Poetics

I was looking through my writer's books for something to chew on and picked up Aristotle's Poetics translated by Gerald F. Else.

Here's something valuable:

...component events ought to be so firmly compacted that if any one of them is shifted to another place, or removed, the whole is loosened up and dislocated; for an element whose addition or subtraction makes no perceptible extra difference is not really a part of the whole.