The question then, is this: when two teachings of the Magisterium exist in apparent contradiction of each other, what is a would-be faithful Catholic to do?

On the one hand, Humanae Vitae upheld a long tradition of opposition to contraception. On the other, NFP appears on its face to be contraceptive, and only some fairly clever (and I do not intend that word approvingly) reasoning can get one to the conclusion that it is not. And yet NFP appears to be an ordinary and universal teaching of the Magisterium. The tradition of the church is that Catholics are bound to follow such teachings, but to follow them to their logical end would itself lead one to a marriage of total abstention from sex, or sexual activity with such frequency as to interfere with ordinary life. Either an invalid marriage or an unchaste one.

This is the difficulty, and I know not what to make of it.