"Light" is used in the title of the novel and chiefly related with Lena throughout the novel. As for Lena's connection with "light," though, AndrŽ Bleikasten has already given a thorough treatment, which leaves little to add.
    "Light" is an opposite idea to "dark(ness)." While "dark(ness)" is associated with "Black" or "Female" in the novel, "light" is a symbol of "White" or "Male." The phrase "the lightless hot wet primogenitive Female," (115) a metaphor for the air in the Freedman Town, the Black-populated district in Jefferson, is its typical illustration. It explicitly shows the relationship among "dark(ness)," "Black" and "Female," and thus implies the connection of "light" with "White" or "Male."
     However, there is another significance of "light" which has been neglected: "the promise of home." One example is when McEachern first brings Joe to his farm. He points up a single "light" shown in the dusk, and says to his adopted son , "Home." (143). Another is when "light" implies the destination of Joe's escape from the McEacherns. After he knocks down McEachern and robs his adoptive mother, he rushes toward the only light shown in the dark to marry Bobbie. Though in these instances the promise of "home" is never fulfilled, this implication of "light" is unmistakable.
     While the importance of "light" is implied in the title of the novel, its tentative first title "The Dark House" definitely imprints the significance of "dark(ness)" on the novel. That it implies the link "Night - Black - Sexuality" or "Mother - Female - Earth" has long been a critical agreement. Besides, just as "light" is a symbol of Lena, "dark(ness)" is inseparable with other two protagonists in the novel: Joe Christmas and Gail Hightower.
     Joe Christmas is associated with "shadow," a variant of "dark(ness)." Since "shadow" is "darkness" upon "white" projected by "light," it is quite suitable for the person who, suspended between Black and White, is finally killed and castrated as a "nigger" by a white supremacist.
     "Dark(ness)" is the word for Gail Hightower. His stagnant house is another "dark house" in the novel. The image of his sitting in the dark window watching out the street is an apt symbol of his timid existence. At the end of the novel he sums up his life in a cry, "I have been a single instant of darkness in which a horse galloped and a gun crashed" (491) So far we have generally surveyed the significances of "light" and "dark(ness)." In the following we will take two scenes from the sequence of Joe's affair with Joanna and try to show the dynamic workings of rhetoric in Light in August.

     The first scene to examine is where Joe lies hiding under the shrubbery waiting the time to enter Joanna's house.
    Lying in a tangle of shrubbery a hundred yards from the house, Christmas heard a far clock strike nine and then ten. Before him the house bulked square and huge from its mass of trees. There was a light in one window upstairs. The shades were not drawn and he could see that the light was a kerosene lamp, and now and then he saw through the window the shadow of a moving person cross the further wall. But he never saw a person at all. After a while the light went out. (228)

     First, the shrubbery under which Joe lies is where Joanna waits for Joe burning with desire in the second phase of their affair. It is the locus of eros symbolizing Female sexuality. That Joe lies there before he enters her household anticipates his entrapment by Joanna's sexuality. It is the same place where he waits the time for their last confrontation, which affirms the relationship between sexuality and death in this novel.
     Secondly, Joanna's house is another "dark house" in the novel. This is the place of her birth and death, and a symbol of her body. It also symbolizes a heritage from her father, the most influential of which is his view of the Black as "curse upon the White." However, it use to be a plantation house, built upon the exploitation of slaves, and thus implies a heritage of racism in the South. These complicated implications make this house an apt symbol of Joanna, a daughter of a New England Abolitionist, who devotes her life to "lift" the Black and at the same time consumes herself with the belief that they are curse upon the White.
     The most suggestive part in the quotation above, however, is that concerning with the "light" in the window.
     As is mentioned above, one of the significances of "light" in this novel is "the promise of home." This is another instance: it is apparent that the "light" Joe sees in the window suggests "home," for he is now attempting to break into the house to get some food. Food in this novel is inseparable with "home" (the case of Mrs McEachern) and sex (the cases of the dietitian and Bobbie.) As for Joanna, she is source of food in the beginning of their affair and then becomes a kind of wife for him. Thus with Joanna Joe experiences what "home" he can get in his life. The light he sees in the quotation above anticipates that "home" for him.
     However, it is not "home" only that the light signifies here. It is the light of kerosene lamp, the hot suffocating light and smell of which is always associated with the life of the Black throughout the novel. Therefore, the light he sees in Joanna's room implies both "home" he yearns for and the Black life he fears all his life. Thus the "light" has contradictory significances : it is the object of desire and hatred at once.
     At the end of the quoted scene, the light in Joanna's room goes out. That may imply that here again the promise of "home" will not be fulfilled for Joe. There is another implication, though: it anticipates the Joanna's death at the end of their affair. Actually, the scene of their last confrontation apparently corresponds with the one examined so far. Then we have to quote and analyze the scene to see the dynamic rhetoric in Light in August.