Monygham's condemnation of the material interests is a key passage in the novel, and is meant to stand in opposition to Charles Gould's classic defense. He admits that the material interests do exactly what Charles Gould said they would: they establish law and justice. But it is "their law" and "their justice," meaning on one level the self-serving law of a ruling class, and on another level the kind of natural law that governs inanimate "material," and which has no bearing on the necessities of the human soul. In this latter sense the material interests are "inhuman." Their motive of "expediency" says nothing about what they are expedient in the service of; in other words the material interests as such lack "rectitude" and "a moral principle."

Note that Monygham makes no claim that rectitude and moral principles are beneficial; he merely says that they are human. The tumultuous, oppressive Costaguana over the border is an example of a human society that in his view can only be remedied by the application of the material interests. In his cynical outlook, which speaks for the novel, there can be no society that is at once lawful, just and human.