Matt Ladner does a good job of explaining how his beliefs shape his education policy recommendations. It’s a quality that he shares with Horace Mann, who persuaded the people of Massachusetts to adopt a fully tax-funded state school system based on his own beliefs about how a just society should educate its children.

More than a century and a half later, we are still struggling to replace Mann’s unresponsive, divisive, ineffective, wasteful, and often cruel system with one that actually works. So, as we reflect on exactly what to replace Mann’s system with, we have to ask: how did he get it so very, very wrong, and how can we avoid the same fate?

I suggest that Mann’s great mistake was to base his policy recommendations on his belief system. To avoid sentencing future generations to a similarly dysfunctional education, we must base our conclusions on a broad and systematic analysis of the evidence. We should study school systems historically and internationally to understand what works, what doesn’t, and why. We should make predictions about how different policies will unfold and then try to test those predictions empirically. We should observe how different policies play out across states rather than rushing to homogenize them before their effects can be compared.

At least that seems to me our greatest hope of avoiding Mann’s tragic mistake. And if the policy conclusions we reach do not happen to be the easiest to implement, we can take comfort in the fact that Mann succeeded in promoting a system that had no basis in reason or evidence despite strong and longstanding opposition. If a radical bad idea could triumph, why not a radical good one?