Thesis

The controlling idea of an essay stated in one sentence, usually the last sentence in the introduction. This is where you state the argument your essay will prove.

Examples
Sammy is an everyday hero.
While flawed, Abner Snopes is not meant to be completed reviled.
Norma Jean commits suicide at the end of "Shiloh."

These are interpretations of the story that need to be proven. The specific reasons that would prove these are called divisions.