The meaning of bodhi, taken as a whole, refers to all the Buddha-dharmas that should be fully possessed on the path to buddhahood; its levels, from shallow to deep, are many. The very first is the eradication of the view of self (satkāya-dṛṣṭi-prahāṇa), which includes the first fruit up to the fourth fruit of liberation in both ways; then comes the Mahāyāna seeing of the mind, realizing the fundamental tathāgatagarbha of bodhi, all the way to the perfect clarity of the four wisdoms at the buddha-stage. Realizing the tathāgatagarbha counts as realizing bodhi, but it does not equal realizing all of bodhi, because the nature of the tathāgatagarbha is deep and boundless; only when it is realized in full is anuttarā-samyak-saṃbodhi realized. Therefore, realization is only a beginning; there are still many dharmas that must be realized one by one before bodhi can be perfected.
If one merely knows that the tathāgatagarbha participates everywhere, that the traces of the tathāgatagarbha are everywhere, that all dharmas are the tathāgatagarbha, and that the whole is thusness itself—this is merely a theory learned from books. If this theory is not a conclusion drawn after one's own actual realization, then it is merely learning words. Without actual realization, even one's understanding is not deep enough; one cannot even be said to know that it is so, let alone know why it is so—then how can the problem of birth and death be resolved? If one can open a crack in one's field of vision and peer a little bit inside, one will come to know a little bit of the truth.
After some people learn the theory that the whole is thusness itself, they play clever tricks and begin to exercise their imagination, saying that this is thusness and that is also thusness, that thusness is everywhere, and then self-assuredly declare: "Haven't I attained enlightenment?" They then go looking for someone to certify them.
If one can see how the tathāgatagarbha concretely exists and manifests, that would be quite remarkable indeed, and it could be called genuine enlightenment. Studying Buddhism means first eradicating the view of self; only when the principle that the five aggregates (pañca-skandha) are not self has been thoroughly understood will seeing the mind afterwards not be difficult. For example, everyone knows that electric current flows inside the wires, yet the current cannot be seen; one can only see its applications—it makes the rice cooker cook rice, makes the washing machine wash clothes; when your hand touches the current, you get shocked and tremble with numbness—but this still does not count as realizing the electric current. Seeing the washing machine wash clothes and knowing there is electric current relies mostly on theoretical understanding; not yet knowing the concrete function of the current, it does not count as realization.
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