These klishṭa and aklishṭa modifications are of five descriptions: pramāṇa (real cognition), viparyyaya (unreal cognition), vikalpa (logical abstraction and imagination), nidrā (sleep), smṛti (memory). These vṛttis or states, however, must be distinguished from the six kinds of mental activity mentioned in _Vyāsa-bhāshya_, II. 18: grahaṇa (reception or presentative ideation), dhāraṇa (retention), ūha (assimilation), apoha (differentiation), tattvajñāna (right knowledge), abhiniveśa (decision and determination), of which these states are the products. We have seen that from avidyā spring all the kleśas or afflictions, which are therefore seen to be the source of the klishṭa vṛttis as well. Abhyāsa and vairāgya—the aklishṭa vṛttis, which spring from precepts, etc., lead to right knowledge, and as such are antagonistic to the modification of the guṇas on the avidyā side. We know also that both these sets of vṛttis—the klishṭa and the aklishṭa—produce their own kinds of saṃskāras, the klishṭa saṃskāra and the aklishṭa or prajñā saṃskāra. All these modifications of citta as vṛtti and saṃskāra are the dharmas of citta, considered as the dharmin or substance. CHAPTER IX THE THEORY OF KARMA The vṛttis are called the mānasa karmas (mental work) as different from the bāhya karmas (external work) achieved in the exterior world by the five motor or active senses. These may be divided into four classes: (1) kṛshṇa (black), (2) śukla (white), (3) śuklakṛshṇa (white and black), (4) aśuklākṛshṇa (neither white nor black). (1) The kṛshṇa karmas are those committed by the wicked and, as such, are wicked actions called also adharma (demerit). These are of two kinds, viz. bāhya and mānasa, the former being of the nature of speaking ill of others, stealing others’ property, etc., and the latter of the nature of such states as are opposed to śraddhā, vīrya, etc., which are called the śukla karma. (2) The śukla karmas are virtuous or meritorious deeds. These can only occur in the form of mental states, and as such can take place only in the mānasa karma. These are śraddhā (faith), vīrya (strength), smṛti (meditation), samādhi (absorption), and prajñā (wisdom), which are infinitely superior to actions achieved in the external world by the motor or active senses. The śukla karma belongs to those who resort to study and meditation. (3) The śuklakṛshṇa karma are the actions achieved in the external world by the motor or active senses. These are called white and black, because actions achieved in the external world, however good (śukla) they might be, cannot be altogether devoid of wickedness (kṛshṇa), since all external actions entail some harm to other living beings. Even the Vedic duties, though meritorious, are associated with sins, for they entail the sacrificing of animals.[40]