With the title of Part Three, Conrad completes contruction of the massive symbol that dominates the end of the novel. The silver, which titled Part One, has now been moved to the Isabel, which titled Part Two. The climax is the titular lighthouse which is built on top of them in Chapter 3-12.

Symbolically, the silver represents the dream-ideal, while the Isabels represent individual souls isolated in the gulf of subjectivity. The movement of the silver to the "Great" Isabel stands, I believe, for a historical progression: the transfer of ideals away from mass social crusades, to the new modern ideal of subjective individual self-fulfilment. It is fitting that the transfer was made by Nostromo and Decoud, two characters who resist in their own ways the destructive dream-ideals of history. The new ideal of the individual soul is one that Nostromo celebrates throughout in the form of "character," the unique and valuable personality, the only saving grace of that subjectivity which isolates us and causes political tragedy. What remains for Part Three is the lighthouse, which dramatically evokes the solitary soul reaching out into the darkness. Literarily, the lighthouse represents the novel itself -- the attempt to communicate truth and feeling across the subjective gulf. Politically, it represents the dream of a society founded on compassion for the inner soul, the final transcending of the cycle of conquest and revolution. In the pessimistic night of Nostromo's worldview it is, to use Mr Gould Sr's phrase, the "ray of hope."

Part Three opens with the anarchy of disunity, then shows society knitting itself back together after the long night of Separatism and disillusionment. The dream-ideal of Unity must be reestablished; the alternative is not only social chaos but an "utter scepticism" whose consequences are graphically illustrated by the suicide of Decoud. But it can only be reestablished as a suffocating fiction, demonstrated through the device of Captain Mitchell's pompous tour-guide narrative in the modern Sulaco. Part Three, however, is mostly Nostromo's story, and through him the story of the laboring class' turn to socialism. He awakens a changed man, disillusioned with his previous fidelity to the rulers and newly class-conscious. Though he pretends to return to his old fidelity, in reality he secretly keeps the cache of silver for purposes of personal gain and "vengeance." This arrangement symbolizes the socialist consciousness, in which the People continue to labor for the exploitative society without loyalty to it, the while nurturing secret dreams of vengeance and liberation.

The novel reaches an epic crescendo with the masterful drama of Nostromo seeking marriage, an allegorical tale that represents mankind seeking a "state" of love. That utopian state, transcending conquest and property, is represented by Giselle, but Nostromo can only yearn for her while maintaining a sham engagement to Linda, reflecting the People's sham allegiance to the exploiting society. Torn between illicit love and illicit wealth, tragically seeking to combine them (into the utopian vision), he meets his end in a case of mistaken identity, but the People live on in a "cry of undying passion" from the lighthouse tower.