which is the proper understanding of infallibility?

[linate]

ive seen two understandings of how error is supposed to be kept out of the catholic church. one is that the pope is prevented by the holy spirit from teaching error. another is that if the pope teaches error, he is automatically not pope any more. ive seen devoted catholics adhere to both systems. 

which is it? i'm pretty sure it's the first one, but am curious how many folks say the second. 

[chrysostom]

If a pope invokes the very very specific conditions required for infallibility as stated by Vat I then he is indeed protected from error. St JPII may have done so with Familiaris Consortio but other than that I don't know of any instance post VII of these conditions being invoked - someone please correct me if I'm wrong. It logically follows that outside those very specific circumstances infallibility is not guaranteed. That should not be controversial.

I think that if a Pope were to attempt to issue an infallible decree denying, say, the Resurrection, it would not happen - God would actually prevent him. He would not be able to do it.

[vee]

The basic understanding is that I’m always right