[quote="Lief_Erikson, post:1, topic:180293"]
When the Vatican canonizes somebody a saint, is that declaration infallible? Is there any possible legitimate doubt left about the eternal destiny of the person who's been canonized?
I'm just curious what the official Church position on this is, so if anyone could provide a source from Church documents on the matter, I'd appreciate it. Thanks :).
Yes, when the Holy Father declares a person to be a saint, it's an exercise of papal infallibility.
See this essay that references Church documents, as well as a section in the Catholic Encyclopedia (scroll down for the appropriate section) that noted many other Church fathers and theologians concur on this as well.
Not all saints have this mark of infallibility, as the first and earliest saints in Catholic history became known by general acclamation--that is, popular opinion deemed the individuals as saintly. And the Orthodox Churches have made other people saints that aren't recognized by their Western Church.