Catholic apologists are doing a fine job refuting those who have a “no authority but the Bible” understanding of sola scriptura. But I am encountering people who say, “I admit the Church and the early Fathers have real authority, but not infallible authority, which is something only the Bible has.” This understanding sounds more formidable. If we argue against just the first understanding then we look like we are attacking a straw man. What do you recommend?
Let's call the first view sola-1 and the second sola-2. I don’t know how others handle this, but whenever I discuss sola scriptura, I try to throw in a qualifying adjective like decisive or binding to cover the “sola-2” view. Thus, I’ll say that sola scriptura is the view that “nothing besides Scripture has binding or decisive authority.” This makes it clear that it is the sola-2 view I’m talking about and avoids the charge of attacking a straw man.
Frankly, though, there is little difference between the arguments that succeed against sola-1 and sola-2. Advocates of sola-2 may sound at first like they have a more formidable view, and they often claim that they have a more “historic” view, but on the level of argument, all that is just packaging.
This becomes clear when one asks what kind of authority the church or the Fathers are supposed to have. It clearly isn’t binding or decisive authority. At most, in the Protestant view the teachings of Protestant churches and the Fathers could suggest beliefs and interpretations to one, but never bind one to believe them. Only the Bible can do that. Some Protestants might even go so far as to say that we owe church leaders, confessions, and Fathers some kind of deferential preferment, but they ultimately cannot tell one what to believe.
As long as that is the case, sola-2 is in agreement with sola-1 in placing church leaders, confessions, and Fathers on the same plane as commentaries, Bible dictionaries, and other study tools. They are things that can suggest but not require belief. The writings of Augustine may (or may not) be considered more prestigious as study tools than Unger’s Bible Handbook, but that’s all they are for Protestants: study tools. You are still left to make up your own mind on every point of theology.
As a result, the same arguments that work against sola-1 generally disprove sola-2 as well. Some Protestant apologists may try to dress up their sola scriptura in new clothes so they can boast of being more “historic” and start throwing around charges of straw men. But ultimately it’s the same thing, and the same arguments work against it.