MARGARET Hell, do they ever know it? Nobody says, "You're dying." You have to fool them. They have to fool themselves.(I.25-26)
Maggie seems to be the master of manipulation. She seems to know what it takes to get through ordeals: this, according to her, is achieved by swimming in denial.
MARGARET But tonight they're going to tell her the truth about it. When Big Daddy goes to bed, they're going to tell her that he is dying of cancer […] –it's malignant and it's terminal. (I.819-823)
It's interesting that they don't tell Big Daddy the truth right away. Everyone wants to put on a good show before he hears the news.
MARGARET Yes, I made my mistake when I told you the truth about that thing with Skipper. Never should have confessed it, a fatal error, tellin' you about that thing with Skipper. (I.919-922)
Maggie again seems to feel like truth-telling is a destructive thing, and far worse than lying.
MARGARET In this way I destroyed him, by telling him truth that he and his world which he was born and raised in, yours and his world, had told him could not be told? (I.59.1126-1128)]
Maggie has seen the destructive power of truth, its ability to kill. Truth kills when what it reveals lies outside of societal expectations.
MARGARET I'm honest! Give me credit for just that, will you please? (I.1140)
Maggie isn't entirely honest, though. She's complicit in the lie everyone has told Big Daddy about his spastic colon. She lies about her pregnancy at the end of the play.
BIG MAMA And I did, I did so much, I did love you!—I even loved your hate and your hardness, Big Daddy! […] BIG DADDY Wouldn't it be funny if that was true… (II.364-368)
It's hard to believe that Big Mama doesn't love Big Daddy, considering the show of affection she demonstrates every time he's around. We never see Big Daddy and Big Mama alone, and so we don't really know them as intimately as we know Brick and Maggie.
BIG DADDY Uh—huh. Expecting death made me blind. I didn't have no idea that a son of mine was turning into a drunkard under my nose. (II.99.816-818)
Death's momentary release of Big Daddy gives Big Daddy perspective. Big Daddy's flirtation with death makes him want to hunt down the truth.
BIG DADDY Think of all the lies I got to put up with! Ain't that mendacity? Having to pretend stuff you don't think or feel or have any idea of? Having for instance to act like I care for Big Mama!—I haven't been able to stand the sight, sound, or smell of that woman for forty years now!—even when I laid her! (II.108.996-1002)
Big Daddy is successful and wealthy, but his success and wealth are constructed out of the lies he tells Brick.
No!—It was too rare to be normal, any true thing between two people is too rare to be normal. (II.121.1271-1272)
The only true relationship in the play is a memory and no longer exists. Normal, accepted relationships are those built upon lies.
BRICK Maybe it's being alive that makes them lie, and being almost not alive makes me sort of accidentally truthful—I don't know but—anyway—we've been friends…(II.128.1440-1443)
Here again we see the association between lying and life, as well as between truth and death. It would seem that truth can only be found through death.
MARGARET And so tonight we're going to make the lie true, and when that's done, I'll bring the liquor back here and we'll get drunk together, here, tonight, in this place that death has come into…. (III.165.770-773)
Maggie wants to find a way to do the impossible: to create truth in a world constructed of lies. If she succeeds, she'll be the only character able to do this.