Hatha yoga

Hatha yoga is a branch of yoga that uses physical techniques to try to preserve and channel vital force or energy. The Sanskrit word हठ haṭha literally means "force", alluding to a system of physical techniques. Some hatha yoga style techniques can be traced back at least to the 1st century CE, in texts such as the Hindu Sanskrit epics and Buddhism's Pali canon. The oldest dated text so far found to describe hatha yoga, the 11th-century Amṛtasiddhi, comes from a tantric Buddhist milieu. The oldest texts to use the terminology of hatha are also Vajrayana Buddhist. Hindu hatha yoga texts appear from the 11th century onward.
Some of the early hatha yoga texts describe methods to raise and conserve bindu. This was seen as the physical essence of life that was constantly dripping down from the head and being lost. Two early hatha yoga techniques sought to either physically reverse this process of dripping by using gravity to trap the bindhu in inverted postures like viparītakaraṇī, or force bindu upwards through the central channel by directing the breath flow into the centre channel using mudras.
Almost all hathayogic texts belong to the Nath siddhas, and the important early ones are credited to Matsyendranatha and his disciple, Gorakhnath or Gorakshanath. Early Nāth works teach a yoga based on raising kuṇḍalinī through energy channels and chakras, called Layayoga. However, other early Nāth texts like the Vivekamārtaṇḍa can be seen as co-opting the hatha yoga mudrās. Later Nāth as well as Śākta texts adopt the practices of hatha yoga mudras into a Saiva system, melding them with Layayoga methods, without mentioning bindu. These later texts promote a universalist yoga, available to all, "without the need for priestly intermediaries, ritual paraphernalia or sectarian initiations."
In the 20th century, a development of hatha yoga focusing particularly on asanas became popular throughout the world as a form of physical exercise. This modern form of yoga is now widely known simply as "yoga".

Origins

Earliest textual references

According to the Indologist James Mallinson, some haṭha yoga style techniques practised only by ascetics can be traced back at least to the 1st-century CE, in texts such as the Sanskrit epics and the Pali canon. The Pali canon contains three passages in which the Buddha describes pressing the tongue against the palate for the purposes of controlling hunger or the mind, depending on the passage. However, there is no mention of the tongue being inserted further back into the nasopharynx as in true khecarī mudrā. The Buddha also used a posture where pressure is put on the perineum with the heel, similar to modern postures used to stimulate Kundalini. In the Mahāsaccaka sutta, the Buddha mentions how physical practices such as various meditations on holding one's breath did not help him "attain to greater excellence in noble knowledge and insight which transcends the human condition." After trying these, he then sought another path to enlightenment. The term haṭha yoga was first used in the c. 3rd century Bodhisattvabhūmi, the phrase na haṭhayogena, seemingly meaning only that the bodhisattva would get his qualities "not by force".

Transition from tantric Buddhism to Nāth hatha yoga

Tantric Buddhism

The earliest mentions of haṭha yoga as a specific set of techniques are from some seventeen Vajrayana Buddhist texts, mainly tantric works from the 8th century onwards. In Puṇḍarīka's c. 1030 Vimalaprabhā commentary on the Kālacakratantra, haṭha yoga is for the first time defined within the context of tantric sexual ritual:
While the actual means of practice are not specified, the forcing of the breath into the central channel and the restraining of ejaculation are central features of later haṭha yoga practice texts.
File:Amritasiddhi Witness C Folio IV.jpg|thumb|upright=2|A folio of a medieval copy of the Amṛtasiddhi, written bilingually in Sanskrit and Tibetan
The c. 11th century Amṛtasiddhi is the earliest substantial text describing Haṭha yoga, though it does not use the term; it is a tantric Buddhist work, and makes use of metaphors from alchemy. A manuscript states its date as 1160. The text teaches mahābandha, mahāmudrā, and mahāvedha which involve bodily postures and breath control, as a means to preserve amrta or bindu in the head from dripping down the central channel and being burned by the fire at the perineum. The text also attacks Vajrayana deity yoga as ineffective. According to Mallinson, later manuscripts and editions of this text have obscured or omitted the Buddhist elements. However, the earliest manuscript makes it clear that this text originated in a Vajrayana Buddhist milieu. The inscription at the end of one Amṛtasiddhi manuscript ascribes the text to Mādhavacandra or Avadhūtacandra and is "said to represent the teachings of Virūpākṣa". According to Mallinson, this figure is most likely the Buddhist mahasiddha Virupa.
Another 11th century text, Dispelling the Hindrances of Immortality, is a Tibetan ancillary to the Amṛtasiddhi. Attributed to an Indian, Yogeśvara Amoghavajra, who was living in Tibet, the text describes 108 āsana-like physical movements intended to overcome obstacles to tantric practice.

Early Hindu texts

The c. 10th century Kubjikāmatatantra anticipates haṭha yoga with its description of the raising of Kundalini, and a 6-chakra system.
Around the 11th century, techniques associated with Haṭha yoga also begin to be outlined in a series of early Hindu texts. The aims of these practices were siddhis and mukti.
In India, haṭha yoga is associated in popular tradition with the Yogis of the Natha Sampradaya. Almost all hathayogic texts belong to the Nath siddhas, and the important ones are credited to Gorakhnath or Gorakshanath, the founder of the Nath Hindu monastic movement in India, though those texts post-date him. Goraknath is regarded by the contemporary Nath-tradition as the disciple of Matsyendranath, who is celebrated as a saint in both Hindu and Buddhist tantric and haṭha yoga schools, and regarded by tradition as the founder of the Natha Sampradaya. Early haṭha yoga works include:

The Amaraugha describes three bandhas to lock the vital energy into the body, as in the Amṛtasiddhi, but adding the raising of Kundalinī.
The Dattātreyayogaśāstra, a Vaisnava text probably composed in the 13th century, is the earliest text which provides a systematized form of Haṭha yoga, and the earliest to place its yoga techniques under the name Haṭha. It teaches an eightfold yoga identical with Patañjali's 8 limbs that it attributes to Yajnavalkya and others as well as eight mudras that it says were undertaken by the rishi Kapila and other ṛishis. The Dattātreyayogaśāstra teaches mahāmudrā, mahābandha, khecarīmudrā, jālandharabandha, uḍḍiyāṇabandha, mūlabandha, viparītakaraṇī, vajrolī, amarolī, and sahajolī.
The Vivekamārtaṇḍa, an early Nāth text attributed to Goraknath, contemporaneous with the Dattātreyayogaśāstra, teaches nabhomudrā, mahāmudrā, viparītakaraṇī and the three bandhas. It also teaches six chakras and the raising of Kundalinī by means of "fire yoga".
The Gorakṣaśataka, a Nāth text of the same period, teaches śakticālanīmudrā along with the three bandhas. "Stimulating Sarasvat" is done by wrapping the tongue in a cloth and pulling on it, stimulating the goddess Kundalinī who is said to dwell at the other end of the central channel. This text does not mention the preservation of bindu, but merely says that liberation is achieved by controlling the mind through controlling the breath.
The ̣Śārṅgadharapaddhati, an anthology of verses on a wide range of subjects compiled by Sharngadharain 1363, describes Haṭha yoga including ̣the Dattātreyayogaśāstra's teachings on five mudrās.
The Khecarīvidyā teaches only the method of khecarīmudrā, which is meant to give one access to stores of amrta in the body and to raise Kundalinī via the six chakras.
The Yogabīja teaches the three bandhas and śakticālanīmudrā for the purpose of awakening Kundalinī.
The Śivasamhitā: a 14th or 15th century text. Its first chapter summarizes Śaiva non-dualism and Śrīvidyā Śāktism; the rest of the text describes yoga, the importance of a guru to a student, various asanas and mudras, and the siddhis to be attained with yoga and tantra.

The earliest haṭha yoga methods of the Amṛtasiddhi, Dattātreyayogaśāstra and Vivekamārtaṇḍa are used to raise and conserve bindu which was seen as the physical essence of life that was constantly dripping down from the head and being lost. This vital essence is also sometimes called amrta. These techniques sought to either physically reverse this process or use the breath to force bindu upwards through the central channel.
In contrast to these, early Nāth works like the Gorakṣaśataka and the Yogabīja teach a yoga based on raising Kundalinī. This is not called haṭha yoga in these early texts, but Layayoga. However, other early Nāth texts like the Vivekamārtaṇḍa can be seen as co-opting the mudrās of haṭha yoga meant to preserve bindu. Then, in later Nāth as well as Śākta texts, the adoption of haṭha yoga is more developed, and focused solely on the raising of Kundalinī without mentioning bindu.
Mallinson sees these later texts as promoting a universalist yoga, available to all, without the need to study the metaphysics of Samkhya-yoga or the complex esotericism of Shaiva Tantra. Instead this "democratization of yoga" led to the teaching of these techniques to all people, "without the need for priestly intermediaries, ritual paraphernalia or sectarian initiations."