I heard Robert McChesney tell this Neil Postman story during a lecture earlier this week. The story appears to have originated with the psychologist Gordon Allport. Its point: there's no such thing as a neutral question:
The form of a question may ease our way or pose obstacles. Or, when even slightly altered, it may generate antithetical answers, as in the case of the two priests who, being unsure if it was permissible to smoke and pray at the same time, wrote to the Pope for a definitive answer. One priest phrased the question "Is it permissible to smoke while praying?" and was told it is not, since prayer should be the focus of one's whole attention; the other priest asked if it is permissible to pray while smoking and was told that it is, since it is always appropriate to pray.
Neil Postman, Technopoly: The Surrender of Culture to Technology (New York: Vintage, 1993), 125–26