Let’s consider how the early Christians became Catholic, or how the Catholic Church came into being. Before formalization of the canon, there was no New Testament; indeed, there was no Bible. Did these individuals become Catholic because of "private interpretation?? Interpretation of what? All they could interpret was what someone told them orally. If they understood it wrong, they could appeal to those who had authority by Christ to interpret (i.e. the primitive magesterium). That authority didn’t vanish with the death of the apostle John, Clement of Rome, or any of the others. It was passed on as the living magesterium. It was only after there was a written word that that particular argument seems to make any sense. And if that were the case, then the only “true Catholics” would have been those who never had a Bible, or at least couldn’t read it due to illiteracy or ignorance. Therefore, “private interpretation” isn’t the only way to entry into the Catholic Church. There are lots of “true Catholics” (regardless of how that term is defined by someone like Svendsen) who became Catholic without the benefit of a Bible, both in modern times and ancient times. This argument is based on the assumption that the only source of truth and authority (as the Bible apparently can interpret itself in the mind of some individuals), lies in the Bible. However, as Catholics, we know this is a false premise. Therefore, anything that follows from it is moot. Unless I’m understanding the premise wrong, this argument doesn’t seem to hold water.