Fighting words and their consequences

Somebody is in the news recently for allegedly getting assaulted after uttering fighting words. It turns out fighting words are commonly excepted from protected free speech. Contrary to the elementary folklore, free speech appears not to be universal, but is thought to be based on the libertarian principles argued by Mill, that speech which does not do harm to others should not be proscribed. All right, so far this is all common knowledge. But is that all? Is free speech (harm or not) a flawed idea to begin with? There is an old and generally discursive article by Kendall called The “Open Society” and Its Fallacies, which challenges the tenets of Mill’s libertarian stance on speech at its core.
(Read the article)