Yoga Sutras

the writings of Patanjali which set down most of what he had studied throughout India under the name of "yoga." An excellent treatise on the subject and an early example of both structural and functional analysis. In the second verse of his treatise, Patanjali gives this often-quoted definition of Yoga: Yogash chitta vritti nirodhah Yoga is the cessation of the modifications of the substance of the mind.