Galileo could have gone even further if his own devout Catholicism-which was unwavering in spite of his being persecuted by those he trusted the most-held him back from coming up with a theory of gravitation. Similarly Cuivier, the greatest biologist between Linnaeus and Darwin, might have come up with the theory of evolution if his own pious Christianity hadn't prevented him from doing so.
Good points. And, as a young man, Darwin was himself a pious believer; had his curiosity and his intellect been weaker, he might never have recognized what his eyes and his notebooks were telling him during and after the voyage of the Beagle.