Why Can the Defiled Manas Only Generate Defiled First Six Consciousnesses?

The first six consciousnesses arise based on the volitional actions (cetanā) of the manas; they manifest according to the needs of the manas. Whatever the manas requires, the six consciousnesses arise to perform accordingly. Therefore, if the manas is defiled, the six consciousnesses will consequently engage in defiled karmic actions. If the manas is pure, the six consciousnesses will consequently engage in pure karmic actions. According to the fundamental cause of sentient beings' cyclic existence in birth and death, as elucidated by the twelve links of dependent origination, it is because the manas possesses ignorance (avidyā). With ignorance as the condition, the ignorant volitional actions of the manas arise. With the ignorant volitional actions of the manas as the condition, the ignorant bodily, verbal, and mental actions of the six consciousnesses arise. All bodily, verbal, and mental actions are stored as seeds within the ālaya-vijñāna.

The volitional actions of the manas refer to its decisive choices. After the manas makes a choice, the six consciousnesses arise to assist the manas in its actions. Therefore, if the manas is defiled and possesses ignorance, the six consciousnesses, acting as assistants, must aid the manas in performing defiled karmic actions. However, even if the manas is defiled, when it does not choose defiled actions, the mental consciousness (mano-vijñāna) can rely on its own purity to influence the manas. If the manas permits the pure actions of the mental consciousness, then pure karmic actions will arise. Therefore, the practice of cultivation involves steeping oneself in wholesome dharmas and using these wholesome dharmas to influence the manas. By doing so, the ignorance of the manas is eradicated, and the manas is transformed. When the mind becomes pure, one will attain pure karmic fruits to enjoy in the future.