I often comment over at Called to Communion, a website managed by former Reformed guys, mostly philosophers and ex-clerics, who seek to present Catholic truth in a way that they hope would be persuasive to some of their erstwhile co-religionists. The project is impressive. Some of the longer articles are of peer-review quality and are developing what is, in effect, a Catholic ecclesiology framed to address directly the issues of most concern to "confessional" Protestants. Other articles are more polemical, usually rebutting some Protestant objection that was, or has become, standard. I once thought I'd heard them all in my time, but I soon learned at C2C that I haven't. The most interesting I've heard lately is framed, for purposes of rebuttal, by Bryan Cross in his article The Tu Quoque.
To present the issue fairly, I must quote the first three paragraphs of his post in full, but without the footnotes you can track at C2C:
In various places I have argued previously that without apostolic succession, creeds and confessions have no actual authority. They have no actual authority apart from apostolic succession because without apostolic succession the only available basis for a creed or confession’s authority is the individual’s agreement with the interpretation of Scripture found in that creed or confession. Each person picks the confession of faith that most closely represents his own interpretation of Scripture. If his interpretation of Scripture happens to change, he is not bound by his prior choice of confession; rather, he simply picks a different confession that more closely matches his present interpretation. I have described this as painting one’s magisterial target around one’s interpretive arrow, i.e. the practice of choosing and grounding magisterial authority based on its agreement with one’s own interpretation of Scripture.
But an important principle regarding authority is this: “When I submit only when I agree, the one to whom I submit is me.” In other words, agreement with oneself cannot be the basis for authority over oneself. Therefore a creed or confession’s agreement with one’s own interpretation of Scripture cannot be the basis for its authority. And this is why without apostolic succession, creeds or confessions have no actual authority. That is a simple overview of the authority argument.
The primary objection to this argument is the tu quoque [lit. you too] objection, namely, that the person who becomes Catholic upon determining that the Catholic Church is the Church that Christ founded is doing so because the Catholic Church most closely conforms to his own interpretation of Scripture, history and tradition. In other words, in choosing to become Catholic, he has simply chosen the ‘denomination’ that best conforms to his own interpretation of Scripture, tradition and history. Hence if Protestant confessions have no authority over the individual Protestant because Protestants select them on the basis of their conformity to their own interpretation of Scripture, then neither does the Catholic Church have any authority over the person who becomes Catholic, because Catholics select the Catholic Church on the basis of its agreement with their own interpretation of Scripture, history, and tradition. But if choosing the Catholic Church on the basis of one’s own interpretation of Scripture, history, and tradition does not undermine the authority of the Catholic Church, then neither does choosing a Protestant confession on the basis of one’s own interpretation of Scripture undermine that Protestant confession’s authority. In other words, just as the person becoming Catholic claims to have discovered that those in the magisterium of the Catholic Church are the successors of the Apostles, and thereby bearing divine authority, so the person adopting a Protestant confession believes he has discovered that this particular confession is in agreement with Scripture, and thus that this confession derives its authority from Scripture. But if picking a confession on the basis of its agreement with one’s own interpretation of Scripture entails that this confession has no authority over oneself, then picking the Catholic Church on the basis of its agreement with one’s own interpretation of history, tradition and Scripture entails that the Catholic Church has no authority over oneself. In short, the conclusion of the tu quoque objection is that either the Catholic Church likewise has no authority, or the Protestant confessions can truly have authority.
Of course the objection is unsound, and Bryan's post goes on to do a good job of showing why. So his rebuttal is what I offer you as the remainder of this post.