Prana constitutes that aspect of Antah-karana which is spoken of as Kriya-sakti, i.e., wherein Isvara manifests Himself in many a form of activity. It corresponds to the dark or back side of a mirror. Manas and Buddhi constitute that aspect of Antah-karana which is here spoken of as Jnana-sakti, wherein Isvara manifests Himself as a self-conscious cogniser. This corresponds to the clear or front side of a mirror. The self-conscious Atman, when associated with the upadhi of prana in activity, by way of lending to it His own existence and light, is spoken of as the doer; and when associated, in the same way, with the Manas and Buddhi which undergo changes of condition, He is said to cognise.

The organ of cognition.

8-9. Like unto a clear mirror, Buddhi, because of the predominance of Sattva in it and in virtue of the reflection of Atman in it receives images of external objects.

The predominance of Sattva is necessary, since otherwise Rajas and Tamas would give rise to covetousness and forgetfulness.

9-10. And so do all the indriyas (senses), because of their connection with the Antahkarana; they are like spokes attached to the felly of a wheel.

That is to say, though by nature the indriyas move towards their respective objects, still their action is limited and controlled by the Buddhi; so that perception or non-perception or misperception of sense-objects through the sense-organs depends, at any given moment, on the state of the antahkarana at the time.

Nadis, the vehicles of the sense-organs.

10-11. There are nadis woven in the antah-karana, like unto threads woven into a net. By them, verily, reaching up to the physical regions of sensation, all sense-organs move, like sparks of fire, towards their respective objects.

Antah-karana is the Linga-Sarira impregnated with Jnana-sakti and Kriya-sakti, i.e., endued with the faculties of cognition and action.

Nadis are tube-like threads of subtle ethereal matter in the body. It is through these Nadis that all the senses, accompanied with the mind in one or another of its forms, pass towards their respective objects in the external world. When passing from the sushupti to the jagrat or waking state of consciousness, these sense-organs pass up to the very physical regions of sensation, such as the eye, the ear, etc.

12. The midmost portion of the body is spoken of as the Muladhara, 'the primary seat'; it is two inches above the anus and two inches below the penis.

13-14. It is triangular, with the apex turned downwards, like a young girl's organ of generation; and there dwells the Para-Sakti, the Supreme force called Kundalini, the mother of Prana, Agni, Bindu, and Nada; she is called Sarasvati.