Just as Star Trek's Captain Kirk never said "Beam me up, Scotty", so Voltaire never said "I disapprove of what you say, but I will defend to the death your right to say it".

Instead the latter is thought to capture the essence of Voltaire's outlook, which roughly translates to: 'Free speech means very little unless it is extended to those with whom one disagrees'.

This is a fairly solid injunction most of the time. The idea that certain ideas are beyond criticism because doing so equates to an attack on the individual believer is usually a sinister attempt to assert ideological supremacy. People should be respected rather than ideas, and respecting someone as a person often means telling them that they have put their faith in codswallop.

But many of Voltaire's twenty-first century disciples interpret the enlightenment writer differently. They may disapprove of what someone has to say, but they will seemingly defend to someone else's death that person's right to say it.

The latest round of loud expostulation over the supposed shutdown of free expression has come in response to last Wednesday's cancellation of an event by Milo Yiannopoulos at the University of California, Berkley. The talk by the high profile online troll marked the final stop in the euphemistically known 'controversialist's' tour of American campuses. Or at least it would have done; in the end, the event did not go ahead after a 'black bloc' riot by anarchist groups resulted in its cancellation.

The fact that Yiannopoulos (I refuse to call him Milo as he is not my friend) was denied a platform at the university is widely being interpreted as a violation of both his right to speak and the right of his audience to listen. Voltaire is again being resurrected from the wrong grave and his supposed essence is being bandied around to bash the illiberalism of 'generation snowflake'.

What is not being acknowledged in the clamour to defend Yiannopoulos's right to a platform (not his right to speak by the way, which no one is denying) is the notion that certain freedoms are not always compatible. Mainstream opinion-formers typically accept this when democratic norms are threatened by, say, non-violent jihadist preachers. However, they are often ready to behave far more leniently when it comes to the white far-right.

It is important perhaps to examine the 'freedom' Yiannopoulos intended to exercise at the University of California. At a previous talk at the University of Wisconsin, Yiannopoulos incited his mob of followers to abuse a trans student. Similarly, there were rumours that Yiannopoulos planned to publicly name undocumented students at his cancelled Berkeley University event (though he denied this). Yiannopoulos was also previously banned from Twitter after inciting a foul-mouthed mob of online inadequates to send hate mail to the black actress Leslie Jones.

 Milo Yiannopoulos
Conservative columnist Milo Yiannopoulos holds a press conference near the Pulse Nightclub, June 15, 2016 in Orlando, Florida Getty Images/Drew Angerer

At the very least, then, you might say that Yiannopoulos's freedom to take to the stage on campus is conditional on certain students walking around with the threat of abuse or even violence hanging over them. Inciting the persecution of minority students is after all not simply an opinion, but is an aggressive action that might very well justify a defensive response.

It is for a similar reason that Reddit has taken the step of banning alt-right discussion forums: the platform was being used to 'dox', a form of public shaming in which the phone numbers and addresses of alt-right targets were being published in order to publicly shame them. Reddit's actions have not prevented anyone from expressing their opinion; but nor is the company obliged to give a platform to those who would use their freedom to crush others like a beetle under the foot.

The alternative – a cordial realm where the persecuted can peacefully debate their right to exist with their persecutors – exists only in the minds of the most unworldly liberals. In this respect, free speech absolutists make a similar mistake to free market utopians: they fail to grasp that some things are mutually exclusive. Just as my 'freedom' to buy up all the houses along my street may impede your right to find somewhere affordable to live, so granting members of the 'alt-right' a platform to whip up hatred can impinge on the freedom of those on the receiving end of it.

On both sides of the Atlantic, the alt-right and similar trolls have plenty of platforms as it is. Students are no more obliged to lay down the red carpet for movements that wish to violently restrict their freedom (it is still violence when a part of that movement gets into power and the state enacts it) than a farmer is obliged to welcome a fox into his chicken house. Nor can the state be relied upon to protect students from a resurgent fascism: there are already reports of far-right infiltration of US law enforcement agencies.

Public life is currently awash with lazy comparisons to the 1930s. Pundits of all stripes are engaged in a fascist-spotting exercise where they are forever on the lookout for something with a silly moustache, an arm flung up wildly in the air, and a passing resemblance to the fiction of Philip Roth or George Orwell. Yet fascism today is smarter than that: it is media savvy, it has (for the most part) ditched the openly genocidal rhetoric, and it is adept at cloaking itself in a penumbra of the little guy 'telling it how it is'.

What has not changed is fascism's incompatibility with democracy. Granting fascists the right to participate in the democratic 'marketplace of ideas' is the equivalent of giving a tumour jurisdiction over a part of your body. It does not care if you are vain enough to think you can reason with it. It simply wants to take over its host and, upon successfully doing that, it will proceed to kill it.

James Bloodworth is former editor of Left Foot Forward, one of the UK's top political blogs, and the author of The Myth of Meritocracy. Follow : @J_Bloodworth