[I]t says in the Lotus Sutra, “O Śāriputra! All the buddhas, the Blessed Ones, appear in the world for just one great purpose and reason.” The four meanings of “one great purpose” should be well understood. What are these four?

1. The meaning of that which is unsurpassed indicates [that the tathāgatas appear in the world to show that] there is nothing else [to achieve] but the omniscient knowledge solely of the tathāgatas. Just as it says in the Lotus Sutra, “[The tathāgatas] appear in the world because they want to reveal the insight of the buddhas in order to purify the knowledge of living beings.” “The insight of the buddhas” means the tathāgatas are able to realize the profound truth with their knowledge of true reality.
2. The meaning of sameness indicates [that the tathāgatas appear in the world to manifest] the equality of the absolute body of the disciples, the self-enlightened buddhas, and the buddhas. Just as it says in the Lotus Sutra, “[The tathāgatas] appear in the world because they want to manifest the insight of the buddhas to living beings.” “Equality of the absolute body” means that the absolute body and the buddha-nature are undifferentiated.
3. The meaning of what is not known indicates [that the tathāgatas appear in the world to manifest what is not known] to all the disciples, self-enlightened buddhas, and others who are not able to know the real basis [of the tathāgatas]. “Not able to know the real basis” means they do not understand that there is only the ultimate, unique buddha vehicle. Just as it says in the Lotus Sutra, “[The tathāgatas] appear in the world because they want to enlighten living beings about the insight of the buddhas.”
4. The meaning of wanting to cause [living beings] to realize an irreversible stage indicates that [the tathāgatas appear in the world because they] want to give countless acts of knowledge. Just as it says in the Lotus Sutra, “[The tathāgatas] appear in the world because they want to make living beings enter the insight of the buddhas.”

Furthermore, “to make manifest” means that [the tathāgatas] want to cause all those bodhisattvas with doubts to know a practice in accordance with the truth. Also, “to make enlightened” means to cause those who have not yet produced the thought of enlightenment to produce it, and to cause those who have already produced it to enter the truth (Dharma). Moreover, “to cause to realize” means to cause those who are following heretical systems to produce realization. Also, “to cause to enter” means to cause living beings who have attained the fruits of the Small Vehicle of the disciples to enter enlightenment.