Two hundred years is a long time to bang your head against a wall. When it comes to school reform, though, that’s what we seem to do. I’m just back from an archive trip in Philadelphia and I’m spooked by the parallels between school-reform mistakes back then and those pointed out just this week by a savvy teacher in New York.

The New York teacher, Emily Kaplan, tells a story any experienced teacher can relate to. She studied at a great university, learned all she could about children and teaching. When she got to her first classroom, she immediately ran into a situation she had never prepared for: One of her students just wouldn’t/couldn’t stop farting. It’s funny, but it’s more than funny, too. As Kaplan puts it, most of our big-picture ed-reform plans are made for “theoretical children.” As she explains,

Theoretical children are useful: they are predictable, generalizable. They lend themselves easily to an agenda; nothing they do is inexplicable. Their development is linear, their roadblocks routine. They exist neatly in quantified data; they are easily essentialized. Theoretical children don’t cry for no reason, they don’t laugh out of turn; theoretical children certainly don’t fart.

Theoretical children are discussed often by scholars and policymakers, but theoretical children don’t populate our classrooms— because theoretical children don’t exist.

Kaplan is right on. Every real teacher knows that plans need to be held lightly; theories need to be embraced tentatively. As I’m learning in my new research, the effort by experts to change schools based on what children theoretically will do has always plagued our school-reformm dreams.

Last week I began the archival grunt work for my new book. I’m exploring the school-reform plans of Joseph Lancaster and his devotees. Two hundred years ago, nearly exactly, the Pennsylvania legislature passed a law mandating Lancaster-style schools for Philadelphia. Why were the lawmakers so excited about this educational plan?

Nothing can go wrong if the system is right.

In large part, Lancaster convinced politicians that he had figured out a perfect system. He pitched a school set-up that would deliver cheap, effective literacy, numeracy, punctuality, and nondenominational Protestantism to poor children. In 1803, for example, he published his flawless system, a system built on the actions of “theoretical children.”

As Lancaster explained, school discipline had long been a problem, but he had solved it. He outlined at painful length and detail the way he had supervising boys—“monitors”—track the behavior of their fellows. Students who misbehaved would have logs tied around their necks. They would be shackled together with other miscreants. If that didn’t work, they might be

put in a sack, or in a basket, suspended to the roof of the school, in the sight of all the pupils, who frequently smile at the birds in the cage.

Lancaster didn’t like shaming his students this way, but he thought it was the perfect solution. As he explained, when the misbehaving student

Finds how easily his punishments are repeated—that he himself is made the instrument—and no respite or comfort for him, but by behaving well, it is more than probable he will change for the better.

In theory, the plan was perfect. In theory, anyone could follow the simple steps laid out for good student behavior. In theory, students responded well to Lancaster’s machinations.

Guess what—it didn’t work. As Emily Kaplan points out, children don’t exist only in theory. They fart. They rebel. And sometimes, if you tie a log around their neck or hang them in a birdcage, they don’t respond well.