It would be great if we could just let the marketplace, ideological or economical, operate freely with zero interference, and everything would work out perfectly as a result. However, that's just not realistic. The dog-eat-dog, state-of-nature sort of unrestricted natural selection that Mother Nature oversees is precisely the thing from which Civilization has been trying to protect us, because Mother Nature is a heartless bitch (see the is-ought problem). A splendid, multifaceted, wondrous and downright hot heartless bitch, but a heartless bitch nonetheless. For all that reciprocal altruism and mutually-beneficial cooperation are naturally encouraged, there is still room for the cuckoo - not every cuckoo gets away with it, but enough do. Similarly, con-men are often exposed as the frauds they are, but not always, and many get away with it.
There is no straightforward demand for con-men in the economy, nor is there a need for cuckoos in the biosphere. They do not satisfy any needs or desires. They survive not by contributing, but by exploiting available opportunities at the expense of others in the community (the pocketbooks of the gullible and the genuine progeny of other birds, respectively). Con-men do not create wealth, cuckoos do not fill a niche; both survive by skimming off the top of a system that would, on any analysis, be better off without them.
Con-men are outlawed from existence, cuckoo eggs are killed when discovered. Similarly, in the marketplace of ideas, there are harmful ones that do not contribute to humanity, but instead drag the system down, surviving only by the grace of their betters which got us, as a species, this far in the first place. Slander and libel are the obvious ones: these kinds of ideas so egregiously detract from discourse that they are banned from the process entirely, and prosecuted when discovered. Threats, too, are not allowed into the marketplace, because they accomplish nothing aside from indicating that a certain crime is likely to occur.
But is it enough?
As with the economy, excessive regulation breeds tyranny and oppression, suffocating legitimate contributions and generally doing more harm than good. But how much constitutes "excessive," and who gets to draw that line? When speaking of liberties, I think a good principle is that people should be left as free as possible, with regulations only applied when someone else is harmed - as Jefferson said, "The legitimate powers of government extend to such acts only as are injurious to others." So let's look at the consequences, shall we?
Economic collapse can ensue, as history shows, from either too much or too little regulation. Too much, and there is no incentive to tease the motivations that drive us into action; too little, and short-sighted greed will win out over long-term stability. Even in nature, animals can eat themselves into extinction if the blind watchmaker crafts too prolific a form. We have not yet seen what total ecological collapse looks like from the inside (yes, we are inside the ecosphere, and just as much a part of nature as everything else), we have only been able to look back upon past catastrophes foisted upon our tiny blue bubble. What is good in the long run, what is often called "the right thing to do," can often be a thin line walked carefully between two extremes.
What would a collapse of the marketplace of ideas look like? What would the proper analogue be, exactly? Cultural stagnation, even regression, could follow from over-regulation, as only the blandest and most insipid fare could pass the test of too many timid cooks objecting to flavors they dislike, instead of sucking it up and just eating a different meal. There is no single thing that will fail to offend absolutely everyone - I, for one, find the bland to be offensive for precisely the reason that it cowers behind political correctness at the expense of thought-provoking content. It drains ideas of their power in the name of coddling people like children who can't be trusted to think for themselves. It is an insult of enormous magnitude: you can't be trusted with this thought, but we can administer your thoughts by filtering what we decide is or is not appropriate. I'll take a pass on that, and to hell with you for offering!
But what would excessive deregulation cause? Not in advertising, mind you - that falls under the purview of the economy. Hmm... now that I think about it, perhaps not. All media, after all, has economic roots. Maybe that's not a fair distinction to make. But that's a topic for another day, the matter at hand is whether our current system permits too-free speech, and how the marketplace of ideas could conceivably thereby collapse. Leaving aside slander, libel, and false advertising claims, what are the dangers of unregulated discourse? How bad could it possibly get? I've been staring at my screen, trying to imagine something - anything - but the only thing I can come up with is: feelings get hurt.
Cry more, why don't you?
Ideas are not a resource like money or food is a resource: they are not consumed or spent, but can only spread or stagnate. False advertising claims, slander, libel; these have all been outlawed from our marketplace of ideas1, and I think that's enough. There are particularly nasty and infectious ideas that will no doubt spread regardless of any other merits, but the way to combat them is not to censor them like the child on the playground who thinks words are magic and says, "Ooh, you can't say that!" Rather than censoring them, we should let them fend for themselves just like any other idea, because the idea that they're precious and oh-so-special is itself just another idea, and for that matter, so's the idea that free speech is good. Feelings will get hurt, to be sure - but you know what? Offense is very different from actual harm. A little alienation is good, every now and then2. Having your beliefs called into question is good for you. Examining your thought processes is good for you. Learning to deal with ridicule is good for you. Being able to take a joke is good for you.
And, perhaps most importantly of all, learning to get along with those who disagree with you, sharing your ideas and staying civil with each other, is good for you.
Too much of anything is bad for you, of course, and the same applies to all of the above. We should not perpetually question our beliefs, or we would be paralyzed by doubt. Constantly examining our thought processes leaves us locked in the ivory tower, never acting in the world outside. Too much ridicule can break the human spirit. Too much jocularity leaves no room for Serious Business. Having a ready defense of every single opinion is impossible.
And getting along with those who harm others, instead of helping their victims and working to abolish the tyranny du jour, is morally bad. Just so this is perfectly clear, I'm looking at you, Saudia Arabia, Zimbabwe, Darfur, Pakistan, Somalia, Sudan, South Africa, Russia, Bosnia, Kosovo, Britain, and especially you, America - the way you grew up, knowing what you've been through, and now seeing what you're putting others through - what would your founders think?
Whoah, kinda got sidetracked there. To the OnTopicMobile!
Actually, my diatribe gland is starting to feel a little dry. I've looked it over, and I am again sure that free speech is not negotiable. Freedom is simply too important to be held in check by the whims of others' feelings. I think I can say with confidence that if anyone doesn't like that, they've got some serious growing up to do.
1. False advertising claims, slander, libel; these have all been outlawed from our marketplace of ideas. Not entirely, actually. This seems a little too easy, to be honest, but I'm going for it anyway. Religion makes claims that it can't support; several make libellous claims about unbelievers. I do not advocate book-burning under any circumstances, I'm just saying that in a religious context, we as a society still have trouble recognizing these otherwise criminal statements for what they are (or, perhaps more appropriately, classifying them more accurately as "fiction").
2. A little alienation is good, every now and then. Thanks to Peter Railton for this bit. For more on this, or just to read a good paper, check out Alienation, Consequentialism, and the Demands of Morality.