In *The Power of Concentration (Complete Edition)*, William Walker Atkinson presents concentration as the central discipline through which thought, will, character, and practical achievement may be deliberately shaped. Combining psychological instruction, New Thought metaphysics, moral exhortation, and carefully sequenced exercises, the book addresses attention, mental imagery, self-command, persistence, and the elimination of distraction. Its prose is direct, aphoristic, and methodical, frequently addressing the reader in an encouraging imperative voice. Literary rather than scientific in its evidentiary standards, the work belongs to the early twentieth-century self-culture tradition, where spiritual philosophy and popular psychology converged in the promise of individual transformation. Atkinson (1862–1932) was a prolific American writer, lawyer, businessman, and influential figure in the New Thought movement. Writing under his own name and several pseudonyms, he helped popularize a synthesis of mesmerism, mental healing, Eastern-inflected philosophy, and practical success literature. His interest in concentration reflects the period's broader fascination with the power of mind, personal agency, and disciplined self-improvement, while also revealing the era's characteristic tendency to translate spiritual principles into techniques for everyday life. Readers interested in the history of self-help, New Thought, or modern ideas of productivity will find this volume especially rewarding. Its exercises invite practical experimentation, while its idealistic claims encourage critical reflection on the relationship between attention and achievement. The book is best approached both as a historical document and as a sustained manual of mental discipline.