Stare decisis is the legal principle which binds courts to follow precedent, retrace the footsteps of other judges' decisions. As someone previously condemned to an Orthodox Jewish education, where I gritted my teeth at the idea that medieval rabbis would always be wiser than modern rabbis, I completely missed the rationale for stare decisis. I thought it was about respect for the past.

But shouldn't we presume that, in the presence of science, judges closer to the future will know more—have new facts at their fingertips—which enable them to make better decisions? Imagine if engineers respected the decisions of past engineers, not as a source of good suggestions, but as a binding precedent!—That was my original reaction. The standard rationale behind stare decisis came as a shock of revelation to me; it considerably increased my respect for the whole legal system.

This rationale is jurisprudence constante: The legal system must above all be predictable, so that people can execute contracts or choose behaviors knowing the legal implications.

Judges are not necessarily there to optimize, like an engineer. The purpose of law is not to make the world perfect. The law is there to provide a predictable environment in which people can optimize their ownfutures.

I was amazed at how a principle that at first glance seemed so completely Luddite, could have such an Enlightenment rationale. It was a "shock of creativity"—a solution that ranked high in my preference ordering and low in my search ordering, a solution that violated my previous surface generalizations. "Respect the past just because it's the past" would not have easily occurred to me as a good solution for anything.

There's a peer commentary in Evolutionary Origins of Morality which notes in passing that "other things being equal, organisms will choose to reward themselves over being rewarded by caretaking organisms". It's cited as the Premack principle, but the actual Premack principle looks to be something quite different, so I don't know if this is a bogus result, a misremembered citation, or a nonobvious derivation. If true, it's definitely interesting from a fun-theoretic perspective.

Optimization is the ability to squeeze the future into regions high in your preference ordering. Living by my own strength, means squeezing my own future—n...

Fun Theory

Fun Theory