[vinceguidry]

Well, then this,

> Following a consistent internal logic given its factual and aesthetic premises.

is better described as "consistent" than as "rational". The language Brainfuck is consistent, but it would be a stretch to call it a rational language to build stuff with.

Rationality carries with it a connotation of deeper underlying symmetry to surface reasoning. The "aesthetic ideals" you're referring to.

A reasoning is different from a rationale. A rational person makes optimal decisions, renorming his expectations as needed. A consistent person makes the same decision over and over based on some unchanging principle.

We want our laws to be rational, not consistent. To seek out an ideal regulation of behavior that's fair and useful to everyone. It is certainly consistent within a specific framing of law that useful actions be outlawed, but it is not rational.

[dragonwriter]

>Rationality carries with it a connotation of deeper underlying symmetry to surface reasoning. The "aesthetic ideals" you're referring to.

I disagree. Rationality is orthogonal to aesthetic ideals.

> A reasoning is different from a rationale.

No, its not.

> A rational person makes optimal decisions,

That's true pretty much only if you are referring to the definition of a rational actor in rational choice theory, in which "rational" has a very special definition that isn't very much like its use anywhere else (since it presumes both perfect and total knowledge of the utilities and disutilities, both immediate and distant, that will result from any choice, and a universal decision rule of action in which the actor always maximizes his own utilities.)

> We want our laws to be rational, not consistent.

"Rational" in the sense it has to make your previous sentence true cannot be applied to laws except as acts of individual legislators, and if it was it would mean that they were acts maximizing the legislators personal utilities.

> To seek out an ideal regulation of behavior that's fair and useful to everyone.

"fair and useful to everyone" is "just", more than "rational".

> It is certainly consistent within a specific framing of law that useful actions be outlawed, but it is not rational.

In the sense that your stated definition of "rational" is an unattainable ideal and, consequently, any real world law regardless of its attributes will be "not rational" by it, I agree; OTOH, I don't think that -- even aside from the fact that "rational" is the wrong word for it -- its really useful to use such a definition in a binary sense to discuss real world laws.

OTOH, using a continuous scale, even the most just law possible is going to occasionally prohibit some acts with social utility.

[vinceguidry]

OK, at this point our disagreement is purely semantic. If you or I were to s/rational/just/g, then we would agree on everything.

I do not agree that the law could never attain rationality/justness. I believe that it can, but it can only ever stay there temporarily. Eventually society will change and make the laws irrational again. Which is why my focus would be on the tuning the machinery of state rather than each individual law. With enough work, we could build a system that anticipates societal changes rather than simply reacts to it.

> OTOH, using a continuous scale, even the most just law possible is going to occasionally prohibit some acts with social utility.

In this case a jury can exercise discretion and refuse to convict someone even when the law and evidence would demand it.

[dragonwriter]

> In this case a jury can exercise discretion and refuse to convict someone even when the law and evidence would demand it.

Right. Or (in the abstract, though there are pretty strong signs that its not the current intention in this case) prosecutorial discretion or executive pardon can be used before or after the point where the jury would get involved. There are numerous tools available to fine tune the justice of the application of criminal law beyond just the scope of its prohibitions, and trying to foresee all the low-probability future possibilities in crafting the statutory prohibitions gets you into nasty trap; you've got to find a balance. And, most importantly, not view criminal law (or any law) as a machine that produces justice automatically without considering the people involved in its application.