Yoga is one of the six orthodox systems of Indian philosophy, originally collated by Patanjali in the Yoga Sutras (around 200 AD).
In the Bhagavad Gita, the most important authority on yoga philosophy, Sri Krishna explains to Arjuna that yoga means a deliverance from contact with pain and sorrow.
The Kathopanishad describes yoga: 'When the senses are stilled, when the mind is at rest, when the intellect wavers not - then, say the wise, is reached the highest stage. This steady control of the senses and mind has been defined as yoga.'
The Yoga Sutras describe yoga as the restraint (nirodhah) of the fluctuations (vrtti) of consciousness (chitta), where consciousness or the complete mind is made up of mind, reason and ego. Thus yoga is the method by which the restless mind is calmed and the energy directed into constructive channels.
The stages of yoga, or the eight limbs, is one pathway (Raja Yoga or Yoga Marga). By profound meditation, the knower, the knowledge and the known become one; or the seer, the sight and the seen; or the musician, the instrument and the music. Other paths (margas) are Karma (actions), Bhakti (devotion), and Jnana (knowledge).
Patanjali lists five classes ofchitta vrtti that create pleasure and pain:
He lists five that create pain:
He also offered asanas, pranayama, and the eightfold path.
The Mundakopanisad describes OM, the syllable aum, as the bow, the Self as an arrow, and Brahman as the target. The undistracted man makes them one.