This is the first comprehensive and systematic analytical study of the major philosophical concepts of classical yoga. The book consists of a series of detailed discussions of the key concepts used by Pata-jali in his Yoga-Sutra to describe and explain the enigma of human existence and to point a way beyond the perpetual motion of the wheel of becoming. Feuerstein's study differs from previous ones in that it seeks to free Pata-jali's aphoristic statements from the accretions of later interpretations; instead, the author places the Sutra in its original context and sees it as the source of the whole edifice of classical yoga and not just as a summary of previous developments. This book will be of interest to comparative reliogionists, Indologists, and practitioners of yoga who wish to deepen their understanding of its philosophical basis.