'Why do they make good neighbors? Isn't it Where there are cows? But here there are no cows. Before I built a wall I’d ask to know What I was walling in or walling out, And to whom I was like to give offense. Something there is that doesn’t love a wall, That wants it down." I could say, "Elves" to him
Our speaker wants to know why good fences make good neighbors.
Are fences and walls good because they keep the peace between neighbors by ensuring that neither property is destroyed? If so, what could possibly destroy pine trees and apple orchards?
The speaker understands the neighbor’s philosophy, if one person has cows and wants to keep the cows from wrecking havoc. BUT, THERE ARE NO COWS (we wish there were).
Our speaker gets a little saucy at this moment, and we infer that the wall was never his idea – his neighbor built the wall.
The speaker puts on his "judgmental" hat and tells us that, if he ever builds a wall, he will first ask himself why he’s building the wall and what that wall’s purpose is.
For example, is the wall’s purpose to keep cows at bay, or to keep them from escaping? Will he mean the wall to discourage visitors, or to keep small children from wandering into the street?
Our speaker also tells us that, if he ever is to build a wall (which, at this point, we’re pretty sure he never will), he will first ask himself whether such a wall will offend anyone.
Indeed, our speaker’s feathers are ruffled.
Does anyone catch the pun in "offense?" Get it? "Offense" sounds like "a fence." Hehe.