Needless to say, none of this is true. Nowhere has Heather Mac Donald suggested that black people or any other type of person has "no right to exist". The accusation is levelled without evidence. But as with all anti-free-speech activists today, the line is blurred not merely between actual words and violence, but between wholly imagined words and violence.

Every week in America brings another spate of defeats for freedom of speech. This past week it was Ann Coulter's turn (yet again) to be banned from speaking at Berkeley for what the university authorities purport to be "health and safety" reasons -- meaning the health and safety of the speaker.

Each time this happens, there are similar responses. Those who broadly agree with the views of the speaker complain about the loss of one of the fundamental rights which the Founding Fathers bestowed on the American people. Those who may be on the same political side but find the speaker somewhat distasteful find a way to be slightly muted or silent. Those who disagree with the speaker's views applaud the banning as an appropriate response to apparently imminent incitement.

The problem throughout all of this is that the reasons why people should be supporting freedom of speech (to correct themselves where they are in error, and strengthen their arguments where they are not) are actually becoming lost in America. No greater demonstration of this muddle exists than a letter put together by a group of students at Claremont McKenna College earlier this month to protest the appearance on their campus of a speaker with whom they disagreed.

Heather Mac Donald is a conservative author, journalist and fellow of the Manhattan Institute in New York. Her work has appeared in some of the world's most prestigious journals. Of course, none of that was enough to deter students at Claremont from libelling her as much as possible in advance of her speech and then preventing her speech from taking place. At Claremont McKenna College, where Mac Donald was due to speak about her recent book, The War on Cops, angry students surrounded the building, screamed obscene words and banged on the windows. Mac Donald ended up giving the speech to a mainly empty room via live video-streaming and then fleeing the university under the protection of campus security. As recent events, such as the hospitalisation of a professor at Charles Murray's recent speech at Middlebury College have shown, intimidation and violence are clearly regarded by today's North American students as legitimate means to stop people from speaking.

The reason, if any, may well come down to the possibility that facts have become diminished in importance on American campuses and have gradually lost out to the greater imperative of short-term political "narratives" and victories that come from thuggish intimidation. A letter sent to university authorities at Claremont ahead of Mac Donald's speech is one of the most important recent documents chronicling the descent of this most crucial American value, freedom of speech.

The letter to university authorities from "We, few of the Black students here at Pomona College and the Claremont Colleges" loses no time in libelling their subject:

"If engaged, Heather Mac Donald would not be debating on mere difference of opinion, but the right of Black people to exist. Heather Mac Donald is a fascist, a white supremacist, a warhawk, a transphobe, a queerphobe, a classist, and ignorant of interlocking systems of domination that produce the lethal conditions under which oppressed peoples are forced to live."

Needless to say, none of this is true. Nowhere has Mac Donald suggested that black people or any other type of person has "no right to exist". The accusation is levelled without evidence. But as with all anti-free-speech activists today, the line is blurred not merely between actual words and violence, but between wholly imagined words and violence. Thus the students write:

"Advocating for white supremacy and giving white supremacists platforms wherefrom their toxic and deadly illogic may be disseminated is condoning violence against Black people. Heather Mac Donald does not have the right to an audience at the Athenaeum, a private venue wherefrom she received compensation. Dictating and condemning non-respectable forms of protest while parroting the phrase that 'protest has a celebrated' place on campus is contradictory at best and anti-Black at worst."

Amid the semi-literacy, linguistic ostentation and intellectual dishonesty, it is hard to single out what is worst about this letter. But, against stiff competition, what is worst is that the whole thing is built on one massive misunderstanding which might also be described as a false premise.

"Historically, white supremacy has venerated the idea of objectivity, and wielded a dichotomy of 'subjectivity vs. objectivity' as a means of silencing oppressed peoples. The idea that there is a single truth--'the Truth'--is a construct of the Euro-West that is deeply rooted in the Enlightenment, which was a movement that also described Black and Brown people as both subhuman and impervious to pain. This construction is a myth and white supremacy, imperialism, colonization, capitalism, and the United States of America are all of its progeny. The idea that the truth is an entity for which we must search, in matters that endanger our abilities to exist in open spaces, is an attempt to silence oppressed peoples."

As the English philosopher Roger Scruton wrote in his book Modern Philosophy, "A writer who says that there are no truths, or that all truth is 'merely relative,' is asking you not to believe him. So don't."

Of course, the students at Claremont go farther than this. They make claims about people that are lies, yet state them as though they are categorical truths. And then they declare that "truth" is a "construct" -- and one that they do not believe in. Their letter makes that plain, without them having any need to state the fact. But that they have stated it is convenient; it saves any honest observer from having to expend much energy considering the validity of their other claims. Anyone studying the decline of education in privileged Western democracies in the early 21st century will find documents like this immensely rewarding as historical testaments, and also a warning of what can happen when the thinking goes wrong.