(... at least in a pure form, as I understand it.)
I've written before on why I'm not a libertarian, and Clayton Cramer gives many more substantial examples. I definitely have libertarian sympathies, and I think the American government is presently too big, inefficient, and meddlesome, but I'm not enthusiastic about some of the potential results of a pure libertarian system.
Libertarianism sounds good in theory, but in practice I don't trust humans not to devolve to the lowest common denominator once the threat of using physical force to enforce morality is removed. (And simulations support my skepticism.) The question then, as libertarians will be quick to point out, is who gets to decide what's moral? That's a good question.
Libertarians want to design a society that doesn't require any supervision. They want to devise a perfect and limited set of rules to govern humanity without modification forever. They (rightly!) don't trust future governments to use power in a limited way -- even if they happen to think the present government would use power wisely -- so they seek to limit the power of government as much as possible. It makes sense. But I don't think it'll work.
Instead, I think we need a government with a bit more power than a libertarian would prefer, and that we need to exercise constant vigilance to ensure that the government doesn't use its power wrongly. My approach isn't as nice and neat as the libertarian solution, and it requires ongoing effort, but it has the advantage (by my reckoning) of being possible (which makes it more elegant). To a great extent, libertarians (classical liberals) appear to live in as idealistic a fantasy world as do modern liberals.
Mr. Cramer describes some of the characteristics of a pure libertarian society.
If the objective were really libertarian--the only laws allowed would be those that punished one person directly injuring another--and the Constitution was amended (as it would have to be) to achieve this, I could be philosophic about it, I suppose.Mr. Cramer says more in an update to his post, and concludes with:
There wouldn't be any laws against sex in public places, but there also wouldn't be any laws against carrying a gun for self-defense against criminal attack.
There wouldn't be any laws against child pornography, but there wouldn't be any copyright law, either, and a lot of pornography would be much less profitable without copyright.
There wouldn't be any laws against driving drunk (I mean, you haven't really hurt anyone until you have an accident), but then again, there wouldn't be any laws restricting machine gun ownership, either.
There wouldn't be any sodomy laws (not that I am a fan of those, anyway), but there also wouldn't be any law requiring you to hire homosexuals, or rent to them, either.
One of the great hazards of these wonderful ideologies is that the proponents of them are usually so middle class in their morality that they just can't imagine that anyone would actually do these things that right now are illegal. They become so enamored of their elaborate theories that they forget what sort of society they are going to create, when the only standard is physical or economic injury.