Paul Klee, best known for his mastery of color and semi-abstract patchwork paintings of squares, completed more than 10,000 paintings, drawings, and etchings during his life. His work is difficult to classify but widely admired and highly sought after. Carl Djerassi, scientist, novelist, philanthropist, most famous for inventing the birth control pill, was a great fan of Klee and amassed one of the most important private collections of his work in the world. This catalog reproduces highlights from the collection, now owned by the San Francisco Museum of Modern Art, including full-color images of nearly one hundred rarely published works. These drawings, sketches, gouache and watercolors reflect the whole of Klee's short but prolific career and are among his most beautiful and important works. The text includes background and critical commentary from noted Klee experts. In addition, an interview with Djerassi reveals his artistic endeavors and passion for Klee, a creative genius whose energy, versatility, productivity, and vision speak volumes to the scientist and anyone interested in the inventive power of the imagination.