Charles F. Haanel

Charles F. Haanel (1866–1949) was an American businessman, author, and publisher of German descent. He later focused primarily on philosophy, psychology, and personal development. He became known for The Master Key System (1916). His other published works include Mental Chemistry (1922), New Psychology (1924), and A Book About You (1927). He also co-authored The Amazing Secrets of the Yogi (1937) with Victor Simon Perera.