It is a good question, and an honest question that many may wonder about, both inside and outside the Catholic orbit. I wince at the "social" qualifier," but Joe Carter, a Baptist, poses the questions well at the First Things blog:

If you had asked me as a young Baptist boy to explain the difference between Protestants and Catholics, I would have said that Catholics were the Christians who have to do what the Pope tells them to do. Now Im an old Baptist and realize how naive I was. (Im more likely to agree with the Pope than some American Catholics I know.)Im still unclear, though, on where Catholics draw the line of demarcation between complete freedom of conscience and deference to magisterial authority. After all, if a Catholic can support abortion and still receive communion, what is off-limits?

Stephen M. Barr responds with a useful (to my layman's eye) explanation, and this caveat:

I do think that it would be better if Catholics were not so disposed to pick these documents apart like an English teacher grading a student paper. A little more obsequium would be nice, even as we recognize that not everything in these documents is of equal weight.

I wonder if Jody Bottum, who is diligently deconstructing and re-writing Caritas in Veritate in a series on posts, caught that monito.I very much like the writings of RichardGaillardetz on authority, but I'd welcome other amplifications. Of course any concession to different levels of authority opens the gate to the slippery slope to dreaded cafeteria Catholicism. But it's interesting to see many who would confer the status of near-infallibility on lesser papal statements they like nowpick apart a major statement they don't like quite so much. So say we all, eh.