Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
What we’re getting at here in our discussion of "Tone" is Williams’s attitude toward his protagonist, Blanche DuBois. We admit that Blanche comes off as quite silly for a good chunk of the text (spraying Stanley with her perfume, flirting with the men at the poker table), but it’s actually more tear-jerking than laughable. She's unstable from early on, and totally terrified:
… I want to be near you, got to be with somebody, I can’t be alone! Because—as you must have noticed—I’m – not very well… [Her voice drops and her look is frightened.] (1.141)
We feel bad for her—and probably embarrassed on her behalf. The rape in Scene Ten and the broken-down Blanche in Scene Eleven is what really drives the point home, and what convinces us that the play takes a sympathetic approach—not a ridiculing one—to this fading Southern belle:
You know what I shall die of? I shall die of eating an unwashed grape one day out on the ocean. I will die – with my hand in the hand of some nice-looking ship’s doctor, a very young one with a small blond mustache and a big silver watch. […] And I’ll be buried at sea sewn up in a clean white sack and dropped overboard – at noon – in the blaze of summer – and into an ocean as blue as my first lover’s eyes! (11.69)
If you don't read this mini-monologue and think "Poor Blanche," then you should have your heart checked. It might be made out of ice.