Robert Frost himself was reticent to condone much deep analysis for such poems as "Stopping by Woods on a Snowy Evening," which perhaps indicates that he intended the work in its simplicity to be accepted "as is," with a sort of trust or faith that it means exactly what it says: a single moment out of time, a snowy evening illustrated by words. Yet there are themes present in the work, whether or not Frost intended for them to be analyzed or included at all.

Humans Versus Nature

The theme of humans versus nature is quite common in many of Frost's poems. He seemed especially taken with crafting a lovely natural scene—organic, untouched, unaffected—and then introducing an external force, often a person or a man-made structure, like a cabin or a path. Even poems that seem to focus solely on the untouched natural world have an intruder of sorts in their midst: that is, the speaker, who describes the scene in the first place.

In "Stopping by Woods," the speaker and his horse pause at the edge of a wooded area that belongs to someone the narrator knows, and from the first line of the poem, humans and nature are in conflict: "Whose woods" (line 1) juxtaposes the tension between, on the one hand, a natural place, this forested area that perhaps should not be owned or overseen by anyone—and on the other hand, the indication that this acreage is, in fact, owned. That the narrator himself with his horse (and, one presumes, whatever vehicle to which the horse is harnessed, such as a carriage or a sleigh) is an intrusion into the otherwise idyllic dark, snowy scene is another contrast, another tension made tangible.

Desire Versus Obligation

The narrator describes the woods with careful attention to detail: watching the woods "fill up with snow" (line 4) and the soft impressions of sounds, "of easy wind and downy flake" (line 12), where there is otherwise only the preternatural stillness of the natural world thus far, untouched by movement or noise from an outside force. That the narrator is so clear and delicate in his description underscores the longing he feels toward visiting the woods, the desire he has to remain watching or even to explore that which is "lovely, dark and deep" (line 13).

And yet, in the very next line, the paradox is revealed: He wishes to remain, but he has

promises to keep,
And miles to go before I sleep. (lines 14–16)

Here is a pull to which anyone can easily relate: the daydream versus the real world, play versus work, fun versus duty. There is real want in the fact that the sight of the woods has pulled the man to a stop at all—and still he goes on, denying his want, out of loyalty to a different value.

Secrets

Promises are not the only things that one keeps. Secrets, both implicit and explicit, are another. And there is something secretive, some uncertain thread in the tone of the poem: the narrator thinks he knows to whom the woods belong (line 1); he has stopped somewhat clandestinely just beyond the border of the other man's woods, even to the surprise of his (the narrator's) horse, who is quite probably used to going right onward, home for feed and warmth (lines 3, 5, 9–10); this is, it turns out, "the darkest evening of the year" (line 8), which comes with its own mystery.

It is almost as though the narrator had something on his mind when he paused by the woods, something about which he is deep in thought that he does not clearly delineate to the reader (except for the final stanza about keeping promises and miles yet to go) but that weighs enough on him to draw him to a dazed halt at the edge of these woods. Even the final lines, repeated—"And miles to go before I sleep" (lines 15–16)—are full of secret possibility: Are the miles to which he refers literal geographical miles, in terms of an actual distance? Or perhaps milestones in some venture or relationship that he needs to meet? Or psychological miles, maybe, and much more to think about before he makes a decision?