This kāraṇacitta contracts or expands and appears as our individual cittas in our various bodies at successive rebirths. The kāraṇacitta is always connected with the purusha and appears contracted when the purusha presides over animal bodies, and as relatively expanded when he presides over human bodies, and more expanded when he presides over the bodies of gods, etc. This contracted or expanded citta appears as our kāryyacitta which always manifests itself as our states of consciousness. After death the kāraṇacitta, which is always connected with the purusha, manifests itself in the new body which is formed by the āpūra (filling in of prakṛti on account of effective merit or demerit that the purusha had apparently acquired). The formation of the body as well as the contraction or expansion of the kāraṇacitta as the corresponding kāryyacitta to suit it is due to this āpūra. The Yoga does not hold that the citta has got a separate fine astral body within which it may remain encased and be transferred along with it to another body on rebirth. The citta being all-pervading, it appears both to contract or expand to suit the particular body destined for it owing to its merit or demerit, but there is no separate astral body (Tattvavaiśāradī, IV. 10). In reality the karaṇacitta as such always remains vibhu or all-pervading; it is only its kāryyacitta or vṛtti that appears in a contracted or expanded form, according to the particular body which it may be said to occupy.
The Sāṃkhya view, however, does not regard the citta to be essentially all-pervading, but small or great according as the body it has to occupy. Thus Bhikshu and Nāgeśa in explaining the Bhāshya, “others think that the citta expands or contracts according as it is in a bigger or smaller body, just as light rays do according as they are placed in the jug or in a room,” attributes this view to the Sāṃkhya (Vyāsabhāshya, IV. 10, and the commentaries by Bhikshu and Nāgeśa on it).[[39]]
It is this citta which appears as the particular states of consciousness in which both the knower and the known are reflected, and it comprehends them both in one state of consciousness. It must, however, be remembered that this citta is essentially a modification of prakṛti, and as such is non-intelligent; but by the seeming reflection of the purusha it appears as the knower knowing a certain object, and we therefore see that in the states themselves are comprehended both the knower and the known. This citta is not, however, a separate tattva, but is the sum or unity of the eleven senses and the ego and also of the five prāṇas or biomotor forces (Nāgeśa, IV. 10). It thus stands for all that is psychical in man: his states of consciousness including the living principle in man represented by the activity of the five prāṇas.
It is the object of Yoga gradually to restrain the citta from its various states and thus cause it to turn back to its original cause, the kāraṇacitta, which is all-pervading. The modifications of the kāraṇacitta into such states as the kāryyacitta is due to its being overcome by its inherent tamas and rajas; so when the transformations of the citta into the passing states are arrested by concentration, there takes place a backward movement and the all-pervading state of the citta being restored to itself and all tamas being overcome, the Yogin acquires omniscience, and finally when this citta becomes as pure as the form of purusha itself, the purusha becomes conscious of himself and is liberated from the bonds of prakṛti.
The Yoga philosophy in the first chapter describes the Yoga for him whose mind is inclined towards trance-cognition. In the second chapter is described the means by which one with an ordinary worldly mind (vyutthāna citta) may also acquire Yoga. In the third chapter are described those phenomena which strengthen the faith of the Yogin on the means of attaining Yoga described in the second chapter. In the fourth chapter is described kaivalya, absolute independence or oneness, which is the end of all the Yoga practices.
The Bhāshya describes the five classes of cittas and comments upon their fitness for the Yoga leading to kaivalya. Those are I. kshipta (wandering), II. mūḍha (forgetful), III. vikshipta (occasionally steady), IV. ekāgra (one-pointed), niruddha (restrained).
I. The kshiptacitta is characterised as wandering, because it is being always moved by the rajas. This is that citta which is always moved to and fro by the rise of passions, the excess of which may indeed for the time overpower the mind and thus generate a temporary concentration, but it has nothing to do with the contemplative concentration required for attaining absolute independence. The man moved by rajas, far from attaining any mastery of himself, is rather a slave to his own passions and is always being moved to and fro and shaken by them (see Siddhānta-candrikā, I. 2, Bhojavṛtti, I. 2).
II. The mūḍhacitta is that which is overpowered by tamas, or passions, like that of anger, etc., by which it loses its senses and always chooses the wrong course. Svāmin Hariharāraṇya suggests a beautiful example of such concentration as similar to that of certain snakes which become completely absorbed in the prey upon which they are about to pounce.
III. The vikshiptacitta, or distracted or occasionally steady citta, is that mind which rationally avoids the painful actions and chooses the pleasurable ones. Now none of these three kinds of mind can hope to attain that contemplative concentration called Yoga. This last type of mind represents ordinary people, who sometimes tend towards good but relapse back to evil.
IV. The one-pointed (ekāgra) is that kind of mind in which true knowledge of the nature of reality is present and the afflictions due to nescience or false knowledge are thus attenuated and the mind better adapted to attain the nirodha or restrained state. All these come under the saṃprajñāta (concentration on an object of knowledge) type.