and philosophical views. It focuses on the study of the Upanishads and the Brahma Sutras (one of its early texts), about gaining spiritual knowledge of Brahman: the unchanging, absolute reality. One of the earliest and most influential sub-traditions of Vedanta is Advaita Vedanta, which posits non-dualistic monism. It emphasizes jñāna yoga (yoga of knowledge), which aims at realizing the identity of one's atman (individual consciousness) with Brahman (the Absolute consciousness).Comans, Michael (2000), The Method of Early Advaita Vedānta: A Study of Gauḍapāda, Śaṅkara, Sureśvara, and Padmapāda, Delhi: Motilal Banarsidass, p. 183. The most influential thinker of this school is Adi Shankara (8th century), who wrote commentaries and other works on jñāna yoga. In Advaita Vedanta, jñāna is attained from scripture, one's guru, and through a process of listening to (and meditating on) teachings. Qualities such as discrimination, renunciation, tranquility, temperance, dispassion, endurance, faith, attention, and a longing for knowledge and freedom are also desirable. Yoga in Advaita is a "meditative exercise of withdrawal from the particular and identification with the universal, leading to contemplation of oneself as the most universal, namely, Consciousness".Yoga Vasistha is an influential Advaita text which uses short stories and anecdotes to illustrate its ideas. Teaching seven stages of yoga practice, it was a major reference for medieval Advaita Vedanta yoga scholars and one of the most popular texts on Hindu yoga before the 12th century. Another text which teaches yoga from an Advaita point of view is the Yoga Yajnavalkya. Tantric yoga According to Samuel, Tantra is a contested concept. Tantra yoga may be described as practices in 9th to 10th century Buddhist and Hindu (Saiva, Shakti) texts which included yogic practices with elaborate deity visualizations using geometric arrays and drawings (mandalas), male and (particularly) female deities, life-stage-related rituals, the use of chakras and mantras, and sexual techniques aimed at aiding one's health, longevity and liberation. Hatha yoga Hatha yoga focuses on physical and mental strength-building exercises and postures described primarily in three Hindu texts:See Burley, page 73. Hatha Yoga Pradipika by Svātmārāma (15th century) Shiva Samhita, author unknown (1500 or late 17th century) Gheranda Samhita by Gheranda (late 17th century) Some scholars include Gorakshanath's 11th-century Goraksha Samhita on the list, since Gorakshanath is considered responsible for popularizing present-day hatha yoga.Bajpai writes on page 524: "Nobody can dispute about the top ranking position of Sage Gorakshanath in the philosophy of Yoga." Vajrayana Buddhism, founded by the