I flipped open Alex Osborn's (creator of Brainstorming and founder of the Creative Education Foundation and their annual Creative Problem Solving Institute over 40 years ago), Wake Up Your Mind, published in 1952 and found this week's Creativity Challenge.

In his Copyright sources quoted list he included...
 
Robert P. Crawford's THINK FOR YOURSELF, 1929
 
Enest Dimmet's THE ART OF THINKING, 1929
 
Hughes Mearns' CREATIVE POWER, 1929
 
Graham Wallas' THE ART OF THOUGHT, 1926

This week's challenge is to go to your library, real or virtual, and find the oldest book about creative thinking or creativity and read at least one chapter, perhaps even take it home and read it from cover to cover.