Farmer's most important technique in this novel is the use of an intricate network of contrasting images, colors, and symbols to reinforce his thematic insistence on the acceptance of dualities. The novel associates "good" with heat and light, "evil" with cold and darkness. For example, Mother Boonta's temple includes seven candles and a flaming sword, and the six fathers of Yess speak in terms of light and warmth. Conversely, when the six fathers of the evil Algul try to convert Carmody, they image ecstasy for him in terms of darkness and the coldness of space. Farmer also uses contrasting colors to suggest dualism: Red symbolizes passion, sexuality, and birth, as is illustrated by the red floors, walls, and curtains of Boonta's womblike temple; green symbolizes rationality and technology, as is shown by the color of the fountain pens, space-ship interiors, and officers' uniforms.

Perhaps the most important cluster...