In the Harry Potter universe, the ability to speak and think has extra weight. The use of speech facilitates the intentions behind that speech manifesting directly. “Wingardium Leviosa,” says a first-class citizen of that universe, pointing a magical stick (also used to direct parapsychic energy as with speech), focusing on the object, and it begins to float.
Words can even kill, with the phrase “Avada Kedavra.” But so can words in our universe.
The law recognizes several exceptions to the freedom of speech, and most of these implicate violence. The few others implicate other direct, intentional harms (such as defamation).
In the case of fighting words, the idea is not that one oughtn’t be allowed to speak, but that one ought to recognize that certain words spoken in a specific circumstance are invariably going to provoke a retaliation of violence. This is a practicality of the law, basically saying, “you get what you pay for.”
Ah, but this complicates matters entirely! Some pseudo-Islamic sects and cultures that deviate from the doctrines that purport to adhere to peace take violent offense at any speech that lessens in their eyes the glory of their prophet Muhammad (may His undergarments always fit well). One can only imagine how that doctrine developed.
Sometime Around 633…
Artist: And now I present to you, the Caliphate, the portrait you commissioned of the Prophet Muhammad, may the Blessings of Liberty be secured to Him and His Posterity.
Caliph: Excellent! You really captured His (may there never be clumps of hot chocolate powder in His hot chocolate!) eyes.
Adviser 1: Sir, His (may He always know where His towel is!) nose is too small.
Adviser 2: No, sir, it’s too big, and His (may He never have a Scrabble(tm) rack with no vowels!) jawline is off!
[A fight breaks out. The next visitor to the Caliph happened to be the knife seller. His table is overturned in the ruckus. The third visitor was a fruit seller, and his bananas were knocked from his table. Between all the slipping and all the blades covering the floor, everyone in the area died in a tragic accident that ruined the portrait in the process.]
New Caliph: I decree that no depictions of the Prophet (may He always have positive wishes said for Him in parentheses after someone mentions Him!) shall be made!
Point is, to them any insult to Mohammad (may His taco shell never break down the bottom as He takes the first bite!) is equivalent to fighting words.
But there’s a similar problem for the American Flag, where plenty of people that have no qualms with desecrating the Quran believe that flag desecration should be severely punished.
The main problem with free speech is not these peoples’ outrage. It’s the lack of any assurance of being heard. If someone in a bar insults you, your honor may be irreparably harmed. You may be labeled the village fool. You may be forced to walk the earth the rest of your days being treated poorly. All because of what this drunk guy is saying. You flash down the years of shame and suffering you will have as a result, and decide that pain belongs with your verbal attacker.
If you knew that the bar would listen to your plea that this is all a big misunderstanding, that these words are hurtful and misplaced, and that such a plea would be taken as honorable, it would defuse the situation. The problem is that often the culture sees such behavior as weak, and you’re trying to talk sense to a bunch of drunk people.
In general, intoxicated people can be hard to reason with. Sober people, for that matter.
If someone throws the equivalent of the “Avada Kedavra” killing curse at you, you’re expected to meet force with force.
But if the culture shifts. If the people are well educated, and care more about truth than a bogus sense of honor, not only does the violence decrease, but the offending speech does as well.