In his attempt to explain the difference between Importance ans Expression to Grendel, the dragon uses the examples of the difference between vegetables and animals and the difference between an angry man and a rock. Explain.

The dragon tells Grendel about nature's inevitable movement towards complexity. He explains that a vegetable does not change when split up. Its molecules remain intact: one can grow another vegetable from part of the vegetable. The animal however has a head, which controls the rest of the organism. Without the heat, the entire organism dies. Similarly a rock is a simple object; it has no reason or control over its environment. A human, however, can make choices and can adapt to his environment.