The present volume provides a learned commentary on the second chapter of the Yoga-Sutra. From a traditional perspective, it is as original, broad, bold, and awe inspiring a commentary as Vijnanabhikshu's 16th century Yoga-Varttika. The second chapter of the Yoga-sutra contains the core of Patanjali's philosophical and metapsychological framework, and it also defines both the components of kriya-yoga and the first five components of the eight limbed Ashtanga-Yoga.