The mind consciousness and the manas simultaneously discern and give rise to thoughts

In the process of discerning all dharmas—whether a thought is stirred or not stirred, whether the thought is obvious or not, whether in the state of initial application (vitarka) or in the state of 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 which one discerns clearly and which one discerns unclearly, which one discerns obviously and which one discerns unobviously—it is a matter of which one takes the lead in discerning. As soon as a thought is stirred, these two consciousnesses certainly appear together. Because the manas is the dominant condition (āśraya) 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 is active, the manas must already have been active. If the discernment and thought-activity of the manas were lacking, the mind consciousness would not appear.

Moreover, the manas is an uninterrupted consciousness, existing at all times, constantly operating, constantly grasping at objects, constantly clinging. There is never a moment when it is not stirring thoughts, never a moment when it is not deliberating. 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 is able to detect its existence and its mental activity.

Many people, when their mind consciousness is not stirring thoughts and they cannot observe the manas, feel that they are quite tranquil at the moment, without any thoughts. In fact, at this time the manas does have thoughts; it does have grasping and deliberation (manana). 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 settle down 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 the manas is about to engage in some activity, the mind consciousness cannot remain tranquil and will follow the manas's intentions to act.