Yoga Sutra 2.29 the eight methods
Sūtra II.29
Restraints, observances, posture, restraint of vital currents, dissociation, concentration, meditation, samādhi are the eight methods
(Opponent) But in other yoga scriptures there are only six methods – the ones from posture onwards. They say, ‘The yoga of six methods is now expounded’, and so on. For posture and those which follow it do directly help towards samādhi; not so the restraints and observances.
(Answer) The objection does not hold, because following the restraints and observances is the basic qualification to practise yoga. The qualification is not simply that one wants to do yoga, for the holy text says: ‘But he who has not first turned away from his wickedness, who is not tranquil and subdued, or whose mind is not at rest, he can never obtain the Self (even) by knowledge’ (Kaṭha 1.2.24). And in the Atharva text, ‘It is in those who have tapas and brahmacarya, in whom truth is established’ (Praś. Up. I.15), and in the Gītā, ‘Firm in their vow of brahmacarya’ (VI.14). So the restraints and observances are methods of yoga.
Of the two, restraint is mentioned first to emphasize its supreme importance. For it is everywhere recognized that restraint is of the highest importance. When a yogin is qualified by practising restraint and observance, he can go on to the posture and other steps. Becoming steady in each preceding one, he is able to master the next. But if he has not mounted the previous step, he cannot get on to a higher one.
And it is said elsewhere:
Mastery of a firm sitting posture, or other instructions of yoga, are not, in the case of distracted people; productive of yoga.
Getting rid of the defects, and samādhi – these two will certainly produce it, and nothing else will.
This verse is to emphasize the supreme importance of samādhi and abandonment of all defects; it is not meant to exclude posture and the other methods.
We shall now explain in their due order how each of these yoga methods is practised, and what its nature is.
We shall now explain in their due order how each of these restraints and the other methods is to be practised, and what its nature is, for they cannot be practised without knowing what they are.