While reading through Casti Connubii for quite a different purpose, I happened upon this:
104. Wherefore, let the faithful also be on their guard against the overrated independence of private judgment and that false autonomy of human reason. For it is quite foreign to everyone bearing the name of a Christian to trust his own mental powers with such pride as to agree only with those things which he can examine from their inner nature, and to imagine that the Church, sent by God to teach and guide all nations, is not conversant with present affairs and circumstances; or even that they must obey only in those matters which she has decreed by solemn definition as though her other decisions might be presumed to be false or putting forward insufficient motive for truth and honesty. Quite to the contrary, a characteristic of all true followers of Christ, lettered or unlettered, is to suffer themselves to be guided and led in all things that touch upon faith or morals by the Holy Church of God through its Supreme Pastor the Roman Pontiff, who is himself guided by Jesus Christ Our Lord.
While this will evince chagrin or excite anguish or rattle the cage of almost no one who passes through this way, I suspect that it would stick mightily in the craw of those who would prefer to pick and choose amongst the truths to which they wish to adhere. I wonder how many of us, even those in agreement with the sentiment, live the actuality of the final sentence in the excerpt above? I know that I truly do believe and hold true all that the Church teaches (in my very meager ability to comprehend it), and even so, practice differs from belief. Perhaps it is the road that transforms what is held intellectually into what is lived in reality that is the hardest road to walk.