The poem, technically, contains one character: the speaker, who directly addresses the reader and narrates the events of the poem. However, the speaker barely appears in "A World Made by Atoms." There are no instances of the first person singular, only of the first person plural, as in "we build" (5). The speaker never speaks for themself, only for humanity as a group, and without providing any details about who they are or what sort of person they might be. By having such a minimal role for the speaker, the poem allows the philosophical ideas to speak for themselves.