This was pretty much the opposite of Acton's view. When Creighton asked Acton to review the book, Acton gave Creighton's book a fairly negative view without getting into the reasons for it; but he mentioned in a letter that the result of the difference of opinion here was due to differences in their philosophy of history. Creighton, who had been taken aback by the review, replied that he wished Acton would take the trouble at some point to explain his philosophy of history; and the long letter in early April of 1887, in which the famous phrase appears, is devoted to laying out Acton's philosophy of history, one in which moral principles play the key role in making Acton's view almost the opposite of Creighton's view (which would probably be pretty commonly accepted by historians today). I can't find the full letter online, but you can get something of a taste for it with the following selection:
Life and letters of Mandell Creighton, D.D. Oxon. and Cam., sometime bishop of London ... By Louise Creighton
Creighton's response is just as interesting, and can be found at the same link. To a third party Creighton summed up the issue as he saw it:
Life and letters of Mandell Creighton, D.D. Oxon. and Cam., sometime bishop of London ... By Louise Creighton
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* ADDED LATER: Acton's difficulties with the notion of Papal Infallibility were actually closely related to this topic, as Creighton recognized; Acton argued for fallibilism on the basis of the moral judgment of history. He feared that the doctrine of infallibility involved being indulgent toward terrible evils committed by past popes. Newman had much the same problem with the doctrine; after the Council he accepted the definition on the authority of the Church, but confessed that he didn't know how to reconcile it with certain historical facts. Acton was somewhat less yielding on the matter, in part because he had spent much, much more of his life on the issue.