Why Is Manas the Governing Consciousness?

Manas is the decision-making consciousness. Among the five aggregates and eighteen elements, all matters great and small are directed and commanded by manas; nothing can substitute for manas, not even the mental consciousness. Although the mental consciousness's thinking and judgment can guide manas's choices, the ultimate decision-maker remains manas. Tathāgatagarbha cannot make decisions in place of manas, cannot command the bodily, verbal, and mental actions of the six consciousnesses, and cannot take charge in worldly matters.

Because tathāgatagarbha is devoid of self-nature and does not perceive worldly phenomena—what it perceives are solely non-worldly phenomena—it cannot govern matters of worldly nature nor direct the creation of worldly phenomena. It cannot possess the mental activities of "self" like manas does; lacking the notion of "self," it does not assume control.

Cultivation involves eliminating the ignorance of manas, enabling it to recognize that the five aggregates and eighteen elements are not the self, and to understand that the true master is tathāgatagarbha—that all phenomena are illusory appearances manifested by tathāgatagarbha, not inherently possessed by manas itself. Only then can manas gradually eradicate the attachments to self and phenomena. When all attachments are exhausted, one attains Buddhahood.