In the Spirit of Ch'an 18
Ch'an master Dahui Zong gao (1089-1163), one of the greatest advocates of huatou practice, maintained that sitting meditation is necessary to settle the wandering mind before a student can effectively use a gong an or huatou. A scattered mind lacks the focus or energy necessary to generate the great doubt, so in training my students, I first give them a method to unify the scattered mind. Once the student's mind is stable and concentrated, the application of gong an orhuatoumay cause the great doubt to rise. This doubt is not the ordinary doubt of questioning the truth of an assertion. It is the fundamental uncertainty, the existential dilemma, that underlies all of our experiences ─ the question of who we are and the meaning of life and death. Because the question inherent in the gong an or huatou cannot be resolved by logic, the practitioner must continually return to the question, nurturing the "doubt mass" until it is like a "hot ball of iron stuck in his throat." If the practitioner can persist and keep the energy from dissipating, the doubt mass will eventually disappear in an explosion that can wipe away all doubt from the mind, leaving nothing but the mind's original nature, or enlightenment.
It is also possible, and perhaps more likely, that the explosion will lack sufficient energy to completely cleanse the mind of attachment. Even as great a master as Dahui did not penetrate sufficiently in his first explosive experience. His teacher Yuanwu (1063-1135) told him, "You have died, but you have come back to life." His enlightenment was confirmed on his second experience.
Therefore, it is very important to have a reliable Shifu, or teacher, guiding one through all stages of practice. At the outset, attempting to generate the great doubt before the mind is sufficiently stable would, at best, be useless and, at worst, give rise to a lot of anxiety. And finally, any experience one has as a result of the practice must be confirmed by an adept master. Only a genuine master will know the difference between a true and a false enlightenment.
The practice of gong an and huatou is an aggressive, explosive approach toward enlightenment; the practice of silent illumination is a more peaceful way. Both, however, require the same foundation: a stable and unified mind. And both have the same purpose: the realization of the nature of mind, which is the nature of emptiness, Buddha-nature, wisdom and enlightenment.