The speaker, as we discover in the last stanza, is a military instructor (“late in school”); the “you” can be the reader, an unspecified person who might be present, or humanity in general. The diction of the first three stanzas is general and abstract. The speaker asks unanswerable questions: Why does humanity continue to wage war? Why doesn’t God put a stop to it? Is humanity stupid? Is God indifferent? Is warfare the only “eternal truth”? In the last stanza, the speaker shifts to specific and concrete terms and names: Van Wettering, Averill, list, lever, pawl. He also shifts from abstract considerations (”infinite space,” “eternal truth”) to specific facts: the names of young soldiers who have “gone to early death” (notice the ironic contrast between the “early death” and “late in school”). This shift does not answer the earlier questions, but it does focus the poem and bring it to an effective conclusion. The jargon referring to firearms in this closing stanza works perfectly; it provides the concreteness of objects and weaponry even if we ourselves do not have the technical knowledge to identify the objects.