There’s been some Facebook and blogging debates going on about the authority of the teaching of the Church and infallibility. Unfortunately, some of this discussion is muddled because of a confusion of two issues: The issue of obedience and the issue of infallibility. Some, in attempting to argue against obedience to the Church in an issue they dislike, try to explain away binding authority this way. They begin by pointing out that the ordinary magisterium is not formally protected from error in the same way that an ex cathedra statement is protected. They point out that technically, the rest of the Church teachings are non infallible. Now that is true. The ex cathedra statement is a special magisterial action, and it has special protections, given the level of authority they invoke.
But, then the fallacy of equivocation comes into play. Because the teachings of the ordinary magisterium are non infallible, it is argued that they are in fact “fallible,” and the word is stretched into the claim that the Pope or the bishop is teaching error and must be resisted. That is a distortion of the Church teaching. Everything that was eventually defined infallibly by the Church was previously taught by the ordinary magisterium. The infallible definition essentially made the ordinary magisterium more specific. But people were still obligated to obey the ordinary magisterial teaching before it was defined ex cathedra.