"All Is Not Gold That Glitters"
Context: None will ever know who originated the idea we express as "All that glitters is not gold." Perhaps it was the first prospector fooled by the iron pyrites we now call fool's gold. The aphorism appears in many languages. Alanus de Insulis, who died in 1294, wrote in his Parabolae: Non teneas aurum totum quod splendet ut aurum (Do not hold as gold everything that shines like gold). Chaucer in The House of Fame (1374-1385) wrote in Book I, line 272: "Hyt is not all gold that glareth." Dryden in The Hind and the Panther (1687) put it in the form with which we are familiar. Sancho Panza piles one aphorism on another to explain to the Duchess why he loyally serves Don Quixote, despite his master's apparent madness:
. . . if you don't think fit to give me an island because I am a fool, I'll be so wise as not to care whether you do or no. 'Tis an old saying, the Devil lurks behind the cross. All is not gold that glisters. From the tail of the plough, Bamba was made King of Spain; and from his silks and riches was Rodrigo cast to be devoured by the snakes. . . .