I. Yama (restraint). These yama restraints are: abstinence from injury (ahiṃsā); veracity; abstinence from theft; continence; abstinence from avarice.
II. Niyama (observances). These observances are cleanliness, contentment, purificatory action, study and the making of God the motive of all action.
III. Āsanas (posture). Steady posture and easy position are regarded as an aid to breath control.
IV. Regulation of breath (prāṇāyāma) is the stoppage of the inspiratory and expiratory movements (of breath) which may be practised when steadiness of posture has been secured.
V. Pratyāhāra (abstraction). With the control of the mind all the senses become controlled and the senses imitate as it were the vacant state of the mind. Abstraction is that by which the senses do not come in contact with their objects and follow as it were the nature of the mind.
VI. Dhāraṇā (concentration). Concentration is the steadfastness of the mind applied to a particular object.
VII. Dhyāna (mediation). The continuation there of the mental effort by continually repeating the object is meditation (dhyāna).
VIII. Samādhi (trance contemplation). The same as above when shining with the light of the object alone, and devoid as it were of itself, is trance. In this state the mind becomes one with its object and there is no difference between the knower and the known.
These are the eight yogāṅgas which a Yogin must adopt for his higher realisation. Of these again we see that some have the mental side more predominant, while others are mostly to be actualised in exterior action. Dhāraṇā, dhyāna and samādhi, which are purely of the samprajñāta type, and also the prāṇāyāma and pratyāhāra, which are accessories to them, serve to cleanse the mind of impurities and make it steady, and can therefore be assimilated with the parikarmas mentioned in Book I. Sūtras 34–39. These samādhis of the samprajñāta type, of course, only serve to steady the mind and to assist attaining discriminative knowledge.
In this connection, it will be well to mention the remaining aids for cleansing the mind as mentioned in Yoga-sūtra I., viz. the cultivation of the habits of friendliness, compassion, complacency and indifference towards happiness, misery, virtue and vice.