It is this difference which causes duality, and it is this duality which maintains the existence of things. The finer aspect of this phenomenon can be seen in musical rhythm. When we say, "one-two, one--two", then we understand what it is that makes us emphasize the one, and what it is that makes the two like an echo, a reflection, something that responds to the one. And suppose we do not say, "one - two", that we only say, "one - one - one -one - one", all with the same emphasis, this will not satisfy us. We will not feel any rhythm until the one becomes accented and the two, or whatever we say next, follows it; then it becomes perfect. We see the same happening with the action of walking, which is accomplished by both legs: if we practice walking on one leg we will find something missing in the rhythm.