To define Yoga it is useful to combine etymology, history and philosophy. The word Yoga has several translation. It is derived from Sanskrit root yuj. A popular translation of the word yoga is union; union of body, mind and consciousness (Iyengar, 2001). Other interpretations of the word yoga are “to tie the strands of the mind together”, “to be one with the divine”. A translation of the word yoga that I particularly like is “to attain what was previously unattainable”. According to Desikachar, each time we reach a point where we have never been before, each of these movements and changes is yoga. It can be a new opening in the body or a new understanding in the mind.

In the West, we have a multitude of competing philosophical and religious systems. Similarly, there are many systems of Hindu philosophy that are metaphysically distinct. Yoga is one of the six systems [1] that recognize the authority of the Veda[2] and the Upanishads[3]. They are collectively known as darsana which means “see” “view” or “point of view”. In Hinduism, Yoga is a philosophy, a system of self-realization, a means to spiritual enlightenment. Yoga aligns closely with a prior school of thought called Samkhya, with both systems sharing a dualist cosmology; for both the cosmos is composed of two categories Prakrti (Nature) and Purusha (pure consciousness).

The Bhagavad Gita is major philosophical text of Hinduism, a famous chapter in the Mahabharata, a colossal collection of stories compiled between 400 BCE and 200 CE. The story recounts a conversation on a battle field between the gods Krishna and Arjuna. Throughout this conversation Krishna introduces two alternative forms of spirituality, the contemplative and the active. The prior is associated with asceticism or the renunciation of a social and worldly life. The Gita argues against this misconception. By taking the doctrine of nivritti, (negation), a very popular tenant in ancient India, and augmenting it with positive spiritual action Krishna teaches Arjuna not so much about renunciation of action, but about renunciation in action. The Bhagavad Gita emphasis that our inner quest, our search, should not be a flight from life.

There are many systems or schools of Yoga[4]. These schools share similar but sometimes contradictory ideas. When we talk about yoga, we talk about a multitude of visions and orientations with sometimes conflicting theoretical foundations (Feuerstein, 2008). This is probably because yoga was developed by many different people with different philosophical, religious and political agenda, writing in very different epochs of history.

Patanjali’s school of thought is recognized by traditional Vedic schools as the authoritative source of Yoga. His book Yogasūtrat (complied prior to 400 CE) is often referred as the most significant work on yoga. Yoga is defined by Patanjali as the cessation of movements or fluctuations in consciousness « yoga citta vrtti nirodhah » (Yogasūtrat I.2). The work of Patanjali focuses on the mind, what its qualities are and how to control it. According to the Yogasūtrat of Patanjali, it is through the discipline of consciousness, the control of the fluctuations (vrtti) of the mind, that beings achieve peace and eventually liberation (moksha).

In the late nineteenth and twentieth century, influential Indian religious leaders Svami Viveknanda (1863–1902) and Svami Sivananda (1887-1963) developed systems of Yoga based on Patanjali’s[5] Ashtangayoga[6] and called them Raja Yoga. These sages promoted Patanjali’s text Yogasūtrat as the most authoritative source on Raja Yoga (Brich, 2014). It is generally accepted that Raja Yoga refers to types of Yoga which are based more on meditation while Hatha Yoga is associated with physical techniques such as postures (asana) (Brich, 2014). Svami Viveknanda and Svami Sivananda were both influential figures in bringing yoga to the West. The identification of Patanjali with Raja Yoga is relatively recent and has been popularized by Svami Vivekananda’s book Raja Yoga (1896). The pervasiveness of “Patanjali’s Rajayoga” in both popular publications on Yoga and more scholarly ones reflects the influence of Svami Vivekananda’s books on modern Yoga in India and internationally (Brich, 2014).

In his system of Yoga, Svami Vivekananda dismisses posture (asana), claiming that Raja Yoga has little to do with Hatha Yoga. He separates Raja from Hatha Yoga and advocated the independence and superiority of the former over the latter. In his view, Hatha Yoga is merely concern with making the physical body strong which is not necessary to achieve spiritual enlightenment. Svami Vivekananda’s Raja Yoga states: “We have nothing to do with Hathayoga here, because its practices are very difficult, and cannot be learned in a day, and, after all, do not lead to any spiritual growth” (Svami Vivekananda in Brich 2014). Conversely, Svami Sivananda recognises that Raja and Hatha Yoga as two different practices, but believes that both are necessary to attain liberation as he believes that physical techniques assist in the control of the mind “Hatha Yoga concerns with the physical body and control of breath. Raja Yoga deals with the mind. Raja Yoga and Hatha Yoga are interdependent. Raja Yoga and Hatha Yoga are the necessary counterparts of each other. No one can become a perfect Yogi without knowledge of the practice of both the Yogas. Raja Yoga begins where properly practised Hatha Yoga ends.” (Svami Sivananda in Brich 2014)

What may be confusing it that the term Raja Yoga, although associated with Patanjali in part thanks to Svami Vivekananda and Svami Sivananda, did not derived from Patanjali. It was not until the 16^th century that the word appeared in a commentary of the Yogasutrat. According to Brich’s research, the earliest definition of Raja Yoga is found in the 12th century, in a Yoga text called Amanaska, which proclaimed Rajayoga to be superior to all other Yogas. Raja Yogameans literally “king-yoga” which implies superiority over other Yoga systems including Hatha yoga. From the twelfth to the fifteenth centuries, the word Raja Yoga was used as a synonym for Samadhi, yet after the sixteenth century, textual evidence show reinterpretation of the word and attempts to connect it with different systems of Yoga.

The yogic sage Svatmarama dismantled the previously existing hierarchy and rivalries between Raja and Hatha Yoga. In his influential book Hatha Yoga Pradipika (15th century CE), Svatmarama merges previous Hatha and Rajayoga systems by asserting that both are dependent upon one another. He created a complete system of Yoga and called it HathaYoga in which the practice of Haṭhayoga leads to the state of Rājayoga (Brich 2011). Svatmarama makes it clear that without the practice of Haṭhayoga, Rājayoga is unattainable, and without the attainment of Rājayoga, Haṭhayoga remains fruitless. “Without Hatha, Rajayoga does not succeed, and without Raja, nor does Hatha Yoga. Therefore, the [yogin] should practice both until the [fourth and final stage of Yoga called] Nispatti [is attained]” (Hathapradipika 2.76). That said, rivalries continued to exists amongst the various school of Yogas even after Svatmarama’s dismantlement of existing competition between Raja and Hatha Yoga in 15^th century Hatha Yoga Pradipika.

Modern styles of yoga as we know it in the West belong to the Hatha Yoga system. Yoga in the West is recognized primarily for the physical aspect of postures or asanas (Salmon 2009; Singleton, 2010). Postures have never been the most important element of traditional Indian practice. Singleton argues that the primacy of postures in yoga is a new phenomenon that has no precedent. It was only around the middle of the 20th century that the physical aspect of yoga became popular in India thanks to T. Krishnamacharya (1888-1989); known as the father of modern yoga. According to Singleton’s research, T. Krishnamacharya’s teaching drew heavily on Indian gymnastics. Three disciples of T. Krishnamacharya, B.K.S. Iyengar, Sri K. Pattabhi Jois and T.K.V. Desikachar, popularized the physical aspect of yoga in the mid-1990s (Singleton, 2010).  B.K.S. Iyengar and Sri K. Pattabhi Jois, developed styles of yoga of which most other modern styles derive; Iyengar Yoga and Ashtanga Vinyasa Method.