One Ignorant Thought Is Identical to Enlightenment

[C]ontemplating the mind means contemplating that one ignorant thought is identical to enlightenment. The Mahāparinirvāṇa Sūtra says, “Insight [concerning] ignorance is identical to ultimate emptiness.”465 Wisdom concerning emptiness illumines ignorance; [it clarifies the truth] that ignorance is identical to purity [because they are both empty of substantial Being].

To use an analogy, suppose there is a man who is discovered to be a thief; he is then unable to steal.466 If originally there is no place which is defiled by ignorance, then this “way of passionate delusions” is pure. If passionate delusions are pure, there are then no karmic deeds. If there are no karmic deeds, then there are no bonds. If there are no bonds, then one is a free self. If one’s self is free, one is not bound by karma. Who then experiences name-and-form, contact, and experience? Since there is no experience, there is no suffering. If there is no suffering within the aggregates, who then is transient and perishes? This is the virtue of eternity.

Thus one thought in the mind already includes the twelvefold links of conditioned co-arising. By contemplating [these aspects of] conditioned co-arising and constantly practicing the contemplation of eternity, bliss, selfhood, and purity, the mind will thought by thought come to dwell within the secret storehouse [of Buddhahood]. The constant practice of this contemplation is called “being entrusted to the noble womb.”467 If one practices this contemplation diligently and single-mindedly, one will bring to perfection the content of the womb [and advance toward Buddhahood]. If one destroys ignorance, this is called transcending the noble womb [to advance to Buddhahood].

Foundations of T'ien T'ai Philosophy, p 225-226
465
This is a paraphrase. The entire section reads: “Concerning insight, there are three kinds of insight. Bodhisattva insight, the insight of all Buddhas, and insight (concerning) ignorance. The insight of the bodhisattva is identical to Prajn͂āpāramitā. The insight of all Buddhas is identical to the Buddha-eye. The insight [concerning] ignorance is identical to ultimate emptiness.” This passage is not saying that ignorance and insight is the same; it is saying that realizing the truth of emptiness is to have insight into the true nature of ignorance. return
466
The relevance of this analogy escapes my comprehension. return
467
A simile for the bodhisattva stages, which are the “womb” from which a Buddha is born. The bodhisattva stages are called a “noble womb” in the Jên wang ching. The subject is discussed in more detail in Chih-i’s commentary to the Jên wang ching. return