Recall that the speaker in "Mending Wall" questions his neighbor's stolid assumption that "good fences make good neighbors." What he objects to is not so much the sentiment itself as the unwillingness or inability of the other to think for himself, to "go beyond his father's saying." Just so; we must try to get beyond the apophthegm-like opening line of "Mending Wall," testing carefully for gradations of tone as we proceed. Is it the proverb-like authority of "something there is . . . " that makes it so natural to equate "something" with the speaker? Once this equation has been made, the reader joins the speaker in sympathizing with this mysterious "something" and hence in opposing the neighbor's unthinking defense of walls.
Frost rings subtly drastic changes on the sound of a phrase like "good fences make good neighbors." By the time the poem ends, this line has acquired some of the pat stupidity of a slogan. Similar turns of the screw affect the opening line, when to it is added the darker phrase "that wants it down" and again when the speaker refuses to name the antiwall "something." "Elves" is the closest he gets, yet "It's not elves exactly, and I'd rather / He said it for himself." Elves may mean not willowy things out of Tolkien but darker forces of the wood, for the next image is one of darkness. The neighbor is viewed as subtly menacing, "an old-stone savage armed." Yet this man has been the one to defend boundaries. The apparently relaxed and leisurely pace of the poem has made us lower our own boundaries and forget who is on what side.
At any rate, although the speaker's ironic evasiveness undermines any confident interpretation, Poirier is surely right when he makes the following point:
. . . .it is not the neighbor . . . a man who can only dully repeat "good fences make good neighbors"-- . . .it is not he who initiates the fence-making. Rather it is the far more spirited, lively, and "mischievous" speaker of the poem. While admitting that they do not need the wall, it is he who each year "lets my neighbor know beyond the hill" that it is time to do the job anyway, and who will go out alone to fill the gaps made in the wall by hunters. . . . Though the speaker may or may not think that good neighbors are made by good fences, it is abundantly clear that he likes the yearly ritual, the yearly "outdoor game" by which fences are Because if fences do not make good neighbors the making of fences can.
Part of an old-fashioned neighborliness which results from the annual wall mending is fellowship, the potential exchange of feelings and ideas. More salient still is the joint maintenance of form for its own sake, not for utility, so that wall-making also becomes "a time to talk."
At the same time, repairing the wall means renewing that structure protective of "infant industries" or "a mood apart," protective from trespass on a symbolic level, even if "My apple trees will never get across / And eat the cones under his pines." As an occasion for craft, besides being a guarantee of privacy, the wall is also crucial. Frost often compared free verse to playing tennis without the net--a remark which no one has ever interpreted as an attack on nets.