The Importance of Being Earnest act 1 (1895). The same lines appear, as a dialogue between Lord Illingworth and Mrs. Allonby, in A Woman of No Importance, act 2 (1893).
Henry Ward Beecher (1887). “Beecher : Christian Philosopher, Pulpit Orator, Patriot and Philantropist: A Volume of Representative Selections from the Sermons, Lectures, Prayers, and Letters of Henry Ward Beecher”