Robert Collier (1885-1950) was an American author of self-help and New Thought metaphysical books in the 20th century. He is best known for his book 'The Secret of the Ages' (1926), which has sold over 300,000 copies and has been heralded as a cornerstone in the self-improvement genre. 'The Greatest Works of Robert Collier' is a compilation of his most seminal texts, offering a comprehensive look into the ideas and philosophies that underscored his work. Collier's writing style is characterized by a persuasive, conversational prose that seeks to empower individuals to tap into their subconscious minds and utilize the power of thought to achieve success and fulfilment. His books blend a practical approach to problem-solving with a deep-seated belief in the potential for human growth and the realization of personal aspirations. Often drawing on historical examples and his own life experiences, Collier's work continues to influence contemporary motivational and self-help literature. While 'The Secret of the Ages' remains his most prominent work, his contributions through various other texts have cemented his reputation as a significant figure in the genre of personal development and success literature.