Someone is walking toward you. Having conceptually fixed the person, now you are ready either to grasp or attack him. Automatically, there is an apparatus functioning to provide either a waterbed or a shotgun for that person. That is ordinary intention. It is a thought process which relates thinking to acting. When you encounter a situation you think; and thinking inclines toward action. In your constant alertness to relate the situation to your security, the intention is worked between the two parts of the jaw. The emotional element, concerned with pleasure or pain, expansion or withdrawal, is one part of the jaw; the heavy, physical aspect of the situation is the other. Situations keep you chewing your intention constantly, like gristle. Intention always has the quality of either invitation or attack.
From "The Eightfold Path," in The Myth of Freedom and the Way of Meditation, pages 119 to 120 in the Shambhala Library edition.