would be harder to determine inspired or infallible statements from non-inspired or non-infallible. But those are reasons why Church infalliblity is a good idea, not why it's logically necessary.
All that said, Peter Kreeft is a brilliant thinker, and I strongly encourage you to check him out. The article I'm quoting from here is from 1988, so it's possible that I'm either misunderstanding what he's saying or that he's moved on since then. Otherwise, it's just like a good pitcher throwing an occasional wild pitch.