According to Wikipedia: "The Yoga SĆ«tras of Patañjali are 196 Indian sĆ«tras (aphorisms) that constitute the foundational text of RÄja Yoga. Yoga is one of the six orthodox Ästika schools of Hindu philosophy, which, according to the Yogatattva Upanishad, is divided into four forms â Mantrayoga, Layayoga, Hathayoga and RÄjayoga â the last of which is the highest (or royal) practice. Although the Yoga Sutras have become the most important text of Yoga, the opinion of most scholars is that Patañjali was not the creator of Yoga, which existed well before him, but merely a great expounder."