So the practice on retreat should proceed as follows. You begin at the normal, everyday level. After working hard you enter a stage where everything suddenly becomes abnormal. Then, after a life and death struggle, you enter the door of Ch'an and again see everything as normal. But don't be misled; this "normal" is quite different from the "normal" of the man on the street. At this point the practitioner's mind is quite clear, but he should press onward until he reaches a higher abnormal stage. Kung-ans such as "Where am I?" represent the normal stage just after entering the door, whereas the "egg and the rock" type of kung-an represents the second abnormal stage. This is followed by still deeper abnormal stages. Ch'an masters have used various ways to chart the stages of progress one should pass through. Some speak of passing three major barriers, others set up four stages, but these are just rough classifications. Generally speaking, a person will go through tens or even hundreds of changes from abnormal to normal, from negation to affirmation, before reaching perfection. If you want to accomplish this in one lifetime, you must genuinely practice very hard every moment.

How can practicing Ch'an change your perceptions and attitudes? It can by using great pressure to uncover and completely utilize your hidden mental power. It's like physical power. We know we have a lot of hidden physical power that can be used in extreme situations. For example, a person being chased by a tiger may suddenly find the strength to run faster than he normally could. Things like this happen. You don't know where the strength comes from, but you somehow find it when you need it. Similarly, Ch'an is a method for putting a student in a desperate mental situation, forcing him to use his hidden power to save himself.

To reach this stage, a student must first attain a certain degree of concentration. Without it, he can't even begin to practice Ch'an. Then he must advance to a samadhi-like stage, which we call "meditation." When your mind is powerfully concentrated, and free of stray thoughts, you are ready to t'san ch'an, or "investigate Ch'an, " to practice kung-an.