The Difference between Deliberation of the Manas and Thinking of the Mind Consciousness

Question: I seem to understand how to use the manas to deliberate; it is a mental activity that cannot be done by thinking—once you think, the mind consciousness gets involved, and once the mind consciousness is involved, that state becomes less deep and subtle. Is this correct? This state lasts only a very short time; when the deliberation reaches a point where the problem gets stuck, I use the mind consciousness to think, and immediately the state is no longer so deep and subtle.  

Also, when sitting in meditation, once I apply initial application and sustained examination (vitarka-vicāra) to the state of the body, there arises a feeling that this material body does not exist—there is only a body constituted of slight sensations and the mind consciousness, very unreal. Suddenly a thought arises: the things one normally sees are merely images, pictures, something manifested. With this kind of feeling, after emerging from meditation and looking around, everything still seems so real.  

Answer: You can now probably distinguish whether, during meditation, it is the mind consciousness that is thinking or the manas that is deliberating, and the method you are using is also correct; it is just that your skill is not yet proficient and effortless, so you need to take it slowly and gradually deepen your foundation. When contemplating the Dharma in stillness, it is indeed the case that when using the manas, the mind is very deep and subtle, whereas when using the mind consciousness, it is somewhat superficial, as if separated by a layer—not quite penetrating.  

When observing the material body with fairly strong focus during meditation, meditative concentration (samādhi) will improve; as the concentration deepens, the initial application and sustained examination instead become slight, and the perception of the material body disappears—the mind becomes empty. Meditative concentration can make the mind fine, dense, and precise; one can often observe things that normally cannot be observed, and can discover the truth of things, thereby penetrating and fully realizing the truth. So when, in concentration, you look at certain things and feel as if they are like images, no longer so real, this is a very good cognition. Maintain it and go deeper still, and you will be even more able to see through the extreme illusoriness and unreality of all kinds of principles and affairs; when the causes, conditions, and season are complete, it is possible to realize emptiness (śūnyatā). Therefore, the realization of all dharmas is realized within profound meditative concentration (dhyāna); even during activities, there is meditative concentration, and this concentration derives from the meditative skill of sitting meditation—it is the extension and continuation of concentration in stillness.