"Acquainted with the Night"-Robert Frost

In "Acquainted with the Night", Robert Frost sets an extremely depressing tone.  The setting of the poem is the nighttime, and the diction makes the imagery all the more discouraging.  There is an overwhelming sense of isolation.  The speaker never interacts in any dialogue and even avoids eye contact with others.  

"I have passed by the watchman on his beat

And dropped my eyes, unwilling to explain." (Frost, 976)

To the speaker, there exists no division between right and wrong.  Or, at the very least, he fails to perceive it.  In his world, humanity as approached a glass ceiling and can progress no further.  Therefore, they fall into a cycle.  Some men do horrible things, while other sit back and watch.  They are the silent observers of destruction.  The speaker claims he has been both.  In this moral -lacking world, the speaker can express only loneliness and despair, because that is all that exists.  Due to the cyclical nature the poem is structured in, the speaker appears to be saying that is how it will always exist as well.