The four types of regulating and rectifying bring about the illumination of perfect quiescence in one life. The five categories of preparatory practices train one’s uncontrolled physical, verbal, and mental actions. Though one experiences craving, one nevertheless can gain enlightenment concerning bodhi-wisdom. By contemplating [the cycle of] birth and death one is awakened to Nirvāṇa. One crosses over this realm of delusion on the raft of practice, and thus completes this doctrine. Where else can one seek the torch of wisdom [that illumines] this dark room? …

Q: What is the list of names [of the Four Samādhis]?
A: (1) The Constantly Sitting Samādhi; (2) the Constantly Walking Samādhi; (3) the Half-walking and Half-sitting Samādhi; and (4) the Neither-walking-nor-sitting Samādhi. …

Q: What is the interpretation of the names?

A: “Samādhi” refers to regulating, rectifying, and concentrating.

Q: What is regulated to justify calling it “regulating and rectifying”?

A: Physical, verbal, and mental [activity] are regulated and rectified.

Q: How do you know that “samādhi” means regulating and rectifying?

A: The Ta Chih tu lun says, “A good mind dwells in one place without moving. This is called samādhi.”

Q: What is the meaning of this treatise passage?

A: “One place” refers to the Dharma realm. In [the state of] cessation and contemplation one can concentrate without wavering. With these four practices as conditions, one contemplates the mind, and with these conditions one regulates and rectifies [physical, verbal, and mental activity]. Therefore it is called “samādhi.”