The Investigation of Huatou Requires Access Concentration and the First Dhyāna

Question: If the Path of Insight requires the states of access concentration (anāgamya-samādhi), first dhyāna, second dhyāna, third dhyāna, and fourth dhyāna, does the Chan (Zen) practice of investigating the huatou (critical phrase) to attain enlightenment and realize the Path accord with Buddhist principles?

Answer: Without access concentration or the first dhyāna, one cannot genuinely investigate the huatou; one can only repeat the huatou mentally. In truth, this is merely repeating its "tail," for the "head" of the huatou cannot actually be found. How, then, can one speak of enlightenment and realizing the Path? However, it is precisely before attaining the first dhyāna that one can engage in Chan investigation and attain awakening. Beyond the second dhyāna, the five sensory consciousnesses cease, and mental consciousness becomes extremely subtle, making Chan investigation impossible—unless the mental faculty (manas) has been deeply and profoundly conditioned by the huatou, in which case solitary investigation might still occur. In the past, Chan patriarchs attained awakening within the concentration states preceding the first dhyāna. They cultivated stillness through seated meditation and engaged in Chan investigation during daily activities. These two forms of concentration complemented each other, accelerating the path to awakening. Relying on only one of these approaches makes attaining awakening considerably more difficult.