Born in St. Louis, Missouri, in 1885, Robert Collier trained to become a priest early in his life, before settling on a career in business, achieving success in the fields of advertising, publishing, and engineering. After recovering from chronic illness with the help of mental healing, Collier began studying New Thought, metaphysical, and success principles. He distilled these principles into a popular and influential pamphlet series, collected into a single volume as The Secret of the Ages in 1926, and later revised by Collier in 1948. He died in 1950.