In this four class series Geshe Michael Roach & Lama Christie McNally will present an overview of the four chapters of Master Patanjali's Yoga Sutra. The Yoga Sutra of Patanjali is a classic Sanskrit treatise consisting of 195 threads, or aphorisms, describing the process of liberation through yoga. Although little is known about Patanjali (most scholars estimate that he lived in India circa 200-300 b.c.), his writings have long been recognized as a vital contribution to the philosophy and practice of yoga.