33 Then the philosopher must come in again to impose on the historian the obligation of following in all his studies the precepts and laws of evolution. It is next for the historian to scrutinise his documents once more, to examine carefully the circumstances and conditions affecting the Church during the different periods, the conserving force she has put forth, the needs both internal and external that have stimulated her to progress, the obstacles she has had to encounter, in a word everything that helps to determine the manner in which the laws of evolution have been fulfilled in her. This done, he finishes his work by drawing up in its broad lines a history of the development of the facts. The critic follows and fits in the rest of the documents with this sketch; he takes up his pen, and soon the history is made complete. Now we ask here: Who is the author of this history? The historian? The critic? Assuredly, neither of these but the philosopher. From beginning to end everything in it is a priori , and a priori in a way that reeks of heresy. These men are certainly to be pitied, and of them the Apostle might well say: They became vain in their thoughts. . . professing themselves to be wise they became fools ( Rom . i. 21, 22); but, at the same time, they excite just indignation when they accuse the Church of torturing the texts, arranging and confusing them after its own fashion, and for the needs of its cause. In this they are accusing the Church of something for which their own conscience plainly reproaches them.
Source: Pascendi Dominici Gregis (Vatican.va)