Responsible judgment

     "This should teach us never to judge the actions of our neighbor without having reflected very well beforehand.  Even then, of course, we are only entitled to make such judgments if we are responsible for the behavior of the people concerned, that is, if we are parents or employers [(pères et mères, les mâitres et mâitresses)], and so on.  As far as all others are concerned, we are nearly always wrong."

     St. John Vianney, Sermon for the Eleventh Week after Pentecost, On rash judgment.  The sermons of the Curé of Ars, trans. Una Morrisy (Chicago:  Henry Regnery, 1960), 40.  =Sermons (Lyon:  1883), vol. 2, pp. 409-410, italics mine.

Ce qui doit nous porter à ne jamais juger des actions de notre prochain sans avoir bien réfléchi auparavant, et encore, seulement lorsque nous sommes chargés de la conduit de ces personnes, comme pères et mères, les mâitres et mâitresses; mais, pour toute autre personne, nous faisons Presque toujours mal.

That's clearly the passage in question.  And yet the translation has to be doing some unmarked selection, as the rest of the surrounding text in English isn't just right there.  (The closing prayer of King David on p. 41 appears, e.g., a full three or four pages later, on p. 413 of the French.)

     But in any case, note that Vianney speaks only of the extreme difficulty ("nearly always") of judging accurately in cases for which we bear no responsibility.  It would be interesting to see how this gets fleshed out in the larger context of the whole of his sermons, e.g. in his opposition to dancing and such.