Though sunlight symbolizes disillusion, there is a second kind of light in Nostromo, seldom seen, associated with the subjective soul. Compare the distinction made by the narrator when describing Decoud's letter, between the limited "light of investigation" and the light which conveys "a correct impression of the feelings." It is this latter kind of light which lends the symbolic title to Part Three of the novel.

Note that the narrative calls attention again to the "deep shade" and even the prettifying "half-light" characteristic of the dream-ideal. The lighting symbolizes Mrs Gould's new "faith" in the "good heart," i.e., the ideal of the worthy subjective soul.