I found this in a very interesting book about World War II: World War II; Opposing Viewpoints, William Dudley, Ed. American History Series. San Diego: Greenhaven Press, 1997. Emphases mine.
"It is of the utmost importance that the people of this country, with the best information in the world, think things through. The most dangerous enemies of American peace are those who, without well-rounded information on the whole broad subject of the past, the present, and the future, undertake to speak with assumed authority, to talk in terms of glittering generalities, to give to the nation assurances or prophesies which are of little present or future value."
September 3, 1939; fireside chat by President Franklin Delano Roosevelt