All Buddhist meditation aims at the development of awareness, using concentration as a tool. The Buddhist tradition is very wide, however, and there are several diverse routes to this goal
. Zen meditation uses two separate tacks
. The first is the direct plunge into awareness by sheer force of will. You sit down and you just sit, meaning that you toss out of your mind everything except pure awareness of sitting.
This sounds very simple. It is not. A brief trial will demonstrate just how difficult it really is. The second Zen approach used in the Rinzai school is that of tricking the mind out of conscious thought and into pure awareness. This is done by giving the student an unsolvable riddle which he must solve anyway, and by placing him in a horrendous training situation
. Since he cannot flee from the pain of the situation
, he must flee into a pure experience of the moment. There is nowhere else to go. Zen is tough. It is effective for many people, but it is really tough.