The Master Key System

The Master Key System by Charles F. Haanel (1912)

A 24-week course in mental science, originally distributed as a correspondence course. Haanel teaches that thought is creative energy and that disciplined thinking can achieve any goal. The book that allegedly inspired Bill Gates.

Historical Significance:
Charles F. Haanel, a St. Louis businessman, created The Master Key System as a mail-order course in 1912, later published as a book in 1916. Legend holds that a young Bill Gates read it at Harvard before dropping out to start Microsoft — though Gates has never confirmed this. What is confirmed is that Rhonda Byrne cited Haanel alongside Wallace Wattles as primary inspirations for The Secret. The Master Key System was banned by the Catholic Church in 1933, which only increased its underground popularity. Each of the 24 chapters ends with a practical mental exercise — a structured meditation program that anticipated modern mindfulness practices by a century.

This public domain classic was originally published in 1912. Free to read and share.