Patañjali’s Ashtanga Yoga – the system from which the Yoga I practice & teach is derived – is a practical philosophy engineered to bring the body and thought energy under progressive control as a means to accomplishing (Sadhana) Self-realisation whereby human consciousness and its manifestations are transcended. Achieving this state is both the system’s ultimate goal and its definition of Yoga:
1/2. Yogaś citta vṛtti nirodhaḥ – The restraint of the modifications of the mind-stuff is Yoga
The system is composed of eight stages, or limbs, as it literally translates (asha = eight, anga= limb) and is subsequently referred to as the ‘eight-limbed’ path. The practice (abhyāsa) of and non-attachment (vairagya) to the limbs facilitates the restraint of the mental modifications. But only when well attended to for a long time, without a break and with full attention.
The system is laid out in the Yoga Sūtras of Patañjali, a treatise of the theory and practice of yoga representing the climax of a long development of yogic technology at the turn of the Common Era. Within 196 sūtras or ‘aphorisms’ (concise statements containing general truths), the Sūtras delineate the entire science of Yoga across four padas (books).
Read more in my book.