Allen's writings highlight the transformative power of thought in enhancing one's potential. While he may not have attained significant fame or riches during his lifetime, his insights continue to resonate globally, especially within the New Thought movement. His renowned work, 'As a Man Thinketh', released in 1902, stands as a cornerstone in self-help literature. At its core, the book emphasizes that uplifting thoughts mold an honorable individual, whereas negative thoughts lead to a disheartened existence.