When a patron called our Reference Desk last night to confirm the author of the famous saying, we were surprised with the result after consulting Burton Stevenson's The Home Book of Proverbs, Maxims, and Familiar Phrases. According to this hefty text of quotations and their origins, Archbishop Richard Whately is the man behind the phrase. In part II, chapter 18 of his Thoughts and Apothegms, he wrote, "Honesty is the best policy, but he who acts on that principle is not an honest man."
To learn more about Whately, click here! Or click here to reserve a copy of his biography, A Protestant in Purgatory: Richard Whately, Archbishop of Dublin.