A long time ago in a movie studio far, far away, a man named George Lucas assembled a giant cake called Star Wars—a rickety thing, looking as though at any moment its three tiers would collapse upon themselves. Tasty, though: You had to give him that. And maybe sturdier than it originally looked, since the foundation survived, more or less intact, Lucas’s attempts to stack three more layers on top, 20 years later.

While the Star Wars movies were making their long, $30 billion run at the top of popular American entertainment, a man named Cass Sunstein was off at the University of Chicago and Harvard, teaching and gathering wisdom in a kind of law professor’s version of Yoda in the distant Dagobah system.