The structure of this play is best seen through a series of confrontations between Blanche DuBois and Stanley Kowalski. In the first scene the confrontation is not so severe, but it increases in severity until one of the two must be destroyed. To understand fully the scenes of confrontations, readers should have a good understanding of what is at stake in each encounter. That is, they should understand some of the differences between the DuBois world and the Kowalski world.
The most obvious difference between the worlds of Blanche DuBois and Stanley Kowalski lies in the diversity of their backgrounds. We immediately recognize that the very name DuBois and Kowalski contrast. Williams has begun to sketch the personalities by a nationality association. We assume DuBois to be an aristocratic name, possibly one with a proud heritage. A DuBois wouldn't be found working in a steel mill, as would a Kowalski. A DuBois speaks softly and flittingly. A Kowalski speaks loud and brutally. Kowalskis relish loud poker parties with their characteristic rough humor. Blanche DuBois winces at this. Her preferences for entertainment are teas, cocktails, and luncheons. Speech, to Stanley, is a way of expressing his wants, likes, and dislikes. Blanche speaks on a higher level. She searches for values, reflecting education in her manner of speaking. Kowalski regards money as the key to happiness; money will buy anything. Stanley's interest in Belle Reve centers only upon the fact that under the Napoleonic Code he loses money. He cares nothing for the tradition of the place but only its financial value. Money, to his type, is a power that can buy some basic wants or pleasures of life. This gives him a type of animal superiority to the world of people (like the DuBois) who do not understand the value of money and then become destitute.
Stanley and Blanche, as individual representatives of these two worlds, show even more contrasts in their personalities. The use of color differs remarkably. Stanley needs vividness to prove his physical manhood. He is presented "as coarse and direct and powerful as the primary colors." His green and scarlet bowling shirt is an example. Blanche shuns loud shades and selects pastels or white. The directness of bright colors repulses her; she prefers muted, muffled tones.
Another contrast arises in the comparison of their zodiac signs. Stanley was born in December under Capricorn the Goat. This brings to mind many obvious associations in connection with Stanley's personality. Blanche's sign is Virgo, the virgin. True, she is a very degenerate "virgin," but in body only. She tries to keep the mentality of a virgin. She believes she is a virgin because the men she has slept with have meant nothing to her; they have not actually taken from her. She has not given of her real self to them. But to represent herself in such a manner seems a direct lie to the Kowalski world. There can be no such subtle difference in the Kowalski world. This leads to one of the central conflicts of the play, Blanche's honesty versus her seeming dishonesty.
A Kowalski, as seen in Stanley, is "simple, straightforward, and honest." He tolerates nothing but the bare, unembellished truth. Blanche, so to speak, "puts a gaily-colored paper lantern" on the harshness of truth. This isn't lying to her. A lie, for Blanche, would be a betrayal of herself, of everything she believes in. Therefore, it would not only be a verbal lie but also a lie in act. Stanley abhors the paper lantern. He accepts it for nothing other than a lie and detests Blanche for deceiving others with it. This conflict is irresolvable because it originates in the essence of their personalities. To concede to the other's view entails self-destruction.
Love is essential to both worlds but has entirely different significance for each. Stanley needs love to satisfy his animal desires. To him it is the physical act of love, no more. Blanche's sensitivity is the key to her approach to love. She needs someone not to fulfill her basic physical desires but to protect her or she feels the need of giving herself to someone. Her concept of love is on a higher level than Stanley's. Shunning the brutality and animality of a Kowalski, she seeks some type of communication, some capacity for devotion. Desire isn't the lustful passion that Stanley regards it, but it is a spiritual need. Speaking of Mitch, Stella asks her, "Blanche, do you want him?" She answers, "I want to rest. I want to breathe quietly again." She seeks security and protection for her sensitiveness against the rough edges of her surroundings.
The symbol employed most frequently by Williams in his emphasis of the essential differences in the worlds is light. It represents the reality Stanley lives by and the harshness Blanche must soften. He faces it because it is him; he is "a naked light bulb." He faces the way things are, doesn't delude himself into believing they are something else. Blanche did that once when she saw the truth about her young husband, and it nearly broke her. Since then she has retired into a world of shadow and illusion. "There has never been any light that's stronger than this — kitchen — candle." If she must have a light, she prefers candlelight. The light in her room is too strong for her; so she covers it with a paper lantern. She uses this in a symbolic explanation of her own approach to reality: "soft people have got to court the favour of hard ones... have got to be seductive — put on soft colors . . . shimmer and glow." This then is the only way in which Blanche can cope with Stanley's world, but his world forbids it. She must improvise, make the necessary adjustments. He tolerates no compromise. His primitive, honest manner threatens to destroy her. The two ways of life are totally incompatible; there can be no peaceful coexistence.
Thus the play is structured on the principle of presenting the two worlds, establishing what each world believes in, and then placing these worlds in a series of direct confrontations until one is destroyed.