The written word is the most underappreciated constraint on arbitrary government. Our written Constitution provides for how we are ruled and limits the powers of our rulers. Our statutes define the duties of the ruled and create still additional rights for the benefit of the ruled. But little of either would matter much if judges weren’t compelled to write down the reasons for their decisions, publish them for all the world to interrogate, and in doing so explain how those decisions are consistent with, even compelled by, past decisions recorded for the same purpose. It is rule not by passion or caprice, but by reason. And at its best, it is the closest thing to philosophic rule the world has known.