Master Mind: The Key to Mental Power Development and Efficiency distills Atkinson's New Thought into a compact course on attention, will-training, habit, suggestion, and directed imagination. In crisp, didactic prose, it interleaves brief theory with graded exercises cultivating concentration, self-control, and mental economy. Framed by the Progressive Era's efficiency craze and popular psychology, it translates metaphysical "mind-power" into practical self-mastery, linking character formation to measurable results in work and conduct. William Walker Atkinson (1862–1932) was an attorney, publisher, and influential New Thought writer, prolific under his own name and as Theron Q. Dumont and Yogi Ramacharaka; he is often credited as a principal behind The Kybalion. By his own account, recovery from professional burnout led him to autosuggestion, occult psychology, and yogic discipline—an eclectic formation that shapes the book's blend of businesslike clarity with esoteric confidence in the mind's plasticity. Master Mind merits attention from scholars of self-help and from practitioners seeking disciplined mental training. Read it as both historical document and workbook: its concise drills in attention, habit, and will offer durable techniques, while its context illuminates how early twentieth-century metaphysics fed the modern culture of productivity and ethical self-governance. Quickie Classics summarizes timeless works with precision, preserving the author's voice and keeping the prose clear, fast, and readable—distilled, never diluted. Enriched Edition extras: Introduction · Synopsis · Historical Context · Brief Analysis · 4 Reflection Q&As · Editorial Footnotes.