Consider the age in which we live. It wants magicians…. A scientist tells people the truth. When times are good—that is, when the truth offers no threat—people don’t mind.… A magician, on the other hand, tells people what they wish were true—that perpetual motion works, that cancer can be cured by colored lights, that a psychosis is no worse than a head cold, that they’ll live forever. In good times magicians are laughed at. They’re a luxury of the spoiled wealthy few. But in bad times people sell their souls for magic cures and buy perpetual-motion machines to power their war rockets.
Source: Heinlein, Robert A. (ed.), Tomorrow, the Stars, p. 207. SBN 425-01426-6, Doubleday & Company, Inc.