The Study of Dharma Requires Consciousness to Investigate Jointly with Manas in Samadhi

Regardless of how much the Dharma the conscious mind (mano-vijñāna) may know, if the root consciousness (manas) remains unaware, doubt will arise, and the mind will not feel settled or grounded. To resolve the doubts of the root consciousness and prevent it from doubting again, the conscious mind should not grasp things alone. Instead, both consciousnesses should investigate together. Upon direct experiential realization, both consciousnesses will know, leaving no room for doubt. To eradicate doubt and give rise to faith, it is necessary not only to eliminate the doubt of the conscious mind but, more importantly, to eliminate the doubt of the root consciousness.

Therefore, when studying the Dharma, the conscious mind should refrain from mere speculation. Instead, it should engage in joint investigation with the root consciousness within meditative concentration (dhyāna). The doubt of the conscious mind is superficial, while the doubt of the root consciousness is profound. The deeper the doubt, the greater the sense of release upon its resolution, the greater the wisdom gained, and the more profound the transformation of body and mind.