The metaphorical model of Cubism is the diagram: the diagram being a visible, symbolic representation of invisible processes, forces, structures. A diagram need not eschew certain aspects of appearances: but these too will be treated symbolically as signs, not as imitations or re-creations.The model of the diagram differs from that of the mirror in that it suggests a concern with what is not self-evident. It differs from the model of the theatre stage in that it does not have to concentrate upon climaxes but can reveal the continuous. It differs from the model of the personal account in that it aims at a general truth.