“Tragedy is an imitation of an action that is complete, and whole, and of certain magnitude. … A whole is that which has a BEGINNING, a MIDDLE, and END. … A well constructed plot, therefore, must neither begin nor end at haphazard, but conform to these principles.”
(Poetics, Part VII)
The above definition may seem so self-evident as to be verging on goofy. Seriously, does anyone not know that a story has a beginning, middle, and end? But stop snickering. You can begin or end a tale at any of an infinite number of points. Knowing where those points are is what defines your story and what often makes the difference between a good one and a bad one.
For Aristotle, a well-told story must start at a specific ...