Why Can the Defiled Manas Only Give Rise to the Defiled First Six Consciousnesses?

According to the principle of the twelve links of dependent origination that perpetuate the cycle of birth and death, the cause lies in the manas (intellectual faculty). When the manas is afflicted with ignorance, actions tainted by ignorance arise with ignorance as the condition. With actions tainted by ignorance of the manas as the condition, bodily, verbal, and mental actions tainted by ignorance of the six consciousnesses arise. These bodily, verbal, and mental actions are deposited as seeds within the ālaya-vijñāna (storehouse consciousness). The actions of the manas refer to its volitional choices and decisions. After the manas makes a choice, the six consciousnesses arise to assist the manas in performing actions. Therefore, if the manas is defiled and afflicted with ignorance, the six consciousnesses, acting as assistants, will support 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 mind of the manas. If the manas permits the pure actions of the mental consciousness, then pure karmic actions will arise. Hence, spiritual practice involves cultivating wholesome dharmas and using these wholesome dharmas to influence the manas, thereby eradicating the ignorance of the manas and transforming it. When the mind becomes pure, pure karmic results and virtues will be experienced in the future.