-Jane Austen, several of her collected works
Many a character in Jane Austen novels uses this phrase as a sort of rhetorical time-buyer; that is to say, they use this phrase when they are trying to say something important that could be misconstrued in a more clear, yet just-as-socially-polite-and-seemingly-neutral, way. If my memory serves me right, only the heroes and heroines use this phrase. Probably because only the heroes and heroines see fit to be intentional and thoughtful with their words. The Mr. Elliots don't bother with clarification because they never think of anyone but themselves.