Is the consciousness with the power of introspection the consciousness accompanied by the five senses or the solitary consciousness?

The power of introspection (pratyavekṣā-bala) is precisely the self-validating cognition (svasaṃvedana), which is one's own validation of oneself and one's own mental factors (caittas). At this time, one's own consciousness and mental factors become the object-aspect (nimitta). This object-aspect has nothing to do with the five sense objects; it is a subjectively imagined realm, and thus has nothing to do with the consciousness accompanied by the five senses (pañca-sahagata-mano-vijñāna); it is the object-aspect corresponding to the solitary consciousness (mano-vijñāna-eka-citta). Therefore, the power of introspection that possesses self-validating cognition belongs to the solitary consciousness, not to the consciousness accompanied by the five senses. The key to distinguishing between these two kinds of consciousness lies in whether the mental sense-objects (dharma-viṣaya) they correspond to are related to the five sense objects: those that are unrelated are subjectively imagined mental sense-objects, which can only be discerned by the solitary consciousness.

When the consciousness accompanied by the five senses appears, the solitary consciousness may also appear; the two kinds of consciousness can appear simultaneously. For example, when seeing a flower, the thoughts, recollections, imaginings, and so on about the flower in the mind all belong to the solitary consciousness; the consciousness accompanied by the five senses is only responsible for jointly discerning the flower before one's eyes together with the five sense consciousnesses, while flowers of the past and future can only be discerned by the solitary consciousness. This past and future includes one minute before and after—in short, anything that is not the present-moment state. For example, when seeing the person opposite, the impressions, thoughts, and so on about this person in the mind all belong to the solitary consciousness. The consciousness accompanied by the five senses has no thoughts or concepts, cannot recall or look forward, and the mental sense-objects it discerns cannot be separated from the realms of the five sense objects.