Yon and Snare

Yon shows the too-small edge. She flies over the shared clover patch where five rabbits graze, and drops a string-loop around just one rabbit. "Watch how this one thinks," she says. "Its circle is itself. Inside that circle, the smart move is obvious: take a little more clover. One rabbit's extra bite won't hurt the whole patch — and it's true, inside this small circle." She drops identical loops around each of the other four. "But look — every rabbit has drawn the same tiny circle, around itself. Five little circles, and the shared clover patch sits in the middle of all of them, belonging to none of the circles." She lifts all five loops and draws one big circle around the whole patch and all five rabbits together. "This is the edge nobody drew. The one that includes the shared thing itself. As long as each animal's map ends at its own nose, the patch in the middle is invisible — and a thing nobody sees is a thing everybody eats."

Snare shows the trap that springs. She sets the five rabbits grazing and lets it run. Each rabbit, sensibly, takes a little extra — each acting only inside its own small circle. The clover thins. Thins more. Then it's gone, cropped to bare dirt, and every rabbit — including the one that grabbed the most — sits hungry. "There's the trap," Snare says. "And notice: no rabbit did anything wrong by itself. Each one made the smart move for its own little circle. The trap wasn't in any rabbit. It was in the shape — many animals, one shared thing, every edge drawn too small." She coils her untangling-wire. "This shape has a name, and it's everywhere: a shared clover patch, a shared pond, a shared quiet, a shared sky. Anytime the thing that matters sits outside everyone's private circle, this trap is waiting to spring."

Then the two of them showed, together, the thing neither could show alone: that the fix for the trap is exactly the fix for the boundary — and you need both to see it. A class stood around a shared-pasture game, each kid herding a little flock onto one green field, each kid scored only on their own fat sheep. Snare narrated the trap: each kid, sensibly, put on one more sheep — good for their score. Yon narrated the edge: each kid's circle was drawn around only their own flock and their own score. And so — reasonable move by reasonable move — the field was grazed to mud, and every flock, on every kid's tiny map, went hungry. "I lost!" Pip said. "But I only ever did the smart thing!" "You did the smart thing for your circle," Yon said. "And your circle was too small." "Which sprang the trap," Snare said. "Now — let's fix it, and you'll see the two halves are one." They reset the game. First Yon had each kid redraw the edge: "Draw your circle around the whole field, not just your flock — the field is on everyone's map now." Then Snare had them name the trap out loud and agree: "We're in the commons shape. Everyone puts on a little less, so the grass regrows, so we all keep grazing forever." And with the wider edge and the named trap, the kids held back — the field stayed green, and every flock grazed steadily, turn after turn, better off than before. "See how it took both of us?" Yon said. "Widening the edge without naming the trap, they'd have seen the whole field and still raced to grab it." "And naming the trap without widening the edge," Snare said, "they'd have known the shape but each still be staring at their own nose, unable to see the shared thing." Pip looked at the green field. "So the boundary and the trap are the same problem." "Two heights of one thing," Yon said. "I see it from above — the circle's too small. Snare sees it from inside — the trap it springs. You need the view from both."