I think that one of the strongest aspects of naturalism present is the basic depiction of ordinary people in extraordinary circumstances.  Stanley, Stella, Blanche, and Mitch are all regular people.  There is nothing extraordinary about them.  However, Williams places them in the fundamental collision between modernity and tradition.  Stanley is a regular, working class protagonist who is meant to represent the modern setting of pragmatism and materialism.  Blanche is a Southern woman, typical of the context, but one shoulders the burden of the past with her embodiment of Belle Reve values and the tradition of the "old South."  She is ordinary, which might belie what she actually feels about herself as being something uniquely different.  Stella is poised between both of them, a regular person in an emotional dynamic that is anything but regular.  These characters act in an ordinary manner, representing themselves and their own senses of self.  Yet, it is through depicting them in common conditions that Williams is able to bring out their humanity, or lack of it, and forge connections with the audience.

As I understand it, the difference between naturalism and realism in fiction is that naturalism strives to be more interesting by being more dramatic while still maintaining its atmosphere of realism. Reality is not necessarily interesting. In fact, it is usually pretty boring and monotonous, as most of us can attest from our own lives. With naturalism, interesting things happen to the characters in a realistic setting and in a realistic way. A lot happens in "A Streetcar Named Desire," but it all seems to be happening to ordinary people who just happen to be going through one of the critical periods that occur in every life. This is something we have all experienced in our own lives, too. There were many days when nothing happened. There were emergency situations that came up--often completely unexpectedly--and then our lives went back into the normal mode of reality. Theodore Dreiser's great novels "Sister Carrie" and "An American Tragedy" are examples of naturalism. James T. Farrell's "Studs Lonigan" is a good example of realism. The contrast between realism and naturalism in fiction is interesting. Realism seems more authentic, but naturalism is more interesting because it is more dramatic and hence more exciting.

"A Streetcar Named Desire" seems realistic because of the setting, the dialogue, the crude behavior of some of the male characters, the long passage of time during which nothing much happens, and other such aspects of reality. It is naturalistic because there is a serious conflict involved leading to a tragic ending.

Naturalism was first began by French writer Emile Zola. Zola forged the road for other authors who wished to pull away from the Romantic ideas of writing. Romantics viewed life through "rose-colored glasses" (meaning they forced the beauty of all things to the front). In essence, in their desire to elevate nature and the beauty of nature, Romantics tended to alter the realities of life.

Naturalists, on the other hand, desired to show life as it really was (as an extension of Realism). The authors tended to be metaphorical scientific observers, stating only what they observed in life without manipulating it.

In regards to Williams' play, A Streetcar Named Desire, the text can be seen as containing Naturalistic characteristics. Symbolism is very important in Naturalistic writings. The play offers many different examples of symbolism. For example, the symbolism of both the streetcars and the light bulb is essential to the play. Both have multiple meanings which blossom over the course of the play.

Naturalists also elevated the importance of nature. Unlike the Romantics who idealized nature, Naturalists believed that nature was the most powerful "being" (given its tendency to be personified) upon earth. In the play's case, the nature of both Stanley and Blanche are very important. Their nature is what leads to the explosive climax.

Naturalists also tended to portray realistic characters in realistic settings. Working class characters who lived normal lives with normal struggles tended to be the focus of the characterizations created for Naturalistic pieces. The fact that the play takes place in a rundown area of New Orleans and depicts normal working class characters (like Mitch and Stanley) proves the setting to be one typically found in Naturalistic writings.

American Naturalism, which differs somewhat from European Naturalism, is heavily influenced by the idea of determinism--the theory that heredity and environment determine behavior.  Naturalism is connected to the doctrine of biological, economic, and social determism.  Naturalist writers strive to depict life accurately--much like realists--through an explanation of the causal factors that have shaped a character's life as well as a deterministic approach to the character's actions as determined by environmental forces.

Major themes of the Naturalists are man against society; violence; the consequences of sex and sex as a commodity; the waste of individual potential because of the conditioning forces of life; and man's struggle with his basic, animalistic instincts. 

In Tennessee Williams's A Streetcar Named Desire, many of these thematic concerns are present.  Both Blanche and Stanley struggle with their basic instincts.  But, because Blanche is a woman, she has a tarnished reputation and she was dismissed from her position as a teacher because of her association with a student. Stanley projects the violence that is in man's nature, as well.  The conflict between Stanley and Blanche has been viewed also by critics as symbolically the Old South's decline under Industrialization.  This conflict is predetermined as Blanche is a product of the aristocratic, more genteel way of life while Stanley is a product of the new social order.  When, for example, he utters his passionate outburst that he is not a "Polack," but an American citizen, Stanley declares himself part of the new society of multi-cultural America.  His desire for power as such is exerted in his animalistic behavior and his violence towards his wife and Blanche alike.  The tragic figure of Blanche is a result, too, of her social determinism.  Certain causal factors, such as the discovery of her young husband's homosexuality, have determined Blanche's lowered self-esteem and her self-deception.

Brutal at times in its depiction of life, A Streetcar Name Desire stands as a stellar example of literary Naturalism.

In A Streetcar Named Desire, how is naturalism depicted?

Realism was a literary period which came about in the mid-nineteenth century. Realism depicted life as it really was, using common settings and characters. Not completely happy with the genre of Realism, Naturalists emerged in order to illuminate, and change, specific ideas within Realism.

Naturalists used common settings and characters in the same way Realists did. Naturalists also took an objective stand when it came to the point-of-view. Both Realists and Naturalists did not want to "interfere" with the story being told. Instead, "their" narrators mirrored scientists (in regards to how they simply recorded the "facts" as they happened). The narrator was not allowed to interfere with the story.

Perhaps the most important characteristic of Naturalism is the giving of power to nature. For the Naturalist, nature was more powerful than anything else, mankind included.

In regards to Tennessee Williams' play A Streetcar Named Desire, one could define specific characteristics which are Naturalistic in nature.

First, the setting is very realistic and common. The play takes place in Elysian Fields, a neighborhood in New Orleans. The setting is described exactly as one would expect to find in a rather poor, working-class section of the city. The music is also typical of the time and place.

Second, the characters are realistic and common. Stanley is the typical working-class man's man. He swears, drinks, bowls, and openly abuses his wife (which is accepted and forgiven by Stella). Blanche is the epitome of the broken and aging Southern Belle. Essentially, the play is filled with stock characters.

Lastly, no matter what any of the characters do, nature "wins." Blanche, in order to hide her aging, covers light with paper lanterns. In the end, Mitch removes the lantern and sees that she is older than she has stated (showing that man cannot cover up the natural aging process). Also, Stanley's brutish nature is far more powerful than anything else. His rape of Blanche shows the natural power of man over woman. Lastly, Blanche's diminishing mental nature cannot be stopped. In the opening, readers can see that Blanche is "not quite right." Her behavior and dialogue is confusing at times, and she tends to believe in alternate realities. In the end, the nature of her brain's weakness cannot be stopped. 

How is Naturalism depicted in Act I, scenes 1 and 2 of A Streetcar Named Desire?

Naturalism is a literary movement which focuses on very specific aspects of life. The characteristics of Naturalistic texts contain the following ideals:

1.  The text is written from an objective point-of-view. This means that the author writes from a scientific perspective similar to that of an experiment. The author states that they are simply describing the action of what is happening- they do not attempt to change or influence the character or the action of the text in any way.

2. The characters described are typically deterministic. The protagonist simply sees a problem with the circumstances that they have found theme selves in, or other characters in, and wishes to change them.

3. Given the text is written from an objective point-of-view, the text is also pessimistic and emotionally cold. The author is, again, only describing what they are "seeing" from a observers point-of-view. They wish to have no compassion for the characters because it would force them to interfere with the action of the story.

4. The setting is one you would find in everyday life. There are no spectacular scenes in regards to elaborate castles or upper-class niceties. The settings are typically set in lower-class homes and workplaces.

As for the play "A Streetcar Named Desire", there are many different aspects of Naturalism depicted in the play.

Scene One: First and foremost, the scenery of the play depicts the ordinary. Elysian Fields is described as ordinary and poor. The buildings are described as "raffish".  The characters of the play also support typical Naturalistic characterizations. The men are blue collar workers and the women deal with abuse. Three times throughout the play domestic violence and rape is depicted. (These show the assumed lower class actions of the people who live here.)  The setting is also set by the music of the lone blue piano. The piano sets the mod for the entire play- one of solitude and depression.

Scene Two: This scene offers another aspect typical of Naturalistic literature. Stanley comes to find himself in circumstances beyond his control- Stella has invited her sister to stay with them. Given that Stanley is not happy about this, he does come to find out that Belle Reve has been sold- he, wanting to find a way to make this situation better, believes that getting money from the sale would make his life more bearable. Unfortunately, like all Naturalistic literature, this is not the outcome of the piece. Instead, there is no money and Stanley decides to take something else from Blanche by raping her- what is left of her sanity.

This being said, Williams is not typically depicted as a Naturalistic writer. He is normally placed in either the Modern or Post-Modern periods. Regardless, "A Streetcar Named Desire" does hold typical Naturalistic characteristics throughout the play.

See Historical Context link for importance of scenery.

See Style link for importance of motifs.