Since I accept the classic rights of life, liberty and property I am reluctant to endorse restricting free speech. However, as I have argued before, liberties are not absolute. As I have also noted in other essays, I make use of Mill’s principle of harm as a general tool when assessing the limits of rights. So, in the case of free speech I favor the liberty of expression until it inflicts meaningful harm on others. Sorting out the level of meaningful harm is certainly problematic.
While some contend that offensive speech should be limited, that is unreasonable. After all, while people do not like being offended, it does not harm them in any meaningful way. To use an analogy, it is like getting a small spatter of muddy water on your pant legs from someone driving a bit too close to the sidewalk on a rainy day—not enjoyable, but nothing that causes lasting harm. While it can be rude to intentionally offend people, there are no grounds for compelling people to not offend.
Some people like the idea of placing limits on speech based on how the speech makes members of the audience feel—if someone feels threatened or is frightened by the expression, then it should be restricted. While this does have some appeal, there is the obvious problem that people have varying thresholds of fear and some of these can be quite unreasonable. To use an analogy, someone might find a person with facial piercing frightening and threatening, but this hardly warrants restricting facial piercings. It can, of course, be rude or mean to intentionally frighten people who are easily frightened, but the fact that some people are easily frightened does not warrant unreasonable restrictions.
The notion of hate speech has also been advanced as a standard for placing restrictions on speech. While this also has some appeal, there is the challenge of defining what counts as hate speech and what sort of hate speech crosses from being merely offensive or frightening to cross over to an actual imposition of harm that warrants restriction. While people do often want to silence people who express hatred of them, this does not seem to reach the level of meaningful harm that would warrant restrictions. The challenge, then, is sorting out some boundaries of free speech. Because of considerations about the line drawing fallacy, it would be unreasonable to demand that exact lines be drawn—at best what can be offered is some general boundaries. This does, of course, create a problem for those who are concerned with legal restrictions on expression—the laws, after all, need to be as clear and precise as possible. That said, fuzzy laws are routinely tolerated and accepted (such as laws relating to obscenity and pornography).
While some people do advocate a nearly absolute right of free speech and think that, for example, Nazis should have the freedom to march and do Nazi things in the middle of Holocaust memorials, it is worth teasing out intuitions about free expression. I will start with an easy, albeit horrifying, example.
Suppose a group formed dedicated to the theory that raping infants is correct behavior and they wanted to march through the streets advocating this activity. Obviously enough, people would point out that the activity they are advocating is a crime (and morally horrible). Imagine that the spokesman for the group insisted that they were just advancing an idea and were not, in fact, engaging in any actual rape. Just like the Nazis who claim a right to free speech because they are just presenting their views and not actually engaged in acting in accord with them (by murdering Jews, for example). The raises the question of whether things that would be morally horrible (and illegal) to do should be protected by free speech rights when they are merely defended or advocated.
As another example, consider whether American representatives of groups like Al Qaeda and ISIS should be allowed to peacefully march the streets of the United States while advocating their beliefs in speech. At this point, some readers are thinking the obvious: these are foreign terrorist groups and people can be arrested for belonging to them or supporting them. But, the issue at hand is not the legality of such groups, but whether their speech should be restricted on moral grounds because they are evil. If American Al Qaeda and ISIS advocates agreed to be as peaceful in their marches as American Nazis, would they be morally entitled to the same free speech rights? After all, Nazi ideology and Al Qaeda ideology are both foreign ideologies committed to the destruction of the United States and both groups have made war on America and murdered Americans. I am, of course, aware of the legal issues regarding Nazis and Al Qaeda—but, once again, this is a question of ethics.
As a final example, consider an imaginary group: Ameriqaeda. This group is composed of Americans that advocate Islamic supremacy, peaceful imposition of Sharia law and the peaceful religious cleansing of Christians from the United States. The group claims it has no affiliation with terrorist groups, although violent people seem oddly drawn to their events and sometimes kill a Christian or two. Should this group have the freedom to express its views and march? Would Fox News and Trump rush to defend their free speech rights and assure us that there are good people on both sides? Or would such a group cross a moral line that white supremacists that advocate white supremacy and peaceful ethnic cleansing do not cross? Or would it merely be a prejudice against Islam in general that would lead people to forbid Ameriqaeda to march with the same freedom as white supremacists?