Talking About Whom?
He is the sole guardian of truth; debate is pointless; all that is required is obedience;
He's complaining about how some Catholics take the word of others (in this case, Cardinal Ratzinger) and take it dogmatically.
Of course, the above quote can also be applied to the gawd Catholics worship as well. In fact, it applies perfectly and completely. You can't argue or debate with an entity you believe is omiscient; the act would be pointless. All that matters is obedience and faith in that entity's word.
And attributing that to an entity such as Gawd is a far more troubling and fundamental belief than attributing it to a human. It says humans can't (and therefore shouldn't) reason with the entity that matters the most...that Gawd is above reason and logic.