The poem has a number of themes underlying the story. The themes of loneliness and silence, beauty and mystery of the natural world and the social stratification or class are the prominent ones I can find here.

The speaker is alone with his horse and doesn’t meet anyone on the way. Even the owner of the woods live far from there. So he is an isolated wanderer in that sense. Moreover, silence prevails everywhere. The narrator can only hear the sounds of the harness bells of his horse and the ‘downy flake’.

The natural scenery that the poet has depicted in the poem brings a sense of mystery. The woods covered with snow is beautiful. So the speaker stands there to enjoy it. But the silence, the darkness, the deep woods — all are mingled to create a mystical atmosphere.

The social position or class of the narrator is revealed more than once in the poem Stopping by Woods on a Snowy Evening. The narrator feels easy or comfortable thinking that the owner of the woods won’t see him stopping there, suggesting his lower social status. Moreover, he cannot afford to buy a good horse, as suggested in the words ‘my little horse…’. And last but not the least, as the last stanza suggests, the speaker can’t afford to spend some more time enjoying the beauty of nature, as he has to work hard to earn his living.