Is There a Source of the Big Bang Theory?

The modern cosmos, as we now know it, was first born in the mind of a Catholic priest. It's always risky to try to do sort of counterfactuals or figure out what it was that allowed him to have this idea when others didn't at the same time. But I think we can at least speculate that people who are wedded to the idea of an infinite universe in time, which was the case for most physicists at the last turn of the century, would be more of a barrier to getting from theories and observations with a beginning.