Mind Consciousness and Manas Simultaneously Discriminate and Initiate Thoughts

In the process of discerning all dharmas—whether a thought arises or not, whether the thought is obvious or not, whether one is in the state of initial application (vitarka) or sustained examination (vicāra)—there is the discernment of the mind consciousness as well as the discernment of the manas. As long as a dharma is discerned, these two consciousnesses definitely exist simultaneously. The difference lies in who discerns clearly and who discerns unclearly, whose discernment is obvious and whose is not obvious—it is a matter of whose discernment takes the lead. As soon as a thought stirs, these two consciousnesses certainly appear together. Because the manas is the mutual dependence (sahāya) of the mind consciousness, where there is mind consciousness there must be manas; the arising of the mind consciousness is the result of the manas's deliberation and selection. Therefore, when the mind consciousness stirs, the manas must have already stirred; if the discernment and thought-activity of the manas were lacking, the mind consciousness would not appear. 

Moreover, the manas is a consciousness without interruption; it exists at all times, constantly running, constantly clinging and grasping, generating thoughts at every moment, deliberating at every moment. The only differences are whether its activity is obvious or not, whether its mental activity is scattered or concentrated, whether it is with attachment or without attachment, and whether the mind consciousness can detect its existence and mental activity. 

When many people's mind consciousness is not generating thoughts and they cannot observe the manas, they feel that they are quite tranquil (praśama) at the moment, with no thoughts. In fact, at this time the manas does have thoughts; it does have clinging and deliberation (manasikāra)—it is merely that the mind consciousness lacks the wisdom to observe it. Who knows when the manas might make a decision, and then the mind consciousness on its side can no longer remain still and will begin to engage in some kind of action and activity. Every action of body, speech, and mind, whether great or small, slight or significant, is the result of the manas's deliberation. When He is about to engage in some activity, the mind consciousness cannot settle into tranquility and will inevitably engage in activity following the manas's intentions.