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

In the process of discerning all dharmas—whether a thought has been stirred or not, whether the thought is obvious or not, whether one is 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 has been discerned, these two consciousnesses definitely exist simultaneously; the difference lies in which one discerns clearly and which one does not, which one discerns obviously and which one does not—it is a matter of which one takes the leading role in discernment. As soon as a thought is stirred, these two consciousnesses certainly appear together at the same time. Because the manas is the dominant condition (adhipati-pratyaya) of the mind consciousness, where there is mind consciousness there must be the 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 manas's discernment and stirring of thought were absent, the mind consciousness would not appear.

Moreover, the manas is an uninterrupted consciousness; it exists at all times, constantly operating, constantly engaging with objects, constantly grasping. 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 such times the manas does have thoughts; it is engaging with objects and deliberating. It is merely that the mind consciousness lacks the wisdom to observe this. Who knows when the manas might make a decision, and then the mind consciousness on its side will no longer be able to settle down and will begin some kind of action or 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 inevitably engage in activity following the manas's intentions.