Leo Robert Collier, born in 1885, was an American author prolific in the self-help and New Thought movements during the 20th century. He was connected to the publishing family behind Collier's Weekly. Collier dedicated much of his life to writing, editing, and research, developing a focus on the practical psychology of achieving abundance, manifesting desires, the power of faith, visualization, and confident action for personal development. His metaphysical writings centered on the mind's potential and the principles of positive thinking to attain success.

His influential book, "The Secret of the Ages" (1926), achieved significant sales, exceeding 300,000 copies during his lifetime. Collier's work experienced a resurgence in popularity, partly due to its mention in the metaphysical film "The Secret." His legacy continues through Robert Collier Publications, Inc., maintained by his family. Beyond his books, Collier also published a monthly magazine, "Mind, Inc.," which evolved over time, shifting from a mix of fiction and religious material to a focus on other content.

Robert Collier's literary contributions were deeply rooted in the principles of New Thought and metaphysical philosophy, emphasizing the power of the human mind to shape reality. His writings explored concepts such as the practical psychology of abundance, the manifestation of desires, the role of faith, and the effectiveness of visualization techniques. Collier advocated for confident, decisive action as a crucial component in achieving personal success and fulfillment. His core message revolved around the idea that positive thinking and a focused mental state could unlock an individual's potential for prosperity and well-being. He aimed to provide readers with actionable strategies derived from these metaphysical concepts to improve their lives.

Collier began his professional journey in the advertising industry, honing his skills as a copywriter before establishing his own agency. He gained recognition for his expertise in direct-response marketing, particularly for his persuasive letter-writing techniques. This expertise culminated in "The Robert Collier Letter Book," first published in 1931, which became a foundational text for copywriters and marketers. The book compiles effective letters and strategies for various purposes, including sales and relationship building, highlighting Collier's conversational and persuasive writing style that prioritized understanding the audience's needs. In addition to his books, Collier also founded and published "Mind, Inc.," a magazine that began in 1929, initially featuring a blend of fiction and religious content before evolving its focus.