The Pope said that the apparent organization that characterizes the entire universe was another indication. It appears that Pius XII's underlying assumption was that the supernatural act of divine creation began with the early stages described by the primeval atom hypothesis:
. . . contemporary science, with one sweep back across the centuries, has succeeded in bearing witness to the august instant of the primordial Fiat Lux, which along with the matter there burst forth from nothing a sea of light and radiation . . . Thus, with that concreteness which is characteristic of physical proofs, modern science has confirmed the contingency of the universe and also the well-founded deduction to the epoch when the world came forth from the hands of the creator.
Statements such as these contradicted Lemaître's own strict distinction between the tools for investigating matters of science and matters of theology. ... Not surprisingly, Lemaître was alarmed when he was informed that the Holy Father would be delivering a speech to the Eighth General Assembly of the International Astronomical Union in Rome. On a trip to South Africa, Father Lemaître stopped at the Vatican to consult with two men, Father O'Connell, a science advisor to Pius XII, as well as the Cardinal Secretary of State. Lemaître's visit had the intended effect. ... Pius XII never mentioned the primeval atom hypothesis again.