The manas and mental factors are the guiding principle of actual practice, and also the operating system of actual practice.

The mental factors (caittas) of the manas are the guiding principle of actual practice, and they are also the operating system of actual practice. "Guiding" means that the mental factors can point toward the goal of one's own practice; "principle" means returning to the transformation of the mental actions and mental factors, as well as the transformation of karmic seeds, so that one's mental actions become pure. The operating system means following the mental factors and continuously transforming them; actual practice is precisely the process of operating the mental factors, or the process of being operated by the mental factors.

The fundamental cause of the change in mental factors is the tathāgatagarbha, but the tathāgatagarbha is not the master consciousness; it has no subjective initiative, does not make decisions, and is passively employed by the manas. Although the arising of all things is produced by the tathāgatagarbha, the driving force is the mental factors of the manas. If the manas does not desire to do anything, the tathāgatagarbha does nothing, and no dharmas arise at all.

The manas has subjective initiative; it is the transformation of the manas's mental disposition that prompts the change of karmic seeds. The transformation of the manas's mental factors is the cause, and the change of karmic seeds is the effect. Karmic seeds are formed when, after the manas desires to do something, the tathāgatagarbha cooperates by producing the six consciousnesses to create karma. Otherwise, there would be no karmic seeds. Of course, in actual genuine practice, every step will cause changes in the manas's mental factors, and the change in mental factors is the effect. The cause is still the manas's mental factors prompting changes in its own mental factors, with the precondition being that the mind consciousness's mental factors push the manas's mental factors.

However, the appearance of many dharmas is not driven by the mind consciousness, but is driven entirely by the manas alone. For example, before the five aggregates of grasping were born, there was no mind consciousness; it was the manas that prompted the tathāgatagarbha to produce the universe's material environment for existence, and then to produce the body of the five aggregates, only then did the mind consciousness exist, only then were there the actions of the five-aggregate body, and only then did karmic seeds appear. Before waking up from sleep, there is no mind consciousness; it is because the manas wants to wake up that one can then wake up. When one is in a coma, there is no mind consciousness; it is the manas that, according to the body's condition, wants to wake up, and only afterward does one wake up. In the mother's womb, at first there is no mind consciousness; it is the manas that wants to enter the womb and thus enters the womb, wants to dwell in the womb and thus dwells in the womb, and wants to be born and thus is born.