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. V. The nirodha or restrained mind is that in which all mental states are arrested. This leads to kaivalya. Ordinarily our minds are engaged only in perception, inference, etc.—those mental states which we all naturally possess. These ordinary mental states are full of rajas and tamas. When these are arrested, the mind flows with an abundance of sattva in the saṃprajñāta samādhi; lastly when even the saṃprajñāta state is arrested, all possible states become arrested. Another important fact which must be noted is the relation of the actual states of mind called the vṛttis with the latent states called the saṃskāras—the potency. When a particular mental state passes away into another, it is not altogether lost, but is preserved in the mind in a latent form as a saṃskāra, which is always trying to manifest itself in actuality. The vṛttis or actual states are thus both generating the saṃskāras and are also always tending to manifest themselves and actually generating similar vṛttis or actual states. There is a circulation from vṛttis to saṃskāras and from them again to vṛttis (_saṃskārāḥ vṛttibhiḥ kriyante, saṃskāraiśca vṛttayaḥ evaṃ vṛttisaṃskāracakramaniśamāvarttate_). So the formation of saṃskāras and their conservation are gradually being strengthened by the habit of similar vṛttis or actual states, and their continuity is again guaranteed by the strength and continuity of these saṃskāras. The saṃskāras are like roots striking deep into the soil and growing with the growth of the plant above, but even when the plant above the soil is destroyed, the roots remain undisturbed and may again shoot forth as plants whenever they obtain a favourable season. Thus it is not enough for a Yogin to arrest any particular class of mental states; he must attain such a habit of restraint that the saṃskāra thus generated is able to overcome, weaken and destroy the saṃskāra of those actual states which he has arrested by his contemplation. Unless restrained by such a habit, the saṃskāra of cessation (_nirodhaja saṃskāra_) which is opposed to the previously acquired mental states become powerful and destroy the latter, these are sure to shoot forth again in favourable season into their corresponding actual states.