Why Do Thoughts Cease When Turning the Light Inward to Observe One's Own Mind?

Question: When I introspect my thoughts, is this awareness that observes thoughts the mind consciousness or the true mind? I now suspect that it might be another mind consciousness of mine observing the thought that arises in the present moment. Why do I have this suspicion? It comes from an experience I have had: when I become aware that a thought arises in the present moment, that thought might originally have been a complete sentence, but the moment I first become aware of it, only half of it pops out and then disappears, cut off by my awareness. So this awareness that I believe cut what should have been a complete sentence into half a sentence—could it be another mental intention? If it is another mental intention that canceled out the previous one, then is my method of introspection—my so-called awareness (as a third party)—wrong? Or is it using the mind consciousness to suppress thoughts?

Answer: The mind that can be aware of thoughts is not the true mind. The true mind does not know any dharma at the level of the worldly realm, including the thoughts of the seven consciousnesses; yet the true mind definitely can know the thoughts and various activities of the seven consciousnesses—it is just that what He knows is not content at the level of worldly dharmas. Let us set this aside for now. Speaking only of the mind that can observe thoughts: on the surface, it is the solitary mental consciousness. The solitary mental consciousness can observe—or one might call it introspect—its own thoughts.

When the mind consciousness introspects its own thoughts, those thoughts are of various kinds. If a thought is evil and unwholesome, the solitary mental consciousness then knows its own thought is bad, and the thought automatically disappears. If it is not like this—if the thought is a wholesome thought related to cultivation, or a thought neither wholesome nor unwholesome—then, due to insufficient meditative concentration, the attention shifts to the observing side of the consciousness, and because mental power on the observed side where the thought arises is insufficient, the thought can no longer arise, and thus it ceases.

If this situation occurs during cultivation, one needs to further strengthen the training in meditative concentration. Only when the power of concentration is sufficient can both the observing and the observed sides of consciousness continue, maintaining balance—that is, the thoughts do not cease, and the observation does not cease either. In this way, one day wisdom will arise: on the one hand, one can discern whether thoughts are wholesome or unwholesome; on the other hand, one can discern the arising, ceasing, changing, and abiding of thoughts, their suffering, emptiness, impermanence, and non-self, and one can also seek out the source from which thoughts arise—the true mind.

In fact, in the introspective activity of the solitary mental consciousness, when the power of concentration is sufficient, there is also the introspection of the manas; that is, the mind consciousness and the manas jointly observe the mind consciousness and the manas. There is both self-observation and cross-observation, mutual observation. Only such observation is ultimate observation, capable of giving rise to genuine power of awareness and wisdom.