Why Are We Unaware That We Are Dreaming When We Dream?

Dreams occur because the manas continuously clings to and becomes attached to certain dharmas, causing the eighth consciousness to accordingly give rise to the dream state. Dreams belong to the realm of appearances manifesting only to the mental consciousness (独影境), where the mental consciousness alone cognizes, without the cooperation of the five sense consciousnesses. Since the conditions for the manifestation of appearances manifesting only to the mental consciousness are relatively few, as long as the manas clings to or dwells upon certain dharmas, these appearances can manifest. Then, when the manas comes into contact with these appearances, the eighth consciousness gives rise to the mental consciousness to cognize them. However, during dreams, the mental consciousness's capacity for thought and judgment is insufficient; its discerning power is relatively weak, and its ability to recognize is not very strong. It is mostly passively led along by the dream state, thus failing to realize that this is a dream. Simultaneously, the mental consciousness's introspective power is also comparatively weak, lacking in wisdom, so it does not know that its own activities are occurring within the dream, that it is cognizing the dream's appearances manifesting only to the mental consciousness. Therefore, it does not know that it itself is in a dream, that it is dreaming.

If an individual is relatively well-cultivated, and their manas has been effectively imbued with the Buddha Dharma and wholesome dharmas, it will not direct the mental consciousness to create unwholesome karma and can control the mental consciousness's actions. Then, for this person in the intermediate state (中阴身), the manas may also be able to control the six consciousnesses so they do not create unwholesome karma, do not manifest karmic actions following unwholesome conditions, and can guide the six consciousnesses to perform good deeds and create wholesome karma. In this way, a wholesome mind accords with the wholesome destinies, making the likelihood of taking rebirth in a wholesome destiny relatively high. Moreover, the mental consciousness also knows how to choose a wholesome destiny, making it possible to take rebirth in a favorable realm.