Why is contrast contained by stories efficient?

I am writing about how the contrast of hope helps establish the theme of isolation. Why do you deliberate this is an effective technique used by an author?
Answers:
?

The contrast between hope and what?

EDIT:
Sorry, still confused.

The contrast between hope and hope of acceptance?

2nd EDIT:
I've starred this one for you in hopes that someone else will come along and answer your press.

I've read it twelve times and I still don't understand what you're asking.

Must be too much coffee.


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