Hatha Yoga: Or The Yogi Philosophy of Physical Well-Being (1904) by Yogi Ramacharaka—the pseudonym of American author William Walker Atkinson—is a foundational text introducing the principles of Hatha Yoga to Western readers. More than a manual of postures or breathing techniques, the book presents yoga as a holistic philosophy of health, uniting body, mind, and spirit.

Ramacharaka explains the body as the sacred vehicle of the soul and emphasizes the importance of maintaining physical harmony through correct breathing, diet, relaxation, and mental control. He teaches that health is not merely the absence of disease but the balanced expression of vital energy (prana). Through simple yet profound exercises, the author guides readers toward physical vitality, emotional calm, and spiritual awareness.

The work also dispels misconceptions about yoga, framing it not as a system of contortion or asceticism but as a science of life rooted in natural law and self-discipline. Blending Eastern philosophy with practical instruction, Hatha Yoga became one of the earliest and most influential works to popularize yoga in the English-speaking world, inspiring generations to view physical well-being as the first step on the spiritual path.