Hatha is a sanskrit name consisting of two parts “Ha” and “Tha”. Ha (or Ham is the sound of Pingala Nadi, prana, chi, vital life force) where as Tha (or Tham, Ksham is the sound of Ida Nadi, mind, mental force). Yoga means Union, therefore the meaning of Hatha-Yoga may be interpreted as Yoga through the union of prana and mind.
The Human body is like a vehicle or temple which houses the mind and spirit. The ancient Sages of Yoga realised through their expanded awareness, inner vision and intuition which was developed through the awakening of the Kundalini that the human body contained many interesting mysteries.
Some yogis who were undergoing an inner awakening “ either in their Central Nervous System or the Pranic system, or both” unconsciously developed bodily movements known as Kriyas and assumed classical Yoga postures. Also some even began breathing in peculiar and not previously known ways. Yogic Adepts like Paramahamsa Satyananda Saraswati and others believe that these Kriyas that are a phenomena are initiated as a result of natural evolution “biological, Psychic, Spiritual” and heralds the last evolutionary step as a homosapien human being.
Ancient Yogis also had a close affinity with nature and the environment around them, including the earth, space, stars and the sun to name just a few. They also started to study animals with great depth, and the subsequent naming of many asanas after animals is a fitting tribute to the ancient Yogis great affinity with nature. This was probably the starting point which was later expanded on through SELF experimentation over centuries and millennia to encompass all of the Classical asanas and pranayamas that we know today.
Mind and prana in yogic terminology can be understood as Ida and Pingala Nadis. Their purification and balance results in an awakening which when sustained perfectly for long periods of time leads to an awakening of Ajna Chakra, which triggers an awakening of Mooladhara Chakra. At this time if all conditions are auspicious Sushumna Nadi opens and Kundalini makes her ascent through all the major Chakras illumining them fully, as she passes along inside the Brahma Nadi of Sushumna (the spinal cord). This Shakti force conquers the mind at Ajna Chakra.
Dhyana (Meditation) rapidly ensues as Shiva (higher consciousness) descends to meet Shakti (Individual consciousness). Their meeting removes the duality and once more they unite in samadhi at Sahasrara and realize the ecstasy of divinity that we are truly meant to experience (the real purpose of evolution). This, to put it briefly is the theory and philosophy of Hatha-Yoga and Tantra in general. But to get to this lofty realization first it is said by the masters of Kundalini Yoga that we must take to Hatha-Yoga and utilize the six classical Hatha yoga shatkarmas.
Classically shatkarmas are practiced whilst one is mastering Asanas, or after reaching some degree of perfection in Asanas, but before Pranayama (always), Mudra, Bandha and Kriya Yoga.
Hatha yoga deals with conquering and transcending the limitations of the mind, and experiencing meditation through prana. Instead of going through the front door and trying to control or tackle the mind directly, these yogis who systematized Hatha-Yoga knew that the key to transcendence lied in Prana and Kundalini. Their route was the backdoor via the elevator of Sushumna. The undeniable goal of Samadhi that Rishi Patanjali expounds in the Yoga Sutras can be reached by Kundalini Shakti awakening directly.
Hatha-Yoga Pradipika, which is one of the most respected authentic texts on Hatha-Yoga, is divided into four chapters leading to the goal of life- Samadhi. A brief summary of this famous Yogic Text follows.
First Chapter: It deals with perfecting various asanas and explains the signs and symptoms of perfection in asana.
Second Chapter: It deals with Shatkatma and Pranayama. The six shatkarmas are essential before attempting advanced Pranayama techniques. They are neti, basti, dhauti, kapalbhati, trataka and nauli. These six shatkarmas are a complete yoga in themselves and are indispensable for any sadhaka (sincere yoga aspirant) contemplating the awakening of Kundalini. Kundalini is a purifying force in itself but the body, pranas and mind must be purified and harmonized first to have the ability to sustain the force of awakening. After shatkarmas have been performed the body is fit for Pranayama. Prana Nigraha (The various breathing techniques of Yoga) first of all deals with the techniques of manipulating and strengthening the breath and prana. Until one arrives at the stage of Kevala Kumbhaka real Pranayama and expansion of prana has not yet been achieved. When Kevala kumbhaka arrives the Kundalini can ascend.
Third Chapter: It delas with Mudra and Bandha and describes the practices needed to raise the Kundalini and open all the Chakras, but the most important sutras describe seeking instruction from a guru or master who is an adept or expert in Kundalini Yoga. Not just in theory but they must have the ability to perceive and guide the aspirant through the unchartered waters of mind and consciousness. Mudras and Bandhas are the keys given to a deserving disciple by their guru and it is said in v128 and v129 that “the ten Mudras told by Adinath Shiva brings perfection, and one who instructs Mudra in the tradition of guru is like Ishwara.
Fourth Chapter: It deals as how the culmination is reached through concentration of nada (sound vibrations of consciousness). After Sushumna Nadi (the nucleus of our being) awakens, and the Kundalini has arisen within the Sushumna, the concentration becomes intense and awareness spontaneous focuses on the many inner sounds that begin to manifest. Many visions and experiences confront the sadhaka in this region, and nada (inner sound) carries the aspirant through the experience of Laya (absorption) to Nirvikalpa Samadhi. This is said to be the culmination of human experience and the true purpose of our existence. Yogis that have reached this far like Paramahamsa Satyananda say that this level of Samadhi is the doorway into another realm of total experience. This system and philosophy of Hatha-Yoga have their origin in the ancient teachings of Tantra the “Tantra Shastras”, which are the ancient teachings of yoga. The original guru of this lineage was Shiva. Shiva first imparted the techniques of yoga to Parvati his wife and disciple. There is reference of these techniques of Hatha yoga in these ancient texts.