This complex novel is indeed rich in symbolism. Some of the major symbols include these:
- The Congo River: It is the river that takes Marlow deep into the African continent, carrying him away from civilization and into ever darker regions of an uninhabited wilderness. The river acts as a stream of consciousness as Marlow makes not only a physical journey but a psychological journey, as well. As he travels into the primitive Congo, he also travels into the unknown wilderness of his own psyche.
- Kurtz: In his brutal, self-obsessed state, Kurtz can be interpreted as a symbol of Sigmund Freud's id, the part of the human psyche that is most elemental, where instinct and primitive human impulses live. The id is not subject to conscience or social restraints, just as Kurtz's behavior is not held in check by any moral or social codes of behavior.
- The fence of human heads: This is a powerful symbol of Kurtz'sdescent into depravity; it symbolizes how completely isolated he has become from humanity.
- Ivory: The European traders' insatiable demand for ivory and their horrible, inhuman activities undertaken in pursuit of it make ivory a symbol of naked greed.
- The candle: As Kurtz lies dying aboard ship, Marlow goes to him carrying a candle. The candle can be interpreted as a symbol of Marlow's humanity. He despises the evil that Kurtz represents and the suffering he has imposed upon the natives, but Marlow finds compassion in himself for the dying man. The light of Marlow's candle contrasts the darkness of Kurtz's inhumanity and depravity.
There are many other symbols throughout the novel, but these five play an important role in developing Conrad's primary themes.