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Which document defined papal infallibility at the First Vatican Council?
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papal infallibility
In 1869 Pope Pius XI (center) convened an assembly of bishops that became known as the First Vatican Council (or Vatican I). The council declared the dogmas of papal primacy and papal infallibility before the assembly was suspended indefinitely in 1870.
The document that defined papal infallibility at the First Vatican Council was the dogmatic constitution Pastor aeternus. This council, which took place from 1869 to 1870, was convoked by Pope Pius IX. The doctrine of papal infallibility states that the pope, when acting as the supreme teacher and under specific conditions, cannot err in matters of faith or morals. This means that when the pope makes a definitive statement on faith or morals, intended to be held by the entire Church, he is preserved from error by divine assistance.12345