What commentary does Marlow offer on the issue of "restraint"? What accounts for the restraint shown by the natives, and what accounts for the restraint shown by the Manager?

The inferiority of the natives is a constant theme. About the fireman on his ship, Marlow remarks "he was there below me ... to look at him was as edifying as seeing a dog in a parody of breeches." The lower physical position of the body corresponds to a mental and social state. The narrator participates in believing what he describes is the inherent inferiority of the blacks. In all possible aspects they appear subservient to the white men, and even seeing them wear pants amounts to no more than a warped joke. The one time that a native actually speaks is when the ship approaches the brush, right before the attack, and all he has to say is that any prisoners should be given to the crew as a meal. The narrator cannot understand why the white men were not eaten. He cannot credit the blacks with intelligence beyond instinct. During the battle, one native is shot, with Marlow and the Manager watching: "I declare it looked as though he would presently put to us some question in an understandable language, but he died without uttering a sound." For him there is no comprehension of the blacks he encounters. They are always evaluated and silenced, it seems, before they can speak. Nevertheless, Marlow does feel a real kinship to his "savage" crew, which places him above other whites in the narrative. Even here, though, he has shortcomings—his appreciation of the helmsman after he has died, for instance, seems more machine-like than humane.