It is so very British—that "good taste" argument. But it brings at least two colossal problems along with it, once it is either effectively or informally enshrined in law. First, it fails to identify those moments when free speech must supersede good manners (as, for instance, when cartoonists get murdered for drawing cartoons). Second, it ducks the crucial question of truth. In an amazingly diverse society the remit of good manners has the potential to be so wide that the issue of what is true and what is not, let alone the ability to stand up for what is true against what is not, risks getting lost completely. It may simply become a numbers game. Or a decibel one.

And this is the part of Britain's free-speech problem that is most worrying. Because the idea of free speech which was nurtured in these islands by Milton and Mill, exported across the Anglosphere and perhaps best reinforced in recent years in America by Jonathan Rauch, was founded on the principle that free speech was needed not just in and of itself, but in order that good ideas should chase out bad ones. For centuries proponents of free speech centred their arguments not just on the validity of good speech but the necessity of true ideas.

In the days after Charlie Hebdo it struck me repeatedly that this notion was nowhere to be found in the British discussion. Television presenters and newspapers asked, "What are the limits of free speech?" and "Do we have the right to offend?" as though this was some national stab at a GCSE question. The point that was lost was precisely the one that the staff of Charlie Hebdo and Jyllands Posten knew. If you cannot lampoon bad ideas it means you can only lampoon good ideas. If you must refrain from insulting targets which might harm you then you will be limited to only insulting targets which are harmless. The problem then is not simply that you let bad ideas get a free pass; it means bad ideas have the opportunity to win.

That is why the Islamists have chosen their targets so wisely and so well. In a free exchange and free debate they will always lose. That is why they try to stop the debate. It is the purest fluke of Danish history that cartoons have become the battleground. It could just as well have been a novel, a film or a work of scholarship. What they are trying to stop—and are partly succeeding in stopping—is all of this and more.

Some of us have great confidence of victory in the realm of unfettered ideas. But it is striking how little confidence exists, and how much confusion there is, among those in power. Whether they are fearful of allowing the free debate to occur, dread its short-term rumbustiousness or genuinely fail to understand the nature of the challenges our society faces, this misunderstanding or loss of confidence is disturbing. When the Home Secretary Theresa May addressed the Conservative party's annual conference last autumn she proposed (having failed to prosecute various extremists under existing laws) the possibility of putting "banning orders" on extremist preachers. These would prevent them from speaking in public places. The tangle that a country's counter-terror laws must be in for such a thing to even be suggested is a subject on its own. Having failed to deport or prosecute notorious terrorists the one thing the government knows it can do is crack down on their right to speak.