Quadragesimo Anno §8

⁸ The wise Pontiff long weighed all this in his mind before God; he summoned the most experienced and learned to counsel; he pondered the issues carefully and from every angle. At last, admonished "by the consciousness of His Apostolic Office" lest silence on his part might be regarded as failure in his duty he decided, in virtue of the Divine Teaching Office entrusted to him, to address not only the whole Church of Christ but all mankind.