The 1951 Address, and a Priest Asking a Pope to Stop

On 22 November 1951 Pope Pius XII addressed the Pontifical Academy of Sciences on the proofs of the existence of God in the light of modern natural science. Drawing on the expanding universe and on the age estimates then current, he argued that science had arrived at a moment when the cosmos began, and that this pointed to a creation and therefore to a Creator. It was reported around the world as the church endorsing the new cosmology.

Lemaitre, who was a member of the Academy and whose hypothesis was being used, thought this was a mistake, and said so. His consistent position was that the primeval atom was a physical hypothesis, that it stood or fell on physical evidence, and that it was entirely outside any metaphysical or religious question. The beginning of the expansion was not the creation of Genesis, and to bind a doctrine to a scientific model was to leave the doctrine hostage to the next observation. He put the case to the pope through the director of the Vatican Observatory, Daniel O'Connell, and the two men spoke with Pius XII.

Pius XII addressed the International Astronomical Union in Rome the following September and did not repeat the argument. The atlas records the episode because both parties behaved better than the story usually allows: a pope who was told he had overreached and dropped it, and a priest who declined to let his own theory be used as an apologetic when he thought the use was unsound.