Charles F. Haanel

Charles F. Haanel (1866-1949) used the concepts and methods found in The Master Key System to create a successful business career in St. Louis, Missouri, where he eventually founded one of the largest conglomerates of his time. As well as being an active member of the American Scientific League and the American Society for Psychical Research, he wrote several bestselling books focusing on his business techniques. Besides The Master Key System, he also wrote Mental Chemistry and The New Psychology. Known as the "father of personal development," Haanel has revolutionized conventional thought for almost one hundred years.