The poet asks us to literally look upon the body as non-existent. In Buddhist analysis, form, taken to be the physical world, is the first of the five skandhas, or phenomenal aggregates. These aggregates, or "heaps, " together create the illusion of existence. Form is the material component. The other four skandhas ─ sensation, perception, volition, and consciousness-are all mental components. A person who is able to contemplate the five skandhas well would be considered enlightened. In Buddhist analysis, the body is composed of the four elements: earth, water, fire, and wind. If we were to separate these elements, our body would not exist. Why do these elements combine? They come together because of the force of our previous karma. A body which is thus compounded is not genuinely real. Being the result, or the reflection, of our previous karma, it is like the reflection of the moon in water. If the mind didn't create karma, then the elements would not accumulate and combine to make up the body. If we take this body, this result of previous mental karma, as real, then it's like looking upon the moon in the water as the real moon. Further, the body is in a constant state of change, and has no truly fixed existence. If we can realize the illusory nature of the body, the mind will settle down and our vexations will clear up. All our vexations, associated with greed, hatred, and delusion, arise because we identify with the body, and want to protect it and seek benefits for it. Because of the body, we give rise to the five desires, namely, food, sex, sleep, fame, and wealth. To undo vexations, first break the attachment to the body; then break away from the view that the body is truly substantial. But this view is very difficult to break. In the sutras it is said that sakaya, the view of having a body, is as difficult to uproot as a mountain. So, Han-Shan tells us, once we can see the body as unreal, we can begin to work on the mind.