The Yoga Sutras of Patanjali: The Book of the Spiritual Man by Maharishi Patanjali

The Yoga Sutras of Patanjali, the foundation text of Raja Yoga, one of the six orthodox astika schools of Hindu philosophy. The 196 sutras are divided into four forms – Mantra Yoga, Laya Yoga, Hatha Yoga and Raja Yoga – the last of which is the highest (or royal) practice.