Almost half a century ago, just before his murder, Malcolm X spoke at the Oxford Union to the motion that "extremism in the defence of liberty is no vice; moderation in the pursuit of justice is no virtue".

In 1964, listeners were left uncomfortable. Their children have no reason for complacency today.

Where are the limits when freedom requires a defence? How moderate can a society afford to be when the idea of moderation is regarded as a challenge by those who would strip of us moderate tolerance? In essence, how much liberty can you afford to lose for liberty's sake?

Democratic governments do badly with such questions. On the one hand, they can never be too careful. Had anyone forgotten, the slaughters in Paris were a reminder of threats all too real. Equally, there is the knowledge that we have lost the contest if we turn our world into a police state in freedom's name. The paradox is the essence of Orwellian.

Who are we if we cannot speak freely? How is extremism defeated if we begin to invigilate even nurseries for "signs of radicalism"? The Home Office takes its precautionary instincts to another extreme. Bluntly - and in the name of free speech - we should say that this is utterly foolish.

Would you have your child "monitored"? Would you wish to see universities, bastions of free thought, turned into places where individuals are vetted at a bureaucrat's whim? By those lights, Malcolm X would have been locked up long before he planted incendiary phrases in the heads of Oxford students. Would that - just to be on the safe side - have been right?

No one who has ever enjoyed the right to voice a thought could agree to such a thing. No newspaper, born of hard-won freedoms, could agree to "background checks" for lecturers, or turning childminders into spies. Will we - for such is the logic - vet journalists? It amounts to this: one part of the liberty we defend is the right to tell the Home Office not to be so perniciously silly.

It's also possible, meanwhile, that the fine minds of the Civil Service have not thought this through. Does Draconian anti-terror legislation apply if education is a devolved matter? What's the view of Scotland's government on child-minders and tiny potential terrorists? Where stand the ancient liberties of Scotland's seats of higher learning - guaranteed under Acts of Union - when someone in Whitehall decides to vet a speaker?

Let's not get carried away. Among our freedoms, common sense ranks as high as any. It is a better weapon against preachers of hate than any oppressive law. Those who promote terror are desperate for victimisation. That's one good reason to deny them their desires, tell the Home Office to remember what we defend, and cling to a word: normal. Our dull, unglamorous duty is to defend normality.

If the government persists - and that much we can doubt - this newspaper might have to resort to quoting Malcolm X, Milton, Burns, and George Orwell. Today, perhaps, Winston Spencer-Churchill would do. In 1938, he warned that "the stations of uncensored expression are closing down". He would be alive to all the ironies now, and warn us against them. The Home Office must think again.