What Is the Meaning of Single Thought Ignorance and Beginningless Ignorance?

The term "One Thought Ignorance" (Yinian Wuming) indicates that thoughts and concepts are tainted by ignorance. Why are they ignorant and defiled? Because the mind harbors the notion of "self," taking the five aggregates and eighteen realms as the self and what belongs to the self. It fails to recognize that this so-called self is characterized by suffering, emptiness, impermanence, and non-self. All thoughts and concepts revolve around this self and its possessions, firmly clinging to this illusory "I," thus binding one firmly to the cycle of birth and death. When thoughts centered on the self guide bodily, verbal, and mental actions, these actions inevitably become defiled karma. This defiled karma, in turn, inevitably perpetuates the endless cycle of birth and death. Therefore, One Thought Ignorance perpetuates all forms of birth and death, preventing liberation.

However, One Thought Ignorance is also a form of Beginningless Ignorance (Wushi Wuming), which has existed since time without beginning, having no point of origin. If it had a beginning, then prior to that time, One Thought Ignorance would not have existed, and sentient beings would have been Arhats, abiding in the state of Nirvana without residue. In Nirvana, there are no sentient beings, nor are there Arhats. All ignorance has existed primordially since time without beginning; it is all Beginningless Ignorance. It is only through the influence of subsequent environmental conditions that Beginningless Ignorance increases or decreases.

After One Thought Ignorance is completely eradicated, Beginningless Ignorance still remains to be fully extinguished before Buddhahood can be attained. Beginningless Ignorance is the fundamental misconception held by sentient beings since time immemorial: the belief that the world of the five aggregates is real. They fail to realize it is merely an illusory manifestation projected by the Tathagatagarbha, failing to perceive its emptiness. It is due to this that the clinging to self (ātma-grāha) and clinging to phenomena (dharma-grāha) arise, leading to the cycle of birth and death in segments (fenduan shengsi) and the cycle of birth and death through transformation (bianyi shengsi), preventing liberation. To eradicate Beginningless Ignorance requires the practice of Chan meditation (contemplation), leading to the direct realization of the Tathagatagarbha and the true suchness (tathatā) of all dharmas. Progressively realizing the nature of the One True Dharma Realm, one fully realizes the true Dharma-nature of all phenomena. This results in the complete transformation of consciousness into wisdom (zhuan shi cheng zhi), thereby accomplishing the Buddha Way.