Originally published as a 24-week correspondence course, The Master Key System is a step by step process for achieving the life and success that youve always desired. Using the creative power of thought, Charles F. Haanel guides readers to understand and harness their own mental power in order to manifest the life they wish to experience. Each of the 24 lessons includes study questions and responses to deepen your understanding of the material. Practical and accessible, The Master Key System is a transformative guide to living a fulfilling, successful life. The Master Key System is part of the GPS (Good, Practical Simple) Guides to Life series, which aims to introduce a new audience of readers to the life changing writings of past generations. This new edition also includes the bonus book Mental Chemistry also by Haanel.