Yoga Sutra 1.15 detachment is consciousness of self-mastery
Detachment is consciousness of self-mastery, of one who has no thirst for any object either seen or heard about
Detachment is the consciousness of self-mastery of one who has no thirst for any object either seen or heard about. It is that consciousness in one who is unmoved by visible objects like women, food and drink, or power, who is without thirst for objects heard about such as attainment of heaven or the state of the gods or of those absorbed into prakṛti, is inwardly aware of the defects in them by the power of his meditation, and who is wholly impassive – that consciousness of self-mastery which has nothing to avoid and nothing to accept, is detachment.
To describe detachment (vairāgya) he says, Detachment is the consciousness of self-mastery of one who has no thirst for any object either seen or heard about. The word object has to be taken twice: without thirst for any object seen, and without thirst for any object heard about.
Visible objects means what are both objects and directly perceived. What would they be? He illustrates with the examples of women, food and drink, and power. Though there is an infinity of objects, yet the principal impulse of passion is to possess women, food and drink, and power. In these cases passion is at its most powerful and is to be opposed with corresponding effort. So with objects heard about, which here means those described in the scriptures – the attractions of going to heaven, the joy of being dissolved into prakṛti, or the pleasure of the discarnate state of the gods.
(Opponent) Detachment (vairāgya, without rāga or passion) is simply freedom from thirst, for it will be said (comm. to sūtra II.7), Passion is thirst, is greed.
(Answer) No, for there are four distinct stages in the state of detachment: (1) awareness of striving, (2) awareness of transgressions, (3) awareness of mind alone, and (4) awareness of mastery. The awareness common to these four is detachment. So the commentator says that it is absence of thirst for visible objects or objects heard about, but it is the fourth one, to which the other three are preliminary, which he means, not a detachment which is merely freedom from thirst (perhaps temporary, in the absence of the objects or perhaps without knowledge that they exist).
He explains, he who is inwardly aware of the defects in them – seeing the defects causes detachment from objects, whereas seeing good points in them causes passion;
by the power of his meditation by practising meditation on seeing their defects; who is wholly impassive wholly unresponsive to objects even when right in front of such things, earthly or heavenly. As a crystal does not in fact take the colour of objects beside it, so his mind is in a state free from passion for them.
that consciousness of mastery, consciousness that they can be mastered. It is the state when all that is called desirable is recognized to be capable of being mastered, the state when it is realized that the senses have been mastered, or when the mastery becomes conscious.