The Difference Between Chan Contemplation and Logical Reasoning

Chan investigation (canchan) is the practice method of seeing one's true mind and attaining realization that was advocated by the Chan patriarchs of the past; through this method of Chan investigation one can realize the original mind, the self-nature, the eighth consciousness. Chan investigation requires profound meditative concentration (samādhi), the ability to apply effort from morning to night without interruption, with the mind engaged in investigating and seeking the Way throughout the six periods of the day and night, with refined and subtle thinking. When the conditions ripen, upon encountering conditions and circumstances one can awaken at any time by oneself, or awaken under a Zen master's repartee. In the early stage, when the skill is not yet pure, Chan investigation is called "seeking" (vitarka), where the mind consciousness applies effort more forcefully, with more and more evident deliberation. As meditative concentration deepens and the skill matures, one enters the stage of sustained examination (vicāra), where the mind consciousness can no longer apply deliberate effort, and the deliberation (manana) of the manas manifests. Only then can one apply effort from morning to night, awake or asleep, day and night, merging it all into one whole, with doubt deepening to the utmost, so that the mind becomes extremely keen; upon encountering corresponding states, realization occurs and meditative concentration (samādhi) is attained. If meditative concentration is shallower, the skill cannot go deep, and the samādhi-and-wisdom state of realization will not arise.

Logical reasoning and logical thinking, however, fall entirely upon the mind consciousness; the skill involved is relatively shallow, and it works with or without meditative concentration—even middle school students can use logical thinking and reasoning to resolve questions in their studies, and everyone from academic researchers at all levels commonly uses logical reasoning; even those who have meditative concentration have only rather shallow concentration. Logical thinking and reasoning correspond to the introductory stage before formal Chan investigation; once one has entered the gate, logical reasoning may no longer be used. Logical reasoning is a great taboo in Chan investigation, something all Chan patriarchs strenuously opposed, calling it "divination beneath consciousness," "emotional thinking and intellectual understanding," and "ghosts' tricks." Chan masters strictly prohibited their disciples from divining and scheming opportunistically in their minds, and required them to investigate apart from mind, consciousness, and mental states—that is, not allowing the use of the mind consciousness's thinking, and investigating apart from all language, words, and sounds.

When the mind consciousness has language and words, meditative concentration is certainly very shallow or absent. When meditative concentration is deep, the mind consciousness cannot have coarse, shallow thinking activity; even subtle thinking activity ceases, yet this does not obstruct the manas's deliberation. The Buddhas even attained the Way within the fourth dhyāna; ordinary people's mind consciousness loses its thinking at the second dhyāna, and in the third and fourth dhyānas the mind consciousness's thinking is extinguished even more, although the mind consciousness still exists without perishing and retains an extremely deep and subtle knowing nature. Therefore deeper meditative concentration can suppress the mind consciousness's thinking while stimulating the manas's deliberation. When the mind consciousness and the manas exist together, their deliberative activities wax and wane against each other: if the mind consciousness's thinking is too active, it obstructs the manas's deliberation, and the manas cannot apply itself.

Logical thinking and reasoning both involve language and words; apart from language and words, these are all activities of the mind consciousness's thinking, in which the manas cannot exert itself, and therefore the manas will not realize the final correct result. Because the manas has no language or words, true Chan investigation is led primarily by the manas. What the Chan patriarchs meant by "investigating apart from mind, consciousness, and mental states" is precisely not allowing coarse, shallow thinking of the mind consciousness.