The Unionist Garibaldi would indeed look dimly at Decoud's skepticism, which has
led to the Separatist movement now going on. Conrad is establishing the dark night
here in preparation for Decoud and Nostromo's voyage, but it also has a symbolic
meaning: the darkness of the Placid Gulf represents the space between souls, and
Separatism, by emphasizing the differences between subjective natures,
brings this darkness to the forefront.