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

Because the first six consciousnesses arise depending on the manas's decision-making (the mental factor of volition, cetanā), they come into being for the sake of what the manas needs; whatever the manas needs, the six consciousnesses are born to do. Therefore, if the manas is defiled, the six consciousnesses will follow it in performing defiled karmic actions; if the manas is pure, the six consciousnesses will follow it in performing pure karmic actions. According to the fundamental cause of sentient beings' transmigration through birth and death as revealed by the twelve links of dependent origination, it is because the manas has ignorance (avidyā) that the manas's volitional formations conditioned by ignorance arise; and with the manas's ignorant volitional formations as condition, the six consciousnesses produce ignorant bodily, verbal, and mental actions, all of which settle into the ālayavijñāna and become seeds.

The manas's volitional formations are precisely its decision-making actions. Once the manas makes a decision, the six consciousnesses arise to assist the manas in carrying out its actions. Thus, if the manas is defiled and has ignorance, the six consciousnesses, as its assistants, will help the manas perform defiled karmic actions. However, even if the manas is defiled, when it is not making decisions toward defiled actions, the mind consciousness can rely on its own purity to perfume the manas; and if the manas permits the mind consciousness's pure actions, then pure karmic actions will be produced. Therefore, cultivation means to perfume oneself with wholesome dharmas, and through these wholesome dharmas to perfume and transform the manas, thereby breaking the manas's ignorance and changing the manas. Then the mind becomes pure, and in the future there will be pure karmic virtues to be enjoyed.