Beginning with the title and opening line, darkness is present throughout the poem in all its manifestations as its central motif. From the start, it is clear the speaker is “accustomed” to this darkness (Line 1); it is with them always and no longer seems as frightening as it once did. In the second stanza, the speaker describes how the night is at first new and unsettling, but then we “fit our Vision to the Dark” (Line 7)—in other words, we adjust ourselves to the new reality of living in darkness.

In these first two stanzas, darkness is presented as literal. When presented with darkness, one’s eyes adjust and continue moving forward. The third stanza, however, parallels this darkness with darkness of another kind: “And so of larger — Darknesses — / Those Evenings of the Brain” (Line 9-10). Here, the darkness becomes internal. During this time there is no moon or stars to extend their guidance, which makes this darkness of a very different persuasion. Unlike external darkness, internal darkness can only be broken from within. The poem details the obstacles that even the bravest people can encounter when finding their way through this darkness; in the end, however, “the Darkness alters” (Line 17) as the speaker finds clarity and strength.