The great achievement of D. W. Griffith was not this or that narrative technique of editing or shooting but his realisation that the image had first to be detached from what it represented enabling it to attain autonomy and independence as an image. Autonomy allows images to be related one to another, to become 'writing', and to return to reality indirectly by images of it, the writing of a story with images of absent realities. This realisation gives Griffith's films an uncertainty and fragility as if representation is made relative by the realities it can never fully grasp and that threaten its disappearance. His fictions had realistic aims achieved by unrealistic means. Griffith was an inventor, creator and champion of cinematic forms, largely attentive, seldom negligent. Alternating montage is ruled by temporal and causal rules, for example, in a chase scene or a shot counter-shot in a scene of dialogue.