1. Unity and Disunity
The system and coherence of the narrative film, its abhorrence of non-functional elements, and its apparent organic unity are often presented as ideals. Most Hollywood films aspire to be tight and unified, with everything meaningful and in place. Few succeed entirely, and some don't succeed at all. While aspiring to unity almost all narrative films incorporate, consciously or not, elements of disunity. Rather than all the motifs harmonizing, as it were, there are often some wrong notes.
More importantly, some films strategically and systematically build themselves on principles of disunity. The "montage" style of Soviet films of the 1920's are one example. Rather than assimilating shots into the impression of a continuous space, they stressed the formal integrity of the shot and the shock of the cut.