On open hillside above the trees, where there’s no path to speak of, you sometimes find a small pile of stones. A cairn. It has no author you could name and no single moment of building. Somebody put a stone down, and the next person who passed put another on top, and the pile grew a little taller than the weather could knock down.

What I like is how little each person has to do. Nobody who adds a stone knows the route’s whole history, or who started it, or where it leads for anyone but themselves. They only know that someone before them thought this was the way, and that they were glad of it. So they add one stone. That’s the entire contribution, and it’s enough, because the next walker will see a pile slightly more obvious than it was before and will walk a little more confidently.

It works only because the stones are all the same kind of message. Nobody writes an essay on the cairn. Nobody argues about it. The thing that gets passed along is “this way, someone checked,” and every stone repeats it without changing it.

There’s a code of manners that goes with this, which I find touching. You don’t build new cairns where there’s no route: a pile that points nowhere sends people confidently the wrong way, and fog makes that dangerous. You add to the ones that are honest, and in some places people quietly knock down the ones that aren’t. The pile is only worth trusting while everyone treats it as a promise.

Whoever left the first stone will never know how many people it helped. That seems fine to me. Most of what carries us along was set down that way, by someone who just wanted the next person to have an easier time.