What does Frost mean by "good fences make good neighbours"?

It's an idiom. It means that the best way to stay friendly with your neighbours is to build a fence. Literally setting boundaries. It will be easier to remain cordial if there is a clear demarcation. Draw a line. This is "my house/property", that is "your house/property" - that is agreed, so we won't need to argue about it. It can be figurative. Before a road-trip, we agree that you're the driver, I'm the navigator. I won't tell you how to drive, you won't tell me how to read the map. That will prevent arguments.

What it means literally is that if you have a strong fence around your property that your neighbor cannot cross, this means that your neighbor will never come into your property. This means your neighbor will not bother you and you and your neighbor will get along well. What it means metaphorically is that when you and another person have healthy boundaries in your relationship, then you And the other person will have a good relationship

It's basically a polite way of suggesting that your neighbours have no right to invade your privacy or tell you what to do on your own property, and that people will get along better if they respect those boundaries.

As a matter of what the saying means, it literally means that if you have clearly delineated the boundary between your property and your neighbor's, you will never quarrel. More figuratively it means that if you stay out of someone else's affairs and they stay out of theirs, you will have have a good relationship. I have to disagree with the other redditors who are saying this is a positive or good thing, though, particularly in the context of Robert Frost's excellent poem "Mending Wall." The poem rejects the idea that "good fences make good neighbors"! That is the whole point of the poem!

In addition to what others have said, it also implies that both you and your neighbours need to each be responsible for the upkeep/maintenance of your side of the fence/relationship and not let it deteriorate (literally or figuratively). In other words, if you are always making an effort but they do not, the fence/relationship is no longer good and you may feel some resentment. This also connects back to having boundaries because no matter how they let their side fall behind, it is not your job to fix.

In British English, a fence is commonly used slang for a person who buys and sells stolen goods. Which can lead to a joke meaning of the phrase. So that having a fence as a neighbour means you can buy and sell an items that may not be legally owned. This leads to the idiom "Fell off the back of a lorry," in which you admit you have something in your possession that isn't legal. A lorry generally means a small rigid-body vehicle such as a Fuso brand truck. I don't think the word is used in American English, I'm not sure about other branches of English.

Respect boundaries is important.

Establish boundaries, basically.

I want to note that there's a slight ambiguity to this phrase that gives it just a bit of extra spice, both of these are valid readings: * Good fences *create* good neighbors. (good fences can make a bad neighbor into a good neighbor) * Good fences make *for* good neighbors. (with a good enough fence, you won't even see your neighbors, the fence becomes the neighbor) It's a contrast between "we'll get along better if we don't bother each other" and "I'm antisocial, and didn't want to have neighbors in the first place." I think Frost phrased it this way on purpose, he's implying that the person he's talking about means the first, but Frost himself means the second.

He means the inanimate object "the fence" when it's good (large , solid and structurally sound) that it the fence itself is the good neighbour and regardless of the people on the other side.

To add to what others have said, the expression (or a variant) had been around for over 200 years before it appeared in Frost's "Mending Walls." The Oxford Dictionary of Quotations has the earliest version from a letter by E. Rogers from 1640: "A good fence helpeth to keepe peace between neighbours; but let vs take heed that we make not a high stone wall, to keepe vs from meeting."

I think it’s also worth noting that in the poem, Frost and his neighbor were walking the fence line together, repairing the wall, and cooperating in a neighborly way. The neighbor's comment seems to mean "having a strong barrier between us is good," but at the same time they’re completing a project together. Personally, I find that ironic.

It is about respecting each other's boundaries, which includes other types and not just the physical ones. It applies equally to the boundaries of others as well as to one's own. Mending a boundary that has been breached is a vital step in restoring harmony and good relationships.

literally that, good strong fences improve your relationship with your neighbors

It means that having boundaries, sometimes even physical ones, can improve the respect and friendliness between people