The Yoga Sutras were formulated in India in the third century B. C. The word yoga is from the Sanskrit root meaning "join" or "unity, " and a sutra is a thread or aphoristic verse. Yoga itself is not associated with any particular religion; it simply offers techniques leading to the direct experience of truth. The basic questions Who am I? Where am I going? What is the purpose of life? are asked by every generation, and Patanjali's answers form one of the world's oldest and most vibrant spiritual texts. He explains what yoga is, how it works, and exactly how to purify the mind and let it settle into absolute stillness. Alistair Shearer's extensive and helpful introduction and superb translation, fully preserving Patanjali's jewel-like style, bring these ancient but vital teachings to those who seek the path of self-knowledge today.