Discourse on the Sutra of the Father and Son Compendium (174)

The sixth and seventh consciousnesses transform in the causal ground; the first five and eighth consciousnesses are perfected in the fruition ground.

Among the five aggregates, the consciousnesses we use most are the sixth and seventh. The sixth consciousness encompasses all kinds of thoughts, views, feelings, sensations, and discriminations. For instance, the mind listening to the Dharma here is the sixth consciousness. The content of the Dharma teaching becomes the object of mental consciousness (dharma-dhātu). When the mental faculty (manas) comes into contact with this dharma-dhātu, the ālaya-vijñāna gives rise to the sixth consciousness. This sixth consciousness contemplates and analyzes what is heard, giving rise to discernment, observation, and feelings of understanding or non-understanding regarding the Dharma. Sentient beings primarily function through the sixth and seventh consciousnesses during their lives. The first five consciousnesses are secondary; they do not involve such numerous and complex mental activities. They are simply the coarse acts of seeing, hearing, smelling, tasting, and touching, while the subtle discrimination, feelings, and thoughts are mainly handled by the sixth consciousness. The mental faculty (manas) is the governing consciousness; without the manas, there is no sixth consciousness. Our activities involving the five aggregates are primarily governed by these two consciousnesses. Cultivation primarily focuses on transforming these two consciousnesses. When these two consciousnesses are thoroughly transformed, the first five consciousnesses change accordingly, and the functions of the eighth consciousness can then be fully realized. At that point, we attain Buddhahood.

Therefore, in our cultivation, are we cultivating the true mind or the deluded mind? The true mind does not require cultivation. When the ignorance of the deluded mind is completely severed and afflictions are fully eradicated, the true mind returns to its original state. When we cleanse the seeds of unwholesome karma from the true mind, the true mind restores its original nature, and we become a Buddha. We are not yet Buddhas now because the ālaya-vijñāna still contains the ignorance and defiled karma of the seven consciousnesses. Attaining Buddhahood requires the elimination of countless layers of ignorance. Understanding and realizing one truth eliminates one layer of ignorance. When ignorance is completely eliminated, the path to Buddhahood is perfectly accomplished. This is the way of cultivation.