Fortunately, this is not hard to resolve. It's about overall climate. Just remember that key phrase: overall climate.
Look, I'm committed to tolerance. I'm committed to cultivating a diversity of viewpoints, and I appreciate people around me who disagree with me. Two things to remember:
1. Tolerance does not mean you are exempt from criticism. I honor your right to have an opinion different from mine. As Evelyn Beatrice Hall (British writer, b. 1868) famously said:
"I do not agree with what you have to say, but I'll defend to the death your right to say it."Tolerance generally means you get to say it, but that doesn't mean I don't also get my say. And when I get my say, I might very well choose to be very pointed in explaining how you have misrepresented the facts, and how, even if you had the facts right, they do not support the conclusion you have fallaciously drawn.
If, in the process, I also throw in some rude remarks, ad hominem attacks, and misrepresent some facts myself, then I am being a bad debater, not an intolerant one. As long as I'm not using force (which, when it comes to government tolerance, is known as "the coercive apparatus of the state") to stifle or punish your viewpoint, then tolerance is not an issue.
That much is easily grasped. Here's where people start running aground of difficulties:
2. Tolerance does not even require that we must always abstain from use of force to limit your expression. Generally, of course, we want to let viewpoints be freely expressed. However, "time, place, and manner" restrictions are widely recognized as legitimate. You can have your opinion, and express it, but not in certain places at certain times. And the manner of expression might be inappropriate: you can't yell your opinions at the top of your lungs in the middle of a hospital ward in the middle of the night. In fact, in general, you can't disturb the peace.
In determining what sort of content should not be tolerated, the question is: How do we facilitate the greatest overall climate of tolerance? A given climate of tolerance is greater than another when it yields greater diversity of expression. If we allow hateful bigoted expressions to be freely uttered, or posted on the walls of public institutions, then we inhibit counter-expressions.
We refer to the "free market of ideas" because there is indeed an analogy between the discourse of viewpoints and the free market. If you leave either completely free, then it quickly becomes unfree. For the maximum overall climate of free expression -- just as for the maximally free market -- a little regulation is required.
In 1890, Congress passed the Sherman Act, and in 1914 passed two additional anti-trust laws. We passed these laws because we'd learned that if we left the market entirely unregulated, then monopolies could (and would and did) arise which then stifled other businesses. A big, powerful company could afford to sell products at below cost until the competition was driven out of business -- and thus establish and maintain monopoly control: just the opposite of a free market. We needed to limit the market freedom of powerful would-be monopolies in order to foster greater market freedom overall. If you don't limit the freedom of the bullies to bully, then the bullies will limit everyone else's freedom.
In the same way, it is necessary to limit some hateful expressions. Otherwise, the powerful haters will create a climate intolerant of views different from theirs.
When do we tolerate intolerance and when do we not? The question to ask ourselves is: Does the intolerance in question threaten the overall climate of tolerance? If it is not of such nature or power to have a reasonably discernible chill effect on other viewpoints, then allow it (though do share your criticisms of it). But if the vitriol is driving out other viewpoints, then, in the name of tolerance itself, it should not be tolerated.
Every limitation on expression damages the overall climate of tolerance -- but sometimes it's worth it. Sometimes not curtailing certain expressions damages the climate of tolerance even more.
It may sometimes be difficult to tell what the effects on the overall climate of tolerance are. Sometimes our best judgment might get it wrong -- and we'll end up tolerating something we shouldn't have tolerated, or shutting down some expression which we should have allowed. Applying the criterion won't always be easy. Community is messy. There is no easily-applied criterion, but there is a criterion: maximization of the overall climate of tolerance.