As the content of consciousness makes up consciousness, the very content prevents the freedom, the quickness, the marvellous sense of movement. The content of consciousness becomes self-interest. The content may be that you give importance to a piece of furniture, or to some technique, or to some belief or experience: that experience, that knowledge, that incident becomes the centre of self-interest. The emptying of consciousness of all its content is to have total movement in perception and action.